Maintainer: Jonathan Williams
Calculates the directional distribution for gamma radiation emitted from an axially symmetric oriented source. Based on code written for the g77 compiler by K. Starosta to calculate gamma-gamma angular correlations.
Use make to compile. To run the program from anywhere, move the resulting ang_dist executable to any directory under your $PATH environment variable.
This shouldn't depend on any external libraries, just the gfortran compiler. Tested and seems to work on Ubuntu 14.04/16.04, Scientific Linux 6, and CentOS 7.
The program can be run using command line argments or using an interactive prompt. to use the interactive prompt, run the program without any arguments:
./ang_dist
Running the program in this way also prints out the syntax used to run the program with command line arguments, which is:
./ang_dist I_final I_init L delta sigmaj q2 q4 q6
Only the first 3 argments (I_final, I_init, L) are required - omitting later argments will cause default values to be used instead. The argument list is described in the following table:
| Argument | Description |
|---|---|
| I_final | Final spin of the electromagnetic transition. |
| I_init | Initial spin of the electromagnetic transition. |
| L | Multipolarity (1=dipole, 2=quadrupole, etc.) of the electromagnetic transition. |
| delta | The mixing ratio with the L+1 multipole (L+1/L ratio, 0 for no mixing). Default value: 0 |
| sigmaj | De-orientation parameter specifying the width of the initial distribution of magnetic sub-states. Default value: 0 |
| q2 | Attenuation factor (multiplicative coefficient) for the 2nd order Legendre polynomial term. Default value: 1 |
| q4 | Attenuation factor (multiplicative coefficient) for the 4th order Legendre polynomial term. Default value: 1 |
| q6 | Attenuation factor (multiplicative coefficient) for the 6th order Legendre polynomial term. Default value: 1 |
If all arguments are specified and an extra argument (of any value) is added at the end, this causes the program to run in a mode where only the a0, a2, a4, etc. coefficents are reported, which is useful for interfacing with scripts.
- K. Starosta (original codebase)
- J. Williams (more features, port to
gfortran) - This code uses components of the CERNLIB math library, which are provided in the cernlib directory of this repo under their original license.
- W.D Hamilton et al., 'The Electromagnetic Interaction in Nuclear Spectroscopy', particularly eq. 12.197
- used -std=legacy flag to supress warnings
- used -ffixed-line-length-none to avoid errors caused by lines that go over the default 72 character limit