1. Reduction of a fragment output due to reactions

1. Reduction of a fragment output due to reactions

In the new version of the program losses from reactions in a target, a stripper and a wedge, and also contributions of secondary reactions to outputs of fragments are more accurately investigated. In the previous versions simple dependence of formation of reactions products that is true in a case only thin targets was assumed:

,     /1/

1.1. Reactions in a target (stripper)

As the target thickness is increased, the probabilities of destroying the fragment of interest and the projectile become significant. These probabilities are governed by the total cross sections of the fragment s_F and accordingly the projectile s_P. Taking this into account, the number of fragments F is determined as:

   .      /2/

   .      /3/

1.2. Reactions in a wedge

In the new version of the program losses of number of fragments due to responses in a wedge also are taken into account. The new coefficient 23 showing the ratio of lost fragments to a total number got in a wedge (x is its thickness) is entered .

Fig.1.

1.3. Reactions in materials

The user also can see the considering of reactions in materials in dialogue "GOODIES" which represented on Fig.2. It is possible to observe as loss in the given material (À), and how many percent of fragments has remained from a beginning number got in a telescope.

2. Calculation of the secondary reactions contribution in a fragment output

In version 4.7 the user only could make the plot of the contribution of secondary reactions for one fragment. In the new version Possibility to take into account the contribution of secondary reactions for all selected products of projectile fragmentation has appeared directly at calculation of transmission. To apply the calculation of secondary responses it is necessary to include an appropriate option (A) in menu PREFERENCES (see Fig.3).

In the mode of the calculation of secondary reactions in an upper right corner of SETTINGS window the green flag SEC will appear (see Fig.4). The number under this flag designates quantity of fragments involved for calculation of the secondary reaction contribution.

Fig.4. Flag of secondary reaction calculations is set.

Allocations of fragment outputs after a target depending on target thickness are kept in memory. They are deleted, if thickness of a target or has decreased in 5 times, or has increased in 2 times and also if the energy of an initial beam has varied on 10 percents. If new thickness of a target satisfies to the above-stated conditions an output of fragments are interpolated from the saved arrays. When the user sets area of nuclei (F_top,right , F_bottom,left) for transmission calculation, the program determines new square for calculation of secondary reactions in view of that the projectile (P) also should enter into this area, and then expands the given square on one unit in all sides:

  ,     /4/

For the registration of the secondary reaction contribution the new coefficient of transmission at number 24 is entered. The algorithm of calculation of the secondary reaction contribution also counts losses of outputs in a target and in a stripper. However and the coefficient 22 (look the previous paragraph) takes into account it. To avoid the repeated registration of losses thanking responses in targets, coefficient 24 it is written as follows:

2.1. Secondary reactions and Optimal target calculations subroutine

The new version of the program also allows to take into account the contribution of secondary responses at calculation of an optimal target thickness. If the energy of an initial beam is more 200 AMeV or the option "Secondary Reactions" is set, the program will offer automatically to calculate thickness in view of secondary reactions. The user has possibility to disable the given option (see Fig.5). For matching on a graphics outputs of a fragment are shown depending on target thickness as well as in view of secondary responses, and without them (see Fig.6).

3. Other

3.1. New generator of random numbers

In the new version of the program the generator random numbers was replaced on more advanced. A range of the new generator up to 2³²-1, that best allows to feign bidimensional plots in a mode of Monte Carlo acquisition. The reference to generators of random numbers: http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf/c7-0.pdf

3.2. Creation of a file with results of secondary reactions contribution

Using the plot "Output of products from a target with the contribution of secondary reactions" through the menu "Utilities", the user can get access to a file of results of calculations of fragments outputs in view of the contribution of secondary reactions (see Fig.7). The given file is in root directory LISE and called "contribution.txt".

The given file allows to see what fragments give the greater contribution through secondary reactions in a fragment of interest and also to analyze a difference between fragments outputs without amendments on the basis of the formula /1/ with outputs in view of secondary reactions. Whence it is possible to draw a conclusion on an example what fragments has advantage at relativistic energies with use of a thick target.

The example of the given file for a fragment ³¹F gives below:

Pressing the left key of a mouse on dialogue About, the user automatically causes a brouser and loads the homepage of program LISE located to the address: http://http:"//lise.nscl.msu.edu. In the following versions it is planned to make automatic check on presence of the new version of program LISE on the appropriate servers, and also access through the INTERNET to various bases to the data (on an example on a database of isomers to the address: http://www.ganil.fr/LISE/isom.html)

3.4. Angles of an inclination of a target and a stripper

In the new version the user can establish in the menu "Preferences" (see Fig.3, ellipse B) an option of simultaneous turn of a target and stripper, taking place for a target. If the user has changed an angle of an inclination of a target automatically there will be a change of an inclination of a stripper, and the user will receive the message on it. If this option is established, Optimum thickness of a target from an inclination of a target will be calculated also under condition of a simultaneous inclination of a target with a stripper (see the following paragraph).

3.5. Calculation of optimal target thickness from an inclination of a target

In the new version the user can calculate an optimum corner of an inclination of a target (simultaneously with a stripper and without it: see above). Through menu "Calculations" (Fig.8) it is possible to call the given utility. For calculation initial thickness of detectors are accepted at an inclination in 0 degrees. This procedure works can work also with options "Secondary reactions" and "Charge states". The example of calculations is given in figure 9.

3.6. File of transmission calculation results

In a file of transmission calculation results the angles of an inclination of a target (stripper, wedge, materials) and according to their thickness under zero of degrees now are deduced. The factor K (equation /6/), showing change of an output of fragments due to reactions in a target (stripper, wedge) also is added.