LISE++

East Lansing
09-JUN-2001

Contents:

1. Short review of the Kinematics Calculators in previous versions of the code

2. Kinematics Calculator

3. Miscellaneous

The purpose of these calculators is to help physicists quickly get visual information on various characteristics of nuclear reaction, in particular about the kinematics of the reaction products. In previous versions the following utilities for kinematics calculation were already available:

1. Version 4.0.30 — Reaction kinematics (two body) relativistic calculations
   lise_4_0_30.html
2. Version 4.13 - Scattering calculator
   lise_4_13.htm#g2

However users of the LISE program stated the following:

• Calculations of break-up reactions kinematics;
• Possibility to enter the excitation energy for the particle and the target in the Scattering calculator;
• Errors in the calculations of scattered particles rates in detectors (Scattering calculator) were noticed.

In the new version these utilities were incorporated in one unique "Kinematics Calculator", which includes all features from both calculators as well as new options.

The new "Kinematics Calculator" is available in the "Calculations" menu or via the icon in the toolbar. The "Kinematics Dialog" is shown in Fig.1. In this dialog the user can choose one from three types of reactions. For convenience all participants of the reaction are designated by letters and the possible types of reactions are shown.

New features:

1. The kinematics calculation of break-up reactions was added (see Fig.2). Note that for break-up reaction the Q-value has to be greater than zero! (otherwise the reaction will not occur);
2. Possibility to enter of the excitation energy of all participants;
3. Possibility to enter the parameters of beam and target directly from the dialog (in previous versions it was necessary to leave the dialog);
4. Possibility to use to use a detector system for break-up and two-body reactions also (before it was only for scattering). However it is necessary manually to set the differential cross-sections in these cases;
5. Some errors have been corrected.

Fig.1. Kinematics Calculator

In previous versions it was assumed, that the slits in dispersive and first focal planes were symmetric, whereas the slits after the velocity filter could establish could be moved independently. In the new version the user can get all horizontal slits independently (see Fig.3). To use this feature the user has to choose the mode "Separately" (compare "A" and "B" in Fig.3).

In the new version the user can increase or reduce (see A in Fig.4) the magnetic rigidity and magnetic field by percentage set by the user (B in Fig.4). The same feature exists now for all calibration dialogs as well.

The user can set the dimension of distributions of secondary reactions contributions in the OPTIONS menu > Preference. By increasing the dimension the user improves calculations quality, but loses in speed. The default value is set to the minimal value (16).

In the menu PLOT-> OPTIONS it is possible to set an accelerator radio-frequency fraction for dE-TOF plot. The default value is 1. NSCL scientists use for this kind of plots to prevent the folding of the time-of-flight on the spectrum with fraction equal to 2.