Software

This page describes codes written in Java by Dale Visser for use in simulating and analyzing experiments on the Enge Split-Pole spectrometer. A page describing the older codes on which they were based is here.

The .class files, .java files, and additional needed data files are all packaged in dwvisser.jar. Download the code and startup scripts here.

• JRelKin - Java-based RELativistic KINematics 
• SPANC - SplitPole ANalysis Code 
• Plotter - simulates position spectra for different reactions 
• Det - focal plane detector simulation program 

To run any of the these programs while at WNSL, login to the astro account on meitner.physics.yale.edu from any x-terminal. Each individual program has instructions for running it below.

JRelKin

Install it on your computer.

• Enter this to run from the astro account: jrelkin

The relativistic kinematics program RELKIN was written by former graduate students to calculate reaction kinematics parameters of interest to SplitPole users. The older Fortran version is a little more flexible. It can handle gamma-rays in the incoming or outgoing channels as well. It can be run from the astro account by entering relkin from the shell.

RELKIN has been updated to Java, given a graphical interface, and called JRelKin. In the program, the user enters beam, target, and projectile nuclei in the table at the top. The residual nucleus is determined automatically, and Q0, the ground-state Q-value is displayed. If QO is negative, it represents the amount of energy needed in the center-of-mass system for this reaction to occur.

Single or multiple beam energies, residual excitations, and spectrometer angles may be entered. For each, 3 options are given: Single Value, Range, or Many Values. For One Value, just enter a single value in the text field. For Range, enter a start value, max value, and step value separated by spaces. For Many Values, enter as many values as you like, separated by spaces. For all entries, hitting enter causes the change, and JRelKin automatically recalculates and updates the table. Additionally, there is a target thickness field, which will cause the beam energy, projectile kinetic energy, and projectile QBrho values to be modified for energy losses. The target is assumed to be made entirely of the same element as the target nuclide.

The column headings in the JRelKin results table are as follows:

T(1)

Kinetic energy in MeV of the beam in the lab system. If a non-zero target thickness is given, this is the beam energy at halfway through the target.

Ex(4)

Excitation energy of the residual nucleus in MeV.

Lab Deg(3)

Angle in degrees of the projectile in the lab system.

CM Deg(3)

Angle in degrees of the projectile in the center-of-mass system.

T(3)

Kinetic energy in MeV of the projectile in the lab system. If a non-zero target thickness is given, this is the kinetic energy after traversing the remainder of the target.

Lab Deg(4)

Angle in degrees of the residual in the lab system.

T(4)

Kinetic energy in MeV of the residual in the lab system.

Jac(3)

The Jacobian for the projectile for transforming between the lab and center-of-mass systems.

k(3)

Kinematic shift parameter for determining the position of the focal plane of the spectrometer. k=1/p * dp/dTheta for the projectile.

z

Only useful at WNSL. Our digital readout for the detector position will read this value for the detector sitting properly at the focal plane. See the page on SplitPole setup

.

QBrho(3)

Magnetic rigidity in e-kG-cm of the projectile in the lab system. This value is derived directly from T(3), and so is also affected by finite target thickness.

Back to top.

Spanc

Install it on your computer.

• Enter this to run from the astro account: spanc

See the manual ([HTML] [pdf]) for more information.

Back to top.

Plotter

Install it on your computer.

• Enter this to run from the astro account: plotter [input file]

This code will plot position spectra on the focal plane detector for multiple reaction channels. You must specify the name of an input file when you launch it. A sample input file is here: 35MeV_10B_t.inp. Excitation energies for the residual nucleus are automatically loaded from a file called excitations.dat, which must be in the same directory as the input file. You may modify the files given here as needed. The format should be self-explanatory. You may specify as many reaction channels as you wish at the end of the .inp file.

Back to top.

Det

Install it on your computer.

• Enter this to run from the astro account: det [input file]

Det simulates particle ID on our focal plane detector. The program reads from the same format input file as Plotter. Det does not use a file with excitation energies. It just steps through arbitrary excitation energies to produce its output. Its output is a PAW command file, which must be processed by PAW to produce screen graphics and a postscript file.

Back to top.

Data Acquisition Software

The data acquisition program we have created and use is Jam.

Back to top.

Nuclear Astrophysics Home