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G4InuclParamAngDst.cc
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25 //
26 // Author: Michael Kelsey (SLAC)
27 // Date: 22 April 2013
28 //
29 // Description: intermediate base class for INUCL parametrizations of
30 // three-body angular distributions in Bertini-style cascade
31 //
32 // 20130308 M. Kelsey -- Move PQ,PR calculation to G4InuclSpecialFunctions.
33 // 20150608 M. Kelsey -- Label all while loops as terminating.
34 
35 #include "G4InuclParamAngDst.hh"
37 #include "G4InuclParticleNames.hh"
38 using namespace G4InuclSpecialFunctions;
39 using namespace G4InuclParticleNames;
40 
41 
42 // Use coefficients in power expansion of random fraction
43 
45  if (verboseLevel>3) {
46  G4cout << theName << "::GetCosTheta: ptype " << ptype << " ekin " << ekin
47  << G4endl;
48  }
49 
50  G4int J = (ptype==pro || ptype==neu) ? 0 : 1; // nucleon vs. other
51  if (verboseLevel > 3) G4cout << " J " << J << G4endl;
52 
53  const G4int itry_max = 100; // Parametrizations aren't properly bounded
54 
55  G4double Spow = -999.;
56  G4int itry = 0;
57 
58  /* Loop checking 08.06.2015 MHK */
59  while ((Spow < 0. || Spow > 1.) && itry < itry_max) {
60  itry++;
61  Spow = randomInuclPowers(ekin, coeffAB[J]);
62  }
63 
64  if (itry == itry_max) { // No success, just throw flat distribution
65  if (verboseLevel > 2) {
66  G4cout << theName << "::GetCosTheta -> itry = itry_max " << itry
67  << G4endl;
68  }
69 
70  Spow = inuclRndm();
71  }
72 
73  return 2.0*Spow - 1.0; // Convert generated [0..1] to [-1..1]
74 }