FRIB Estimated Rates
The projected intensities of beams at FRIB are online at
Some tools for COSY and LISE++ from Mauricio Portillo
* COSY to MOCADI map conversion and command builder
* COSY to LISE++ map conversion
* COSY generator of LISE++ extended type blocks
* Convert LISE++ Monte Carlo output to ROOT ntuple
Transport Integral: A method to calculate the time evolution
of phase-space distributions
D.Bazin and B.M.Sherrill, Physical Review E, vol.50 (5), 1994, pp.4017-4021.
An analytical technique using integral equations for
the transport of ion-optical intensity distributions through magnetic systems
is described. It can serve as an alternative to Monte Carlo simulation to
calculate the time evolution of phase-space distributions of any given shape.
Under the assumption of linear optics, the solution of the integral equations
can be reduced to convolution products. One major application of this
approach is the fast calculation of the transmission and purification of
radioactive nuclear beams produced by projectile fragmentation.
Application to fusion-evaporation: LisFus & PACE4
O.B.Tarasov, D.Bazin, NIM B204 (2003) 174-178
A new fusion-evaporation model LisFus
for fast calculation of fusion residue cross sections has been developed in
the framework of the code LISE.
This model can calculate very small cross-sections quickly due to its compared
to programs using the Monte Carlo method. Such type of fast calculations is
necessary to estimate fusion residue yields. Using this model the program
LISE has now the possibility to calculate the transmission of fusion residues
through a fragment separator.
is also possible to use fusion residues cross sections calculated by the
which has been incorporated in the LISE package. The code PACE is a modified version of JULIAN
- the Hillman-Eyal evaporation code using a Monte-Carlo code coupling angular
momentum. A comparison between PACE and the
LisFus model is presented.
NIM B204 (2003) 174-178
of momentum distribution of
projectile fragmentation products
Fragment momentum distributions measured in relativistic heavy ion
collisions are typically observed to be gaussian shaped. Within the framework of the well-known statistical model
, a parabolic dependence
of the width of the gaussian momentum distributions is obtained, and the fragment velocity is equal the projectile velocity.
However, this model is unable to account for the following:
* The differences in widths associated with nuclides of the same mass;
* The apparently anomalously small values of s0 observed at lower energies;
* The occurrence an exponential tail in momentum distributions in reactions at low energies;
* The reduction of the velocity relation of a fragment to projectile at low energies.
Different models were developed further for an explanation of these phenomena both theoretical, and empirical parameterizations. Each of
models has advantages and drawbacks depending on energy, mass of projectile and other parameters. The universal parameterization, which avoids the indicated drawbacks inherent in the statistical
model is developed and adapted in the LISE program.
This model of momentum distribution is universal: it includes a definition of the distribution width depending on beam energy and
on prefragment excitation energy, an estimation of the most probable fragment velocity, and a low-energetic exponential tail. An attempt to describe experimental distributions of fragmentation products was undertaken
using a convolution between gaussian and exponential lineshapes.
NNC 2003, Moscow.
PowerPoint (3.8 MB)
A734 (2004) 536-540
Statistical model calculations in heavy ion reactions (PACE)
A.Gavron, Phys.Rev. C21 (1980) 230-236
Results of various fusion experiments with heavy ions are compared with
predictions model calcualtions (PACE). In some reactions there is evidence for
nonstatistical effects based on significant discrepancies between the
calculations and the experimental results. Alternative explanations of these
discrepancies are considered.
Calculated Nuclide Production Yields in Relativistic Collisions of Fissile Nuclei
J.Benlliure, A.Grewe, M.de Jong, K.-H.Schmidt, S.Zhdanov
Nucl.Phys. A628, 458 (1998)
A model calculation is presented which predicts the complex nuclide distribution resulting from peripheral relativistic heavy-ion collisions involving fissile nuclei. The model is based on a modern version of the abrasion-ablation model which describes the formation of excited prefragments due to the nuclear collisions and their consecutive decay. The competition between the evaporation of different light particles and fission is computed with an evaporation code which takes dissipative effects and the emission of intermediate-mass fragments into account. The nuclide distribution resulting from fission processes is treated by a semi-empirical description which includes the excitation-energy dependent influence of nuclear shell effects and pairing correlatios. The calculations of collisions between 238U and different reaction partners reveal that a huge number of isotopes of all elements up to uranium is produced. The complex nuclide distribution shows the characteristics of fragmentation, mass-asymmetric low-energy fission and mass-symmetric high-energy fission. The yields of the different components for different reaction partners are studied. Consequences for technical applications are discussed.
A Reexamination of the Abrasion-Ablation Model for
Description of the Nuclear Fragmentation Reaction
J.-J.Gaimard, K.-H.Schmidt, Nucl.Phys. A531, 709 (1991)
The nuclear fragmentation reaction is studied as an important production
mechanism for secondary beams. The geometrical abrasion model and a
macroscopic evaporation model which describe the two steps of the reaction are
reexamined. Several improvements and modifications of these models are
discussed and a new model description incorporating these elements is
proposed. In particular, the excitation energy and the angular-momentum
distribution of the prefragments, the formulation of evaporation as a
diffusion process and the role of microscopic structure in the production
cross section are considered. The new model description preserves the
simplicity and the transparency of the original models. The prediction of the
new model are compared to those of the original models and to experimental
cross sections. While the original models showed several systematic
discrepancies in comparison to measured cross sections, the new model is able
to reproduce the whole body of experimental data with satisfactory agreement.
Modified Empirical Parametrization of Fragmentation Cross Section
K.Summerer, B.Blank, Phys.Rev. C61, 034607 (2000)
New experimental data obtained mainly at the GSI/FRS facility
allow one to modify the empirical parametrization
of fragmentation cross sections. It will be shown that minor
modifications of the parameters lead to
a much better reproduction of measured cross sections. The
most significant changes refer to the description of
fragmentation yields close to the projectile and of the memory
effect of neutron-deficient projectiles.
ATIMA is a user program developed at GSI which calculates various
physical quantities characterizing the slowing-down of protons and heavy ions
in matter for specific kinetic energies ranging from 1 keV/u to 500 GeV/u such
- stopping power
- energy loss
- energy-loss straggling
- angular straggling
- range straggling
- beam parameters (magnetic rigidity, time-of-flight, velocity, etc.)
- atomic charge-changing cross sections
- charge-state evolutions
- equilibrium charge-state distributions
Charge states of relativistic heavy ions in matter
C.Scheidenberger, Th.Stohlker, W.E.Meyerhof, H.Geissel,
P.H. Mokler, B. Blank, NIM B142 (1998) 441-462.
Experimental and theoretical results on charge-exchange
cross-sections and charge-state distributions of relativistic
heavy ions penetrating through matter are presented. The data
were taken at the Lawrence Berkeley Laboratory's
BEVALAC accelerator and at the heavy-ion synchrotron SIS of
GSI in Darmstadt in the energy range 80±1000
MeV/u. Beams from Xe to U impinging on solid and gaseous
targets between Be and U were used. Theoretical models
for the charge-state evolution inside matter for a given
initial charge state are presented. For this purpose, computer
codes have been developed, which are briefly described.
Examples are given which show the successes and limitations
of the models.
Charged particle transport code
1. K.L. Brown, D.C. Carey, Ch. Iselin and F. Rothacker:
Transport, a Computer Program for Designing Charged Particle Beam Transport
Systems. CERN 73-16 (1973) & CERN 80-04 (1980).
2. Urs Rohrer,
Compendium of Transport Enhancements
Particle interaction with matter
The Stopping and Range of Ions in Matter (SRIM)
SRIM is a
group of programs which calculate the stopping and range of ions (up to 2
GeV/amu) into matter using a quantum mechanical treatment of ion-atom
collisions (assuming a moving atom as an "ion", and all
target atoms as "atoms"). This calculation is made very
efficient by the use of statistical algorithms which allow the ion to make
jumps between calculated collisions and then averaging the collision results
over the intervening gap. During the collisions, the ion and atom have a
screened Coulomb collision, including exchange and correlation interactions
between the overlapping electron shells. The ion has long range interactions
creating electron excitations and plasmons within the target. These are
described by including a description of the target's collective electronic
structure and interatomic bond structure when the calculation is setup (tables
of nominal values are supplied). The charge state of the ion within the target
is described using the concept of effective charge, which includes a velocity
dependent charge state and long range screening due to the collective electron
sea of the target.