ReactorConstants.hh Source File

00001 
00006 #ifndef REACTORCONSTANTS_HH
00007 #define REACTORCONSTANTS_HH
00008 
00013 class ReactorConstants{
00014   //
00015   // Common set of constants for simulation.
00016   //
00017 public:  
00018   //  
00019   // For neutrino event generation
00020   // XCorder can be changed to 0 to use neglect 1/M effects in the nubar 
00021   // cross section.
00022   // Emin,Emax set the range of thrown energy.
00023   // Rmaxgen sets the largest production radius
00024   //
00025   static const int XCorder = 1;  
00026   static const double Emin=1.85;
00027   static const double Emax=8.15;
00028   static const double Rmaxgen = 265;
00029 
00030   //
00031   // Cf source isotope
00032   //
00033   static const int Isotope = 252;
00034   //
00035   // Number of all particles we can handle
00036   //
00037   static const int Ndim = 200;
00038   //
00039   // R0 = Gd loaded radius
00040   // R1 = unloaded scintillator radius
00041   // R2 = inactive mineral oil radius
00042   //
00043   static const double R0 = 175;
00044   static const double R1 = 200;
00045   static const double R2 = 275;
00046   //
00047   // throw neutron via Gaussian or track
00048   //
00049   static const bool FastNeutronOption=0;
00050   static const double SlowNeutronStep=0.1;
00051   //
00052   // units=Kelvin
00053   //
00054   static const double Temperature=300;
00055   //
00056   // units = MeV/Kelvin
00057   //
00058   static const double Kboltzman = 8.617342e-11;
00059   //
00060   // basics
00061   //
00062   static const double pi = 3.1415928;
00063   static const double Mproton = 938.27200;
00064   //
00065   // Mneutron-Mproton
00066   //
00067   static const double Delta = 1.2933318;
00068   static const double Melectron = 0.510998902;
00069   static const double Mmuon = 105.6583692;
00070   //
00071   // 1/alpha
00072   //
00073   static const double alphainv = 137.03599976;
00074   //
00075   // Gfermi in MeV**(-2)
00076   // 
00077   static const double Gfermi = 1.16639e-11;
00078   static const double Navogadro = 6.02214199e23;
00079   //
00080   //classical electron radius
00081   //
00082   static const double Relectron = 2.817940285e-13;  
00083   //
00084   // conversion for cross sections from (Mev)**-2 to cm**2.
00085   //
00086   static const double XcMeVtoCmsqrd = 0.389379292e-21;
00087   //
00088   //  c in cm/ns
00089   //
00090   static const double c = 29.9792458;
00091   //
00092   // Scintillator and mineral oil constants taken from Chooz.
00093   // Only H are C are taken into account.
00094   //
00095   static const double density = 0.85;
00096   static const double A0=1;
00097   static const double A1=12;
00098   static const double A2=155;
00099   static const double A3=157;
00100   static const double Z0=1;
00101   static const double Z1=6;
00102   static const double Z2=64;
00103   static const double Z3=64;
00104   //
00105   // H and C mass fractions for scintillator
00106   //
00107   static const double f0=0.122;
00108   static const double f1=0.844;
00109   //
00110   // note these are the abundances of Gd155,Gd157
00111   //
00112   static const double f2=0.148;
00113   static const double f3=0.156;
00114   //
00115   // H and C mass fractions for mineral oil
00116   //
00117   static const double f4=0.133;
00118   static const double f5=0.855;
00119   //
00120   // Ionization potentials for dE/dx
00121   //
00122   static const double I0=19.2e-6;
00123   static const double I1=78.0e-6;  
00124   //
00125   // from the Chooz EPJC article
00126   // index of refraction
00127   //
00128   static const double refracGd = 1.472;
00129   static const double refracSc = 1.476;
00130   //
00131   // Gd fraction(%)
00132   //
00133   // NOTE: GdConcentration should not be blindly changed because the
00134   // values for mfpGd, tGd, GdCaptureFraction below are based on a 
00135   // GdConcentration of 0.1
00136   // Instead use ReactorDetector::SetParam_GdConcentration which 
00137   // handles resetting all these values.
00138   //
00139   static const double GdConcentration = 0.1;
00140   static const double GdConcentrationRef = 0.1;
00141   //
00142   // neutron mean free path in Gd- or un-loaded
00143   //
00144   static const double mfpGd =  6;
00145   static const double mfpSc = 40;
00146   //
00147   // mean forward displacement of neutrons (from Chooz)
00148   //
00149   static const double MeanNeuDispl = 1.7;
00150   //  capture times in ns for neutrons
00151   //  These have been adjusted to give mean capture times of 30.5 us and
00152   //  180 us in Gd and unloaded Sc, respectively 
00153   //
00154   //
00155   static const double tGd = 24.7e3;
00156   static const double tSc = 145.8e3;
00157   //
00158   // properties of capture in Gd region
00159   // GdCaptureFraction is the fraction of neutrons captured on Gd
00160   // The program assumes capture on Gd155 or 157.  Gd155frac is the
00161   // fraction pf Gd155 capture, etc.
00162   // Gd155peak is the total energy release from Gd155 capture.
00163   //
00164   static const double GdCaptureFraction = 0.841;
00165   static const double Gd155frac = 0.1848;
00166   static const double Gd155peak = 8.536;
00167   static const double Gd157frac = 0.8152;
00168   static const double Gd157peak = 7.937;
00169   //
00170   // This is an ad-hoc guess for the average number of gammas/per Gd.
00171   // The program in practice generates at least two gammas per capture
00172   // and an additional Poisson fluctuated GammasPerGd-2.
00173   //
00174   static const double GammasPerGd = 3;
00175   //
00176   // From capture on H
00177   // This is the gamma energy from np->D gamma.
00178   //
00179   static const double Hpeak = 2.2246;
00180   //
00181   // For capture on C12
00182   //
00183   static const double Cpeak = 4.9461;
00184   //
00185   // Attenuation lengths in Gd- or un-loaded
00186   // These are taken from Chooz.
00187   //
00188   static const double attenlGd =  400;
00189   static const double attenlSc = 1000;
00190   //
00191   // From Chooz-1 scintillator
00192   //  
00193   static const double PhotonsPerMeV = 5300;
00194   //
00195   // Energy Scale determined from MC
00196   //
00197   static const double EScale = 0.91675;
00198   //
00199   // Scintillator decay time (ns)
00200   //
00201   static const double ScintDecayTime = 7;
00202   //
00203   // Positron annihilation times from KAMLAND 
00204   //    Y. Kino et al.
00205   //    J. Nucl. Radiochem. Science 1, 63, 200
00206   // Not yet used.
00207   //
00208   static const double ShortPosFrac0 = 0.30;
00209   static const double ShortPosFrac1 = 0.21;
00210   static const double LongPosFrac = 0.49;
00211   static const double ShortPosTime0 = 0.19;
00212   static const double ShortPosTime1 = 0.48;
00213   static const double LongPosTime = 3.41;
00214   //
00215   // Some PMT properties.
00216   // 8 inch diameter PMT
00217   //
00218   static const double PMTcoverage = 0.2;
00219   static const double PMTdiameter = 20.16;
00220   //
00221   // Quantum efficiency for photostatistics. 
00222   //
00223   static const double PMTqe = 0.2;
00224 };
00225 #endif