Reduced transition probability calculator - because no one else made a simple command line calculator for this.
Maintainer: Jonathan Williams
Use make to compile. To run the program from anywhere, move the resulting bcalc executable to any directory under your $PATH environment variable.
This shouldn't depend on any external libraries. Tested on CentOS 7 and Arch Linux (as of February 2024).
The calculator is run from the command line, for example:
bcalc -e VALUE -m VALUE -lt VALUE
Running bcalc without any parameters will print a list of parameters.
Both of the following are needed:
| Parameter | Description |
|---|---|
| -e | transition energy in keV |
| -m | multipole (eg. E1, M1, E2, etc.) |
One of the following is needed:
| Parameter | Description |
|---|---|
| -lt | Mean transition lifetime (in ps, use -ltns / -ltus / -lts / -lth for nanoseconds / microseconds / seconds / hours, respectively). |
| -hl | Transition half-life (in ps, use -hlns / -hlus / -hls / -hlh for nanoseconds / microseconds / seconds / hours, respectively). |
| -b | Reduced transition probability (for the L multipole) in units of e^2 fm^(2L) for electric multipoles or uN^2 fm^(2L-2) for magnetic multipoles. |
Optional parameters:
| Parameter | Description |
|---|---|
| -br | branching fraction of this transition (maximum 1, default 1) |
| -d | mixing ratio with the L+1 multipole |
| -icc | internal conversion coefficient for this transition (default 0) |
| -ji | inital spin (integer or half-integer) |
| -jf | final spin (integer or half-integer) |
| -A | mass number of the nucleus |
| -Z | proton number of the nucleus |
Flags:
| Flag | Description |
|---|---|
| --barn | Use/calculate transition probability with spatial dimension in barns rather than fm (eg. B(E2) in e2 b2 rather than e2 fm4). |
| --wu | Use/calculate transition probability in Weisskopf units (W.u.) rather than the default units specified above. If used, requires the -A parameter. |
| --up | Use/calculate transition probability from final to initial state instead of vice versa. If used, requires the -ji and -jf parameters. |
| --brrel | Specifies that the branching fraction provided with the -br option is actually an intensity relative to another transition. |
| --beta2 | Calculate the quadrupole deformation parameter, assuming a 2->0 (g.s.) E2 transition. Requires -m E2 -ji 2 -jf 0, and the -A and -Z parameters. Assumes mean charge radius R = r_0*A^(1/3), with r_0 = 1.2 fm. |
| --quiet | Only show the result of the calculation. |
| --help | Print a list of parameters. |