Source

GRAS uses the Geant4 General Particle Source (GPS) as its source generator for the primary particles. GPS offers many options for the choice of particle type, energy spectrum, emission point and emission direction distribution, with several useful predefined options and the possibility of user defined spectra. Source biasing is also part of GPS. A detailed documentation on the use of GPS can be found in 11.

Script example:

/gps/particle proton
/gps/ene/type Arb
/gps/hist/type arb

/gps/hist/point 1.0023 202.26
/gps/hist/point 1.0162 207.42
/gps/hist/point 1.0304 212.75
...
/gps/hist/point 97277 0.000065036
/gps/hist/point 98629 0.000062654
/gps/hist/point 100000 0.000060364
/gps/hist/inter Lin

/gps/pos/type Surface
/gps/pos/shape Sphere
/gps/pos/radius 0.5 m
/gps/pos/centre 0. 0. 0. m

/gps/ang/type cos
/gps/ang/mintheta  0 deg
/gps/ang/maxtheta 90 deg

---

GRAS/trunk/r2242