#
#
##########################################################################
#
# neutronSource-cf252.txt
#
# This macro file sets G4GPS parameters to produce an isotropic 
# point source of neutrons with a Cf252 enery spectrum.
# 
##########################################################################
#
#
#
/IBD/on false
#
/gps/particle neutron
/gps/pos/type Point
/gps/pos/centre -100. 0. 0. cm
/gps/ang/type iso
# /gps/ang/maxtheta 15 deg
# /gps/ang/rot2 0 0 1

/gps/ene/type Arb
/gps/hist/type arb
#
# The Cf-252 neutron energy spectrum was taken from
# Figure 2 of A.B. Smith and  P.R. Fields, 
# Phys Rev 108 (1957) 411.
#
#                Energy (MeV)  Rel. Yield
#
/gps/hist/point  0.03791	32.71076
/gps/hist/point  0.08301	45.89684
/gps/hist/point  0.19830	59.07265
/gps/hist/point  0.34993	68.10622
/gps/hist/point  0.60544	74.34164
/gps/hist/point  0.81070	76.17980
/gps/hist/point  1.08555	73.89820
/gps/hist/point  1.55102	64.25226
/gps/hist/point  1.89664	55.40119
/gps/hist/point  2.39728	45.95365
/gps/hist/point  2.82949	37.80812
/gps/hist/point  3.50389	27.66813
/gps/hist/point  4.40363	17.72709
/gps/hist/point  5.04448	12.47039
/gps/hist/point  5.61632	8.97969
/gps/hist/point  6.24062	6.12068
/gps/hist/point  7.02125	3.73887
/gps/hist/point  8.84360	1.12916
#
# Linear interpolation between the data points is required to obtain
# the smooth energy spectrum
/gps/hist/inter Lin

/Solid/beamOn 10000