MUPHOTON

Summary

Controls muon photonuclear interactions ​​

See also PAIRBREM, PHOTONUC

WHAT(1) :

flag to switch on muon nuclear interactions:

= -1.0:

no muon photonuclear interaction

= 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

= 1.0  if no DEFAULTS card is present, or if it is present with SDUM = CALORIMEtry, NEW-DEFAults, ICARUS or PRECISIOn.

= -1.0

otherwise

WHAT(2) :

reserved for code development

WHAT(3) :

reserved for code development

WHAT(4) =
lower bound of the indices of materials, or corresponding name, in which muon nuclear interactions must be simulated
(“From material ``WHAT(4)``…”)
Default

= 3.0

WHAT(5) =
upper bound of the indices of materials, or corresponding name, 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

Notes

  1. Other high-energy interactions of muons with nuclei (pair production, bremsstrahlung) are controlled by option PAIRBREM, which applies also to charged hadrons.

  2. 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

The same example, name based:

*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+...
PAIRBREM         3.0       0.0    0.0005    COPPER    SILVER
MUPHOTON         1.0       0.0       0.0    COPPER    SILVER