Version 2.2 - June 8, 1992
1. General description
LISE is a program to calculate the transmission and
yield of fragments produced and collected in a zero degree achromatic spectrometer.
This method has been used for several years to produce and select radioactive
nuclei far from stability, and is now opening a new era in nuclear physics
research through the production of radioactive secondary beams. The program
is designed to be as user-friendly as possible, and to be used not only
before an experiment to forecast the settings, rates and contaminants,
but also during the run for the identification of the different nuclei
and charge states, and to allow the experimenter to recalculate anything
quickly and easily in case some parameter of the experiment has been changed
(different selected nucleus, different detector, ...).
2. List of features
2.1. Simulation of experimental
The program adapts to any spectrometer operating
in the achromatic mode by adjusting the relevant optical parameters.Adapts
to a Wien filter installed after the spectrometer.Free adjustment of the
geometrical and momentum acceptances as well as slits to determine the
selectivity of the whole apparatus.Stacks of up to 7 different materials
at the focal plane of the spectrometer (or Wien filter) in order to simulate
the slowing down and/or implantation media for the different transmitted
nuclei.Adjustment of the parameters related to the production mechanism
simulated in the program. E.g. a realistic cross section of a different
reaction process used in the experiment can be specified.
2.2. Calculations performed
The Br settings of the
spectrometer and electric (or magnetic) field of the Wien filter for the
best transmission of a given fragment.The Br
of any charge state of any transmitted nucleus (specially useful to keep
track of the beam charge states).The Transmission of any fragment at a
given setting of the fields. These numbers are then multiplied by the beam
intensity, the target thickness and the cross sections to give an estimate
of the rates. Angular and energy straggling are taken into account in the
transmission calculations.The optimal target thickness can be calculated.The
kinetic energy, the energy loss in a given material thickness, the range
and both angular and energy straggling at different positions in the spectrometer.
The range and energy loss calculations can be performed at any energy (although
the valid range is from 2.5 MeV/u to 500 MeV/u) for elements Li through
U into materials Be through U. The program `remembers' the range tables
whenever they are calculated by storing them on disk.Calibration of either
the beam energy or the target thickness using a charge state of the beam
and the Br at which the ion is centered on the
dispersive focal plane. The same feature for calibrating the wedge thickness
using any transmitted nucleus is provided.The program includes the possibility
to calculate the charge state distribution of any fragment and the corresponding
The results of the calculations are displayed on
a "chart of the nuclides" which can be scrolled in order to see the results
obtained for a different region of nuclei (the screen contains 7´
7 nuclei). Two pieces of information per nucleus can be chosen from the
list of transmission, charge state distribution, cross section and final
rate.It is possible to add (or remove) any nucleus to the nuclear chart.
If a new nucleus has been added, the automatic calculation of rates will
take it into account. The chart of nuclides is updated each time the program
is terminated.One of the main features of this program is to produce an
identification plot (Energy loss vs Time Of Flight). The parameters of
this plot can be adjusted. They include the material in which the particles
lose their energy, the flight path length, and other things such as the
High Frequency of an accelerator (cyclotron) in case it is used as a time
reference (this method usually leads to a wrap around of the identification
plot).Display of Energy loss vs Total Kinetic Energy using the same conditions
as for the identification plot.The distributions calculated for the transmission
of the fragments can be displayed together with the acceptances or slits
positions in order to visualize the selections and cuts created by the
spectrometer. These include the angular distributions after both the target
and the wedge, the Br distributions at the dispersive
focal plane, the position distributions at the first focal plane (after
the wedge) and at the second focal plane (after the Wien filter in case
it is used).The implantation distribution can also be displayed in any
of the 7 chosen materials.
2.4. Files and results output
Any set of parameters and calculations can be saved
in a file and later recalled.The results of the calculations can be stored
in a separate file. This file is automatically printed when a printer is
connected to the computer. Right now, the only way to copy the graphic
screens produced by LISE is by using the "Print Scrn" key and hope that
the PC has been correctly configured to produce a valid screendump. Postscript
files of the graphic screen will be available in the next version.
2.5. User-friendly features
The program uses a pop-up menu structure relying
on the mouse to select the commands and functions. Different parameters
also appear in these menus and they are constantly updated. They can be
changed by simply selecting the corresponding item and then entering the
new value. Once a command has been issued, one can recall the last submenu,
or start again from the root.
3.1. Reaction mechanism and
The production reaction mechanism assumed in this
program is the so-called projectile fragmentation, as pictured for example
by the abrasion model followed by sequential evaporation by both projectile
and target spectators (fragments). Although this picture has been shown
to be fairly accurate at high energy (above a few hundred MeV/u), the reaction
mechanisms goes over to energy relaxation processes such as deep-inelastic
or incomplete fusion in the intermediate energy range (between 30 MeV/u
and 200 MeV/u). Therefore the model may produce incorrect cross sections.In
the program the cross sections are calculated according to a global fit
to fragmentation (fit by K. Sümmerer ) with no energy dependence. For
the production cross sections of nuclei far from stability, the values
provided by this fit are valid only within one to two orders of magnitude:
we have observed systematic deviations of the predicted rates coming from
the lack of data in the cross section fit for the production of nuclei
close to the drip-lines. Therefore the possibility to input directly the
cross sections for a given reaction is included, provided these were actually
measured or calculated by more sophisticated codes. It is also possible
to calculate the transmission and rates for transfer products (i.e. for
"fragments" having more protons and/or neutrons than the projectile). In
these cases the fit based on target fragmentation only gives a qualitative
guess, and a better estimate of the cross section is needed in order to
obtain reasonable yield predictions. Once the cross sections are manually
input in the program they are automatically saved whenever a set of calculations
is saved in a file.
3.2. Beam optics
The spectrometer is assumed to function in the achromatic
mode. This statement implies the following:The spectrometer is composed
of two sections : a first part which is dispersive, and a second part in
which the fragments are refocused, providing the achromatism.At the focal
plane of the first section (called "intermediate focal plane") the horizontal
position (perpendicular to the beam axis) of the fragments only depends
on B( and their horizontal position at the target. Therefore, the two optical
parameters which determine the horizontal distribution at this focal plane
are the dispersion (x/d r
/r ) and the magnification (x/x).A wedge can
be installed at the intermediate focal plane. This wedge is assumed to
be achromatic (i.e., providing the same dispersion after as before). The
proper slope can be calculated in the program.The focal plane of the second
section being achromatic, there is no momentum dependence of the final
horizontal position (as well as vertical). Consequently, the only optical
paramenter taken into account in the determination of the final image size
is the magnification from the target to the achromatic focal plane(called
"image 1").In addition to the achromatic spectrometer previously described,
the program can calculate the selection provided by an additional Wien
filter (velocity filter). The velocity dispersion created by this device
is assumed to occur in the vertical plane, the resulting image (called
"image 2") is determined by the magnification and the dispersion of the
filter (this last parameter is automatically calculated from the physical
dimensions as well as the electrical and magnetic fields set on the filter).
3.3. Acceptance and transmission
The selection of the nuclei transmitted through the
spectrometer is separated in three steps corresponding to three different
criteria:The first section of the spectrometer provides a B( selection
depending on the Av/Q ratio of each nucleus (A being the mass, v the velocity
and Q the ionic charge). The horizontal slits at this first section focal
plane ("Slits intermediate focal plane") set the momentum acceptance.In
case an achromatic wedge is used at the dispersive focal plane, different
nuclei are refocused at different horizontal positions at the second focal
plane, depending on the different amounts of energy they lose in the wedge,
and the dispersion of the second section. This provides a second selection
criteria which depends also on the horizontal size of the beam spot on
target ("Object size"), the magnification, and setting of the horizontal
slits at the second section focal plane ("Slits first focus (after wedge)").Finally,
the third selection is the velocity selection provided by the Wien filter
(optional). Here again the relevant optical parameter are the magnification
and the dispersion. This third selection criteria being different from
the two previous ones, allows a further selection of the nuclei after the
slits (called "Slits second focus (after Wien)").The other acceptances
taken into account for the calculation of the transmission are the geometrical
acceptances after the target and after the wedge. Their values can be set
in both the horizontal (q ) and the vertical
(f ) planes. The maximum Br
acceptance of the device can also be set and is used as an upper limit
for the slits of the intermediate focal plane.In all the calculations mentionned
above, both the energy and angular straggling in the target and the wedge
are taken into account. The effect of the energy loss in the wedge on the
size of the image at the first focus is also included . These effects,
in addition to the fixed range of the particles, limit the maximum thickness
one can accept before starting to lose particles. The best target and wedge
thicknesses result from two compromises. The first is the balance between
the rate increase due to a larger number of interacting nuclei in the target,
versus the decrease due to the slowing down of the fragments which reduces
the actual momentum acceptance, and the angular and energy straggling.
The command "Optimal target" calculates the dependence of the fragment
yield on the target thickness, and finds the "best" target thickness with
the maximum rate. The second compromise concerns the wedge thickness and
is a balance between better selectivity - the images of different nuclei
are further apart when increasing the wedge thickness - and rate loss due
to angular straggling, secondary reactions (which are not taken into account),
and image broadening.
3.4. Energy loss and range
The energy losses are calculated according to the
latest functions provided by F. Hubert et al. . These calculations are
valid between 2.5 MeV/u and 500 MeV/u. Whenever an energy loss and range
calculation needs to be performed, the program looks for the range table
corresponding to the beam-absorber pair on disk. If it doesn't already
exist, the program calculates it (a display appears on the screen) and
stores it on the disk (files TABZ1Z2.RAN in the sub-directory "\RANGE").
Thus, the tables of range data are built up over time. These range tables
are calculated using Simpson's rule for integration, and the energy losses
are deduced by inverted-interpolation on the range.The starting point for
the integration is given by range tables of Northcliffe and Schilling 
at 2.5 MeV/u (files NORTH*.RAN in the sub-directory "\RANGE").Between 0
and 2.5 MeV/u the range is calculated linearly, matching the value at 2.5
MeV/u. Above 500 MeV/u a power function fit is used as an extrapolation
from the last points of the table.
4. Detailed operating description
4.1. Mouse handling in menus
As soon as the program is started the mouse appears
as a small smiling face enclosed in the active area of the menu. Clicking
on either of the mouse buttons (they are equivalent) opens the main menu,
and the mouse is automatically placed at the top center of this new menu.
By scrolling the mouse up and down with the buttons released, one can select
an item of the menu, which appears high-lighted on a black background,
the smiling face dissapearing. Once an item has been selected, clicking
will activate the corresponding action. This allows the user to go down
in the menu structure. To go up (go back to previous menus), just move
the mouse out of any selection to make the smiling face reappear and click.When
a nucleus is required from the chart of nuclides, one has just to point
to and to click on the desired nucleus. To scroll the chart in any direction,
move the mouse to the side from which the chart has to appear (the face
will change into an arrow), and click. If the button is held down, the
chart will scroll faster after a fraction of a second. Placing the mouse
at any corner of the chart will make it scroll diagonally (hence allowing
"isospin" and "isobaric" scrolls).Once an action has been performed, the
program displays again on the top line the choice between "Previous menu"
or "Main menu". One can jump back to the depth from which the last action
was executed by selecting "Previous menu", or start from the root by selecting
"Main menu". Some calculated results are displayed in a window centered
on the screen. This window is automatically suppressed when clicking again
to ask for another action.
4.2. Keyboard entries
Some information is entered via the keyboard. In
every case, one can erase characters using the "delete" key, and terminates
the entry by striking either "return" or "enter". This is also true when
entering data directly into the menus : the cursor is placed where the
entry should occur, and the data is reformatted to fit into the menu (this
means that the format in which it appears in the menu might be different
from the format in which it has been entered).
4.3. Description of each
command following the menu structure
Previous Menu: returns
to the menu previous depth.
Main Menu: goes to the
Settings: calls the
Projectile: calls the
Target: calls the target
Nature, mass and charge:
the programs displays the chart of nuclides surrounding the current projectile
(40Ar by default) and asks to click on the desired new projectile
(one can scroll the chart in any direction to access a different area).
The new projectile will then flash red on the chart, and the program asks
for its ionic charge (this parameter is only used to convert enA into pps).
Any previous transmission calculation is cleared by this command. The program
then automatically asks for the energy and intensity, assuming these parameters
are different for a different projectile.
Energy: asks for the energy
of the projectile (in MeV/nucleon). Previous calculations are cleared.
Intensity: asks for the
primary beam intensity. The unit can be enA or pps depending on how the
intensity unit option is set (see the Options menu) The default is enA.
Previous calculations are cleared.
Wedge: calls the wedge menu.
Nature: selects the periodic
table menu to choose the element corresponding to the target. Then automatically
asks for the thickness. The mass used corresponds to the natural abundance
of the selected element (this holds also for the wedge and material(s)).
Clears previous calculations.
Thickness: asks for the
thickness of the target. The unit can be mg/cm2 or (m depending
on how the thickness unit option is set (see the Options menu). Clears
Material(s): calls the material(s)
Nature: same entry than
for the target.
Thickness: same entry than
for the target. The thickness entered here corresponds to the thickness
seen by the particles travelling on the beam axis (i.e. at the middle of
the dispersive focal plane).
Material \#1..7: selects
on which material the action will take place.
Production mechanism: calls
the production mechanism menu.
Add: calls the periodic
table menu to choose the element of the material. Then asks for its thickness.
This command allows to add or insert a new material.
Remove: removes the specified
Change: changes the nature
and/or thickness of the material by first calling the periodic table menu
and then asking for a new thickness.
Setting fragment: allows
the user to pick the fragment on which the field calculations will be performed.
The program places the chart of nuclides on the previous setting fragment
and waits for a new one. Once it has been selected (same entry style as
for the projectile), it flashes purple at the center of the screen. Clears
sets the ratio of the velocity corresponding to the maximum of the momentum
distribution over the beam velocity. The default value is 1.
Sigma0: sets the reduced
width of the momentum distribution. The final width is calculated according
to the Goldhaber formula:
where AF and AP are the fragment and projectile masses
respectively. The default value is 90 MeV/c.
Spectrometer: calls the
Slits: calls the slits
Dipoles: calls the dipole
Object size (2 sigma): this
command asks for the size of the beam spot on the target. The beam spot
is assumed to be gaussian in both horizontal and vertical directions with
the same width. The number entered is sigma. This parameter plays a very
important role in the wedge selection, since it determines the size of
the images corresponding to different nuclei at the first focus. The smaller
these images are, the better the selection can be by closing the slits.
Previous calculations are cleared when issuing this command.
Slits intermediate focal plane:
sets the slit width at the dispersive focal plane. These slits determine
the Br acceptance of the spectrometer, which
is automatically calculated and displayed in %. The maximum opening is
set by the maximum momentum acceptance parameter (see the Acceptance menu).
Previous calculations cleared.
Slits first focus (after wedge):
the slit width at the first focal point. These slits are important when
a wedge is used, since the images corresponding to different nuclei are
spread out in position. Closing the slits will therefore allow a better
selection of the nuclei which are focused at or close to the center. Previous
Slits second focus (after Wien):
the slit width at the second focal point, which is the focal point of the
Wien filter. They therefore set the velocity acceptance of the filter,
allowing to select more or less nuclei, depending on the velocity dispersion.
Only valid if the Wien filter has been enabled (see the Options menu).
Clears previous calculations.
Wien filter: calls the Wien
filter menu. The following commands are valid only if the Wien filter has
been enabled (see the Options menu).
Brho 1: this command allows
the user to enter the Br of the first section.
This is useful when an experimental value has been determined (e.g. by
centering a charge state of the beam on the dispersive focal plane), and
one wants to calibrate either the beam energy or the target thickness (see
the Calibrations menu). The Br of the second
section is automatically recalculated for the best transmission of the
selected fragment. Clears previous calculations.
Brho 2: allows the user
to enter the Br of the second section (after
the wedge). It can be used to calibrate the wedge thickness when the image
of a beam charge state or of an identified nucleus has been experimentally
centered at the first focal point (see also the Calibrations menu). Clears
Radius 1: radius of the
first section dipole(s). Used to display the value of the magnetic field
on the screen. The default value is the radius of the GANIL LISE dipoles.
Radius 2: radius of the
second section dipole(s).
Acceptances: calls the acceptances
Electric field: sets the
electric field of the filter in kV/m (the user has to know the gap between
the electrodes). Calculates the magnetic field for the best transmission
of the selected fragment and the dispersion. All these calculations are
then updated on the screen. Clears previous calculations.
Magnetic field: sets the
magnetic field of the filter in Gauss, calculates the electric field for
the best transmission of the selected fragment and the dispersion. Clears
Dispersion coefficient: coefficient
used to calculate the velocity dispersion in mm/% according to the formula: D=KE/(Br 2b)
where E is the electric field in kV/m, Br2
the Br of the second section of the spectrometer
in Tm, and ( the velocity of the particle. This coefficient depends on
the field set on the quadrupoles used to focuse the beam after the filter.
Clears previous calculations.
magnification between the object (target position) and the filter. Clears
Electric length: effective
electric length of the filter taking into account the fringe fields. Clears
Magnetic length: effective
magnetic length of the filter taking into account the fringe fields. Clears
Optics: calls the optics
Maximum momentum acceptance:
parameter is used as an upper limit for the setting of the slits at the
intermediate focal plane.
acceptance: horizontal angular acceptance after the target (in degree).
Clears previous calculations.
acceptance: vertical angular acceptance after the target (in degree).
Clears previous calculations.
acceptance: horizontal angular acceptance after the wedge (in degree).
Clears previous calculations.
acceptance: vertical angular acceptance after the wedge (in degree).
Clears previous calculations.
Options: calls the options
Dispersion 1: horizontal
dispersion of the first section of the spectrometer in mm/%. Clears previous
Dispersion 2: horizontal
dispersion of the second section of the spectrometer in mm/%. Clears previous
Magnification 1: horizontal
magnification of the first section of the spectrometer. Clears previous
Magnification 2: horizontal
magnification of the second section of the spectrometer. Clears previous
horizontal angular magnification at the wedge position. This parameter
is used in conjonction with the wedge ( acceptance to calculate the transmission.
Clears previous calculations.
vertical angular magnification at the wedge position used with the ( acceptance.
Clears previous calculations.
Angle on target: Offset
of the angular distributions at the target position in the case the beam
is tilted with respect to the spectrometer axis. Clears previous calculations.
Cross sections: calls the
cross section menu.
Wien filter: switch used
to enable or disable the calculations for the Wien filter. Clears previous
Thickness unit: toggles
between mg/cm2 and (m for the unit used in all thicknesses entries. The
default is mg/cm2.
Intensity unit: toggles
between enA and pps for the beam intensity entry. The default is enA.
Display 1: calls the display
menu to select the first line of information displayed on the chart of
nuclides. The default is the total transmission.
Angular transmission: displays
the angular transmission (in %) as the first number displayed for each
nucleus of the chart for which a calculation has been performed. The angular
transmission is the product of the target and the wedge angular transmission,
both being calculated as the average between horizontal (q
) and vertical (f ) transmissions.
Brho transmission: displays
the Br or momentum transmission (in %) calculated
at the intermediate focal plane.
Wedge transmission: displays
the transmission (in %) calculated at the first focus (after the wedge).
Wien transmission: displays
the transmission (in %) calculated at the second focus (after the Wien
Total transmission: displays
the total transmission (in %) which is the product of the four transmissions
Cross section: displays
the cross section (in mb) used in the calculation of the production rate.
Charge state ratio: displays
the charge state fraction (in %) corresponding to the charge state selected
on the chart (see the Charge state displayed option).
Production rate: displays
the production rate (in pps) estimation based on the transmission, cross
section, beam intensity, charge state ratio and target thickness.
Display 2: calls the display
menu to select the second line of information displayed on the chart of
nuclides. The default is the production rate.
Cross section: toggles between
analytical (cross sections automatically calculated) and file (cross sections
entered manually and stored on file) for the cross sections used in the
calculations. Clears previous calculations.
Charge states: enables or
disables the calculation of the charge state distributions and their corresponding
transmissions. Clears previous calculations.
Charge state displayed:
selects the charge state (entered as C in Q=Z-C) displayed on the chart
Calculation threshold: lower
limit of the production rate. The calculations are neither displayed nor
stored if the rate is below this threshold.
Isotopes: calls the isotope
Enter a value: the program
waits for the selection of a nucleus from the chart and then prompts for
the value of its cross section in mb. This value will only been used if
the cross section option is set on "File".
Read a value: displays the
cross section (analytical value or both analytical and file values if this
last has been entered) of the selected nucleus.
Add a nucleus: calls the
menu used to select the type of nucleus. Once this selection has been made,
the program asks the user to click on the position of the new isotope on
the chart of nuclides. The chart is automatically stored whenever the program
Calculations: calls the
Stable: selects a stable
decay: selects a b - emitter
decay: selects a b + emitter
and b + decay: selects a b-
and b + emitter (cyan).
selects an a emitter (green).
b and b+
decay: selects an a and b
+ emitter (orange).
Proton decay: selects a
direct proton emitter (purple).
Remove a nucleus: the program
asks the user to click on the nucleus which will be removed.
Read characteristics: not
Write characteristics: not
Calibrations: calls the
calibrations menu. The precision of the calibrations relies on the absolute
energy loss calculation precision which is around 2%.
Brho1, Brho2, Bwien: calculates
the Br of the two sections of the spectrometer
and the magnetic field of the Wien filter (if it has been enabled) for
the best transmission of the setting fragment. The current settings of
the spectrometer are updated to these new values. Clears previous calculations.
Brho charge state: calculates
the Br s and Wien magnetic field for any charge
state of any nucleus. Specially useful calculating the Br
s of the beam charge states. Can also be used to set the spectrometer on
a charge state different than the fully stripped fragment. Then one has
to record the calculated values and enter them manually via the command
Dipoles® Brho 1 or 2".
Transmission and rates:
calls the transmission and rates menu. The results of the calculations
are automatically updated on the chart of nuclides, showing the information
lines selected in the menu "Options® Display
1 or 2" for each fragment. If nothing appears after a calculation has been
done, it means that the rate of this particulary nucleus is below the threshold
(see also the "Options" menu).
One nucleus: the program
asks the user to click on the nucleus in the chart for which the calculation
will be performed.
Area of nuclei: the program
asks the user to click on the upper rightmost nucleus first, and then on
the lower leftmost nucleus second, in order to define the area of nuclei
All nuclei: the program
automatically starts the calculation for all nuclei displayed in the chart
from the projectile down to the lithium isotopes. Be aware that you can't
interrupt this command once it has been issued.
Goodies: calls the goodies
menu.® : clicking
on this arrow will open the menu used to select the spectrometer position
for which the following calculations will be performed. The default is
after the wedge.
After target: this selection
means that the calculations will be performed assuming the fragments have
a kinetic energy determined by the B( of the first section.
After wedge: with this selection,
the kinetic energy is taken after the energy loss in the wedge, not regarding
whether the fragment is actually transmitted by the second section or not.
That way, the calculations for the fragments which are not centered at
the first focus are more realistic than assuming that their kinetic energy
corresponds to the Br of second section, which
is only true at first approximation within the Br
Into material: in this case,
the kinetic energy is taken after the energy losses in the wedge and the
1st to (i-1)th material(s) where i is the number of the selected material.
This allows calculation, for instance, of the energy loss in a detector
after the fragments have been slowed down by some other material(s).
After material: same as
"Into material" but the energy loss into the ith material is included to
deduce the kinetic energy. Adds more flexibility to the calculational possibilities.
Energy and b
: asks the user to pick a nucleus of the chart and then calculates
its energy and b at the specified position.
Energy loss: calls the periodic
table menu to pick an element, and then asks for its thickness, and finally
the fragment for which the calculation has to be performed. If the position
"Into material \#i" is selected, the program only asks to pick a fragment
and calculates the energy loss in this material.
Energy straggling: displays
the energy straggling at the specified position after a fragment has been
Angular straggling: same
as for the energy straggling.
Range: same as in the energy
loss calculation but for the range.
Optimum target: asks the
user to pick a nucleus from the chart, and then starts to calculate and
draw the dependence of the production rate of this nucleus versus the target
thickness. For each step of target thickness, the program recalculates
the settings for the best transmission. One can clearly see the saturation
and then decrease of the production rate as the energy of the fragment
decreases and the straggling increase. The result are shown on the graphic
Wedge slope: calculates
the slope of an achromatic wedge in % of ¶ Br
Files: calls the files menu.
Beam energy from Br
1 and beam charge state: calculates the beam energy from Br
1, which has to be input manually, and its corresponding charge state.
This command is used during an experiment when one has centered a known
charge state of the beam at the intermediatefocal plane, and knows precisely
the thickness of the target (or doesn't have any target).
Target thickness from Br
1 and beam charge state: same as above, but this time the beam energy
is precisely known, and one wants to measure the thickness of the target.
Wedge thickness from Br
2 and nucleus: used to calibrate the thickness of the wedge during
an experiment, once a charge state or identified fragment has been centered
at the first focus. B(2 is then entered manually, and the program asks
the user which nucleus corresponds to this B( (and its charge state if
it is the projectile). The calculated thickness is the thickness seen on
the beam axis of the spectrometer.
Material \#i thickness for implantation
in \#j: This command is used to calculate the amount or material
\#i needed to implant a given nucleus at a given depth in \#j. \#i and
\#j are first specified by selecting `material' and `implantation in' respectively,
and then the program asks for which nucleus and at which depth the calculation
will be performed when selecting `thickness'. If the nucleus doesn't make
it through to the material \#j, the command is ignored. One can check easily
the average range by calculating the range after the material \#j-1 using
the command "Calculations® Goodies®
Plots: calls the plot menu.
Read: calls the directory
menu and asks the user to select a file to read. If the number of files
is greater than 50, a second page of files can be selected by clicking
on "Page". Going back to the previous page is just like going back to the
previous menu : move the mouse out of any selection and click. Once a file
has been selected, the program displays the title and asks for a confirmation.
Striking any key but "n" or "N" will be interpreted as yes. The screen
and internal parameters are then updated according to the file data.
Write: writes the current
settings and calculations to a specified file or a new file. If a filename
has been selected, the program asks for confirmation to overwrite it. If
it is a new file, the program prompts for a filename (the extension ".fic"
is automatically added) and a title.
Remove: erases the specified
file (with confirmation).
Results: creates or updates
a result file which has the same name as the current setting file, but
with the extension ".liz". This file is stored under the directory "\\RESULT"
and is automatically sent to the printer manager via the DOS command "Print"
whether one is installed or not (if it is not, the DOS will only issue
an error message, no big deal !). This file contains the parameters of
the spectrometer and the results of the transmission and rate calculations.
Spawn: this command is used
to copy the program to any other disk or directory. The program asks for
the DOS path corresponding to the destination, creates the needed directories,
and copies all the necessary files including this manual.
End: terminates the program
and returns to DOS. The chart of nuclides is automatically updated.
Table isotopes: this command
is used to browse through the chart of nuclides in order to look at different
areas of nuclei.
Plot (E-TOF: calls the identification
Go !: used to start the
plotting once all parameters are set to their correct values. Only the
fragments for which a transmission calculation has been performed will
appear on the screen. Once the plot has been completed, the mouse can be
moved to any nucleus to read its time of flight and energy loss, as well
as the corresponding channels on the actual spectrum if the calibrations
have been entered (see the following). The time of flight axis is reversed
as in most experiments in which the start detector has a much greater counting
rate than the stop detector. Reversing start and stop therefore prevents
starting the TAC or TDC without stopping it.
Detector: selects which
material will be used to calculate the energy loss.
TOF calibration (ns): once
the identification has been made, one can calculate a calibration of the
time of flight. Using this calibration, the program displays the channel
number on the horizontal axis.
(E calibration (MeV): same
as for the energy loss.
Length start ®
wedge: flight base length between start detector (target if the
HF of a cyclotron is used) and wedge.
Length wedge ®
stop: flight base length between wedge and stop detector.
Start of TOF: toggles between
"Detector" (the default) and "RF" for the start of the time of flight measurement.
In case "RF" is selected, the plot shows the wrap around due to the periodicity
of the cyclotron radiofrequency.
RF frequency: used to input
the radiofrequency of the cyclotron.
whether the identification of the plotted nuclei is directly displayed
on the screen or not. This option has to be turned off in case a lot of
nuclei are being displayed, in which case all the characters are overlapping
and it becomes very difficult to distinguish one isotope from the other.
In both cases (identification on or off), the nature of the nuclei is displayed
whenever the mouse is moved on them.
Threshold: one can set a
display threshold corresponding to the rate below which the nuclei are
E-E: plots a d E-E spectrum using the
parameters set for the d E-TOF spectrum.
Angular distributions: displays
the angular distributions (q and f
after both target and wedge) for the setting fragment and the most intense
contaminants. The different angular acceptances as well as the angular
transmission for each fragment are shown on the plot. The distributions
plotted are ¶ s ¤¶W
as a function of q (or f
). They can be drawn on a linear or log scale, and their total number is
fixed (see the two last selections of the Plot menu).
plot: displays the distributions at the intermediate focal plane,
where the Br selection occurs. The momentum
acceptance of the spectrometer is also shown. Same display comments apply
as for the angular distributions.
Wedge selection plot: displays
the distributions at the first focus, where the images corresponding to
different nuclei are selected by the slits at this position. Same display
possibities as for the angular distributions.
Wien selection plot: displays
the distributions at the second focus, which is the dispersive focal plane
of the Wien filter. Only valid if the Wien filter has been enabled. Same
display possibilities as for the angular distributions.
Range distributions: the
program asks the user first in which material these distributions should
be drawn. Then it displays the range distributions for the fragments which
actually stop in this material. These distributions are only drawn on a
Display: toggles between
"lin" and "log" for the display of the distributions. The default is "lin".
Number of distributions:
selects how many distributions will be drawn on the plots. The program
always starts with the distributions of the selected fragment, and then
adds the most intense contaminants. Only the nuclei for which a transmission
and rate calculation has been performed will be displayed.
5. Tutorial : a sample calculation
The following lines describe an example of a calculation
performed for a 84Kr beam at 60 MeV/u fragmented on a Be target
in order to produce 68Co. Although it does not explore all the
possibilities of the program, this example tries to exhibit most of its
different features. The calculations performed in this example are stored
in three different files "example1", "example2" and "example3" provided
with the diskette. Each correspond to a further cleaning of the 68Co
secondary beam using different selection criteria.The first step when starting
from scratch is to set the projectile, target and the secondary beam.
The above actions provide the minimum information required
to calculate the settings of the spectrometer and the transmissions. The
following lines describe an example of these calculations.
Start the program by typing "LISE".
Click on either "Previous menu" or "Main menu" to open
the main menu.
Select the "Setting" submenu by moving the mouse on it
until it is high-lighted, and then click.
Select the "Projectile" submenu.
Select the option "Nature, mass and charge". The program
then asks to choose the projectile from the chart of nuclides. The default
projectile being 40Ar, it flashes red at the middle of the screen.
Move the mouse to the right side until it changes to an arrow and then
click to scroll the chart to the left. Scroll down the chart by moving
the mouse to the top and clicking until you see the Krypton isotopes appearing.
Once you see 84Kr on the screen, move the mouse at its position
and click to select it. Then the program asks to enter successively the
ionic charge, energy and intensity. Enter the numbers 25 for the charge,
60 for the energy and 200 for the intensity using the numeric keypad (it's
easier) and "Enter". Once all of this has been done, the information related
to the projectile is displayed in red on the right side of the screen,
and 84Kr flashes red on the chart of nuclides. The program displays
back the bar "Previous menu?Main menu". Click on "Previous menu" (the default
position of the mouse) to recall the projectile submenu.
Since all information related to the projectile has been
entered, go back to the setting menu by clicking once the smiling face
appears (it automatically appears on top of the submenu when "Previous
menu" has been selected).
Select the target submenu.
Select the option "Nature". The program displays the
periodic table submenu. Move the mouse to "Be" until it appears high-lighted
and click. The target element is then displayed in green on the right side
of the screen. Enter the target thickness (100 mg/cm2) and go
back to the previous submenu depth (select "Previous menu").
To return to the setting submenu, click to go back to
the target submenu, then move the mouse out of the "Nature" selection (the
smiling face should reappear) and click.
Scroll down to the "Setting fragment" selection and click.
As for the choice of the projectile, scroll the chart of nuclides until
appears, then click on it.
Return to the Setting submenu using "Previous menu",
and select the Spectrometer submenu.
Select "Slits" and then "Slits intermediate focal plane".
Enter the opening of the slits (enter ±15 mm). This value appears on the
right side of the screen followed by corresponding momentum acceptance
The program predicts a production rate of 28 68Co
per second for a beam intensity of 200 enA. It is now possible to determine
which other fragments are transmitted with the 68Co. Let's first
set the rate threshold at one count per minute since we are only concerned
by the fragments having a larger production rate.
Select the "Calculations" submenu from the main menu.
Select the "Brho1, Brho2, Bwien" option. The program
starts to calculate the field settings of the spectrometer. It first calculates
the range tables of Krypton and Cobalt in Beryllium (a flashing box appears
on the screen for each energy). Once these tables are calculated, they
are automatically stored on the disk (see 3.4.). Then the B( of the two
sections of the spectrometer as well as the corresponding magnetic fields
are displayed on the right side of the screen.
Click on "Previous menu" to return to the calculation
Select the "Transmission and rate" submenu.
Choose the "One nucleus" option. Select the 68Co
from the chart. The program then calculates and displays two numbers :
11.60 % which is the total transmission (first line of information by default),
and 2.8e+01 which an estimation of the rate in pps (second line of information
Let's now assume that there is a silicon detector at
the focal point of the spectrometer. Measuring the energy loss and time
of flight of each particle allow to identify them. The plot generated by
LISE tries to reproduce the actual bidimensionnal spectrum observed during
the experiment. Establishing the correspondance between these two spectra
allows to identify the nuclei and get a calibration of both energy loss
and time of flight.
Select "Main menu® Settings®
Select "Calculation thres." in the Options submenu. The
cursor appears in the submenu. Enter the number 1.67e-2. To verify that
this value has been effectively taken into account, select "Previous menu"
: the value displayed for the calculation threshold is now 1.7e-02. Only
the format of the number has been changed, and the value in memory is still
Go back to the main menu using the smiling face, and
select "Calculation® Transmission and rate®
All nuclei". The program will calculate the rate for all possible fragments,
starting from the projectile with fewer neutrons, down to the Lithium isotopes.
During this process, it will calculate and store the range tables of all
these elements in Beryllium (except for Cobalt which has already been calculated).
All this may take a while (depending on the computer speed) and cannot
be interrupted but by a reset of the system, so it's probably time for
coffee break !
For each nucleus transmitted at a rate larger than one
per minute, the program displays the total transmission in % and the rate
in pps. A lot of nuclei are transmitted together with the 68Co
because the only selection used is the Br selection
of the first section of the spectrometer.
Select "Main menu® Settings®
Angular transmission". The first line of information now displays the angular
transmission (or geometrical transmission due to the ( and ( acceptances
after the target and the wedge positions). It is possible to display any
of the informations listed in the Display1 or 2 submenu.
Select "Main menu® Plots®
Table isotopes".Browse through the chart of nuclides in order to look at
different regions of transmitted nuclei. Click on any nucleus to return
to the menu.
The second step in the purification of the 68Co
beam is performed by the selection of the second section of the spectrometer
when an achromatic wedge is inserted at the intermediate dispersive focal
plane. Due to their different energy losses in the wedge, different nuclei
are focused at different positions at the focal point of the spectrometer,
where the opening of the slits determines the transmission.
Select "Main menu® Settings®
Options® Thickness unit". This command toggles
the thickness unit to (m.
Go back to the Settings submenu and select "Material(s) ®
Material \#1® Add® Si". Then enter the thickness in m m (enter
100 m m).
Select "Main menu® Plots®
Plot d E-TOF® Detector".
Enter the material number of the detector used to measure the energy loss
(this is obviously 1).
Return to the Plot d E-TOF
submenu and toggle the Identification off. This is to prevent having the
names of the nuclei plotted on the screen, in the case too many of them
are overlapping and therefore impossible to read.
Select "Go !". This will start generating the plot. The
screen stays erased until the energy loss calculations are performed. If
the range tables of elements Krypton through Lithium into Silicon are not
yet calculated, the program will generate them and store them on disk (this
might take a little more time). Once the plot is produced, the mouse appears
as a cross. The name, transmission and rate of any nucleus appears on the
right side of the screen whenever the cross is pointing on it. One can
clearly see the isospin lines on the plot (the most obvious one is the
N=Z straight line), as well as the tilted Z lines which flatten for the
lighter elements. To return to the menu, click anywhere and strike any
Select "Main menu® Settings®
Options® Thickness unit" to toggle back to mg/cm2.
Select "Previous menu® go
back® Wedge® Nature®
Al" and enter the thickness of the wedge (50 mg/cm2). As soon
as this entry is made, the calculations are cleared.
Select "Previous menu® go
back® go back® Spectrometer®
Slits® Slits image1' and enter ±2 mm. This opening
determines the selectivity of the second section of the specttrometer when
a wedge is used
Select "Main menu® Calculations®
Brho1, Brho2, Bwien" to calculate the new settings of the spectrometer
corresponding to the best transmission for 68Co.
Select "Previous menu® go
back® Transmission and rate®
area of nuclei" and click on 74Ga first (the upper rightmost
nucleus) and then on 63Cr (the lower leftmost nucleus). This
will start the calculation only for the nuclei located in the square defined
by 74Ga and 63Cr. Since a lot few nuclei are being
transmitted, it is not necessary to calculate the transmission for all
Just by looking at the (E-TOF spectrum obtained with
the wedge, it is possible to tell what selection a velocity filter will
provide. The cut in velocity will correspond to a cut in TOF centered around
It will therefore be possible to reduce the amount of
using a Wien filter.
The insertion of an achromatic wedge has considerably
reduced the amount of nuclei transmitted with the 68Co. This
additional selection can be visualized by looking again at the d E-TOF plot.
Select "Main menu® Plots®
Plot d E-TOF® Identification'
to toggle the identification back on.
Select "Previous menu® Go
!" to start the plot. In an actual experiment, one would use the calibration
determined from the previous plot to identify the nuclei on the experimental
spectrum. If this calibration is entered in the Plot d E-TOF submenu, the numbers labelled "Ch\# X" and "Ch\# Y" give the channel
numbers corresponding to the position of the mouse.
One can also visualize the selection performed by the
wedge and the second section of the spectrometer by plotting the position
of the images corresponding to different nuclei at the first focal point.
Select "Previous menu® go back®
Wedge selection plot". The images are spread along the horizontal axis,
being centered with respect to the slits. It is interesting to notice that
the image of 71Cu is also rather well centered, therefore it
is impossible to get rid of it using the wedge technique. Another selection
criteria such as the one provided by a Wien filter (velocity filter) has
to be used.
6. Computer considerations
Select "Main menu® Settings®
Options® Wien filter" to enable its use in the
calculations. This command clears the previous calculations.
Select "Previous menu® go
Wien filter® Electric field" and enter a value
of 3000 kV/m. The magnetic field setting of the Wien filter is then automatically
calculated for the best transmission of 68Co, as well as the
dispersion. All these informations appear on the right side of the screen.
Select "Previous menu® go
back® Slits® Slits
second image" and enter an opening of ±2 mm.
Do the calculations of the rates (select "Main menu®
Calculations® Transmission and rate®
Area of nuclei" and click on 74Ga then on 63Cr).
The amount of 71Cu is greatly reduced and 68Co is
now the main component of the beam. However, 70NiBis still present
at a competitive rate.
Select "Main menu® Plots®
Wien selection plot" to plot the distributions at the second focal point.
It then becomes obvious that although the Wien filter is efficient to get
rid of 71Cu, it can't do the same for 70Ni because
its velocity is close to that of 68Co.
Select "Previous menu ® Wedge
selection plot" to look again at the selection provided by the wedge. 70Ni
appears to be shifted from the slits position. Two solutions are possible
to reduce further its contamination of the beam : one can close the slits
of the first image further, although this will also decrease the amount
of 68Co transmitted, or one can also increase the thickness
of the wedge in order to shift the image of 70Ni further to
the left. This last solution appears to be the best. However it ought to
be tested, since a thicker wedge will cause a broadening of the images
and an increase the angular scattering, resulting in a loss in the transmission
LISE is a DOS-based software running on any IBM compatible
PC. It runs under DOS 3.1 and following versions, and only needs 640 kbytes
of memory. The speed of the program depends greatly on the CPU type, speed
and configuration. The use of a co-processor is greatly recommended : the
program uses FFT (Fast Fourier Transform) algorithms which contain extensive
floating-point operations.The last version has been developed on a 386-SX
at 16 MHz with a co-processor which provides a reasonable speed (about
1 second per transmission calculation). Trying the program on a 486-based
system showed a great improvement (it was impossible to measure the time
lapse of the same calculation !).The program uses a mouse driver loaded
at the start-up of the computer. This driver has to be Microsoft compatible
(most of them are). The graphics interface included with the program (file
"EGAVGA.BGI") insures the compatibility with any EGA or VGA compatible
graphic card. The program looks automatically for the best resolution the
card can provide (although it is limited to the maximum standard VGA resolution
640x480x16 colors). The hardcopy of the graphic screen can be made on a
printer provided the command "graphics" is executed at start-up.The first
version of LISE has been written in 1987, using the Borland Turbo C compiler.
It is written in C for several reasons : it is one of the few languages
that allow piloting the mouse driver directly via software interrupts,
in order to create one's own menu system. Also, Turbo C provides an extensive
number of graphic routines, and finally recursivity, the ability to manipulate
data structures, and the possibility to allocate and deallocate memory
dynamically are a major improvement in programming. Today, the C language
has evolved even further towards Object Oriented Programming, producing
the C++. Following this evolution, the latest parts of LISE are written
in C++. Portability is always a critical issue in programming, and C++
is certainly one of the best suited language for this task. However, this
software is still tightly bound to MS-DOS, and its transfer to other machines
running under different systems would require a non negligible amount of
time and has not yet been done.
 K. Sümmerer et al., Phys. Rev. C 42 (1990) 2546-2561.
 J.P. Dufour et al., Nucl. Instr. and Meth. A248
 F. Hubert et al., Atom. Dat. and Nucl. Dat. Tabl.
46 (1990) 1-213.
 L.C. Northcliffe and al., Nucl. Dat. Tabl. A7