controls muon photonuclear interactions
(see also PAIRBREM, PHOTONUC)
WHAT(1) : flag to switch on muon nuclear interactions:
= -1.0 : resets to default (muon nuclear interactions are not
simulated)
= 0.0 : ignored
= 1.0 : full simulation of muon nuclear interactions and
production of secondary hadrons
= 2.0 : muon nuclear interactions are simulated but no
secondary hadron is produced; the energy lost by the
muon is deposited at the point of interaction
Default = 0.0 (ignored)
WHAT(2) = ratio of longitudinal to transverse virtual photon
cross-section
Warning: for code development only, do not change!
If changed the new value is applied to ALL materials.
Default = 0.25.
WHAT(3) = fraction of rho-like interactions ( must be < 1).
Warning: for code development only, do not change!
If changed the new value is applied to ALL materials.
Default = 0.75.
WHAT(4) = lower bound of the indices of the material in which muon
nuclear interactions must be simulated
("From material WHAT(4)...").
Default = 3.0.
WHAT(5) = upper bound of the indices of the material in which muon
nuclear interactions must be simulated
("...to material WHAT(5)...")
Default = WHAT(4)WHAT(6) = step length in assigning indices. ("...in steps of
WHAT(6)").
Default = 1.0
SDUM : not used
Default (option MUPHOTON not given): muon nuclear interactions
are not simulated
Notes: Other high-energy interactions of muons with nuclei (pair
production, bremsstrahlung) are controlled by option
PAIRBREM, which applies also to charged hadrons.
Use of WHAT(1) = 2.0 (interaction without transport of the
secondaries) gives the correct muon straggling but
simulates only in an approximate way the energy deposition
distribution. A similar approach is found in A. Van
Ginneken's codes CASIM and MUSIM [Van75,Van86].
Example :
* Explicit pair production and bremsstrahlung requested for heavy charged
* particles in materials 12 and 13, provided the energy of the secondary
* electrons and positrons is > 500 keV. No threshold is requested for photon
* production. For muons, explicit nuclear interactions are also requested.
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
PAIRBREM 3.0 0.0 0.0005 12.0 13.0
MUPHOTON 1.0 0.0 0.0 12.0 13.0
