Some function moved to AliZDC
[u/mrichter/AliRoot.git] / GEANT321 / gstrag / gstxin.F
1 *
2 * $Id$
3 *
4 * $Log$
5 * Revision 1.1.1.1  1995/10/24 10:21:39  cernlib
6 * Geant
7 *
8 *
9 #include "geant321/pilot.h"
10 *CMZ :  3.21/02 29/03/94  15.41.25  by  S.Giani
11 *-- Author :
12       SUBROUTINE GSTXIN
13 *   ********************************************************************
14 *   *                                                                  *
15 *   *   Initialization of the values needed in computation of          *
16 *   *   dN^2/dE/dx as in                                               *
17 *   *   Grishin,Ermilova,Kotelnikov,NIM A307(1991),273                 *
18 *   *                 PLN 18.04.92, data tables of ILG                 *
19 *   *                                                                  *
20 *   *   ==> Called by : GSTINI                                         *
21 *.  *       Authors   : P. Nevski, K. Lassila-Perini                   *
22 *   *                                                                  *
23 *   ********************************************************************
24 #include "geant321/gconsp.inc"
25 #include "geant321/gcmate.inc"
26 #include "geant321/gccuts.inc"
27 #include "geant321/gcstra.inc"
28 *
29       REAL NAV,MB,ME,NE
30 *
31 *   1 ev to erg [erg]
32       PARAMETER (ERG=1.60218E-12)
33 *   1mb to cm2
34       PARAMETER (MB=1E-18)
35 *   Electron mass [g]
36       PARAMETER (ME=9.10943E-28)
37 *   Electron charge[ESU]
38       PARAMETER (QE=4.80321E-10)
39 *   Plank constant[erg]
40       PARAMETER (H=1.05457E-27)
41 *
42 *     ------------------------------------------------------------------
43 *
44 *   -----    physic constants
45       EPPS=0.01
46       EMIN=EM(1)-EPPS
47       EMAX=LOG(DCUTE*1.E9)
48 *
49       NAV = AVO*1.E24
50 *
51 *   Electron mass in ev
52       MEEV=ME*CLIGHT**2/ERG
53 *
54 *   electron radius[cm]
55       R0=QE**2/(ME*CLIGHT**2)
56 *
57 *   Plank constant in ev
58       HE=H*CLIGHT/ERG
59 *
60 *   Gas density
61       RO=DENS
62 *
63 *   Electron density
64       NE=NAV*Z/A*RO
65 *
66 *   plasma freq**2 [ev]
67       WP2=4*PI*R0*NE*HE**2
68 *
69 *   x-section to F.osc
70       S1=MB/(2*PI**2*R0*HE*Z)
71 *
72 *   dN/dx scale
73       S2=2*PI*R0*NE*QE**2/ERG
74 *
75       NTAB = NP
76       SFINT=0
77 *
78 *    Integration of the oscillator strength function
79 *    (photoelectric cross-section)
80       DO 10  IE=NTAB,1,-1
81          E1 = EMM(IE)
82          IF (IE.EQ.NTAB) THEN
83             E2 = EMAX
84          ELSE
85             E2 = EMM(IE+1)
86          ENDIF
87          SFINT = SFINT+ GOSCIN(EXP(E1),EXP(E2))
88          FINT(IE)=SFINT
89    10 CONTINUE
90 *
91 *   Normalization of the integrated cross-section
92       DO 20  IE=1,NTAB
93          FINT(IE)=LOG(FINT(IE)/SFINT)
94    20 CONTINUE
95 *
96 *   Calculation of the real and imaginary parts of the
97 *   complex dielectric constant
98       DO 30  IE=1,NTAB
99          E=EXP(EMM(IE))
100          EPSI(IE)=LOG(WP2*PIBY2*GPHSG2(E*1E-9)/(SFINT*E))
101 *      scaled by
102          EPSR(IE)=WP2*GKOKRI(E,EXP(EMIN),DCUTE*1E9)*E/SFINT
103    30 CONTINUE
104       END