THE EGS5 CODE SYSTEM

vi=0.0
wi=1.0
iri=2
wti=1.0
ncases=10
idinc=-1
!Region number 2 is the incident region
!Weight factor in importance sampling
!Number of histories to run
ei=1000.d0 !Total energy (MeV)
ekin=ei+iqi*RM !Incident kinetic energy
Note that the variables initialized above are the ones passed to EGS5 subroutine SHOWER, as described
below in step 8.
B.4.5 HATCH Call (Step 5)
When the user code MAIN calls the EGS HATCH subroutine, EGS is “hatched” by executing some
necessary once-only initializations and reading material data for the media from a data set that
created by PEGS. The required call is, trivially:
! ==========
call hatch
! ==========
Some examples of reports from HATCH are shown below. The following is a typical output
message when DUNIT has not been changed (and Rayleigh data is included in the file):
RAYLEIGH DATA AVAILABLE FOR MEDIUM
1 BUT OPTION NOT REQUESTED.
EGS SUCCESSFULLY ’HATCHED’ FOR ONE MEDIUM.
For a non-default specification of DUNIT (DUNIT=2.54, for example), the output report from
HATCH would look like the following (for two media and no Rayleigh data):
DUNIT REQUESTED&USED ARE: 2.54000E+00 2.54000E+00(CM.)
EGS SUCCESSFULLY ’HATCHED’ FOR 2 MEDIA.
Failure to successfully “hatch” a medium because it could not be found in the PEGS data file
results in message below, and execution is terminated by HATCH .
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