AVRIGEANU.readme


                Partial Level Densities: Analytical Approach
           (M. Avrigeanu et al, Bucharest, Romania, September 1997)
           ********************************************************
AVRIGEANU.FOR is the Fortran code (original code name PLD.FOR), providing 
a set of subroutines for calculating p-h level densities using analytical
expressions for various equidistant and Fermi-gas single-particle models.
The following text is included also in the comment part of the file
AVRIGEANU.FOR.
C*******************************************************************************
C     PROGRAM PLD                                                              *
C     FORTRAN SUBROUTINES FOR CALCULATION OF PARTIAL LEVEL DENSITIES USED IN   *
C     PREEQUILIBRIUM NUCLEAR REACTION MODELS, FOR THE DEVELOPMENT OF THE       *
C     "REFERENCE INPUT PARAMETER LIBRARY" FOR NUCLEAR MODEL CALCULATIONS OF    *
C     NUCLEAR DATA (NUCLEAR DATA SECTION/IAEA-VIENNA PROJECT , 1994-1997).     *
C                                                                              *
C     CARRIED OUT UNDER RESEARCH CONTRACT NO. 8886/R0-R1/RBF BETWEEN           *
C     INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, AND                          *
C     INSTITUTE FOR NUCLEAR PHYSICS AND ENGINEERING, BUCHAREST, ROMANIA.       *
C     CHIEF INVESTIGATOR: DR. M. AVRIGEANU, INPE-BUCHAREST.                    *
C     SEPTEMBER 1997.                                                          *
C                                                                              *
C     OS/COMPILER: MS-DOS v.5/ MS-FORTRAN77 v.5.0                              *
C*******************************************************************************
C
C I.DESCRIPTION OF THE SUBROUTINES/FUNCTIONS (* - 1997 new or major changes)
C   ========================================
C
C  1. MAIN. * Reads the input data and organizes the calculation of the 
C       partial nuclear state densities (PSD) w(p,h,E) by using the specified 
C       formula [1-8], and partial level densities (PLD) D(p,h,E,J) by 
C       using the formalism of the spin cutoff factors of Fu [9,10]. It
C       calculates (i) the nuclear state density w(E) as the PSD-sum over
C       all allowed exciton numbers (p=h) for which PSD is higher than
C       WMINACC=0.1 /MeV, and (ii) the total level density D(E) as the 
C       PLD-sum over the nuclear angular momentum J and allowed particle 
C       numbers p=h. At the same time are calculated the corresponding 
C       Wasym(E)- or Dasym(E)-values given by the asymptotical/'closed' 
C       formulae of the equidistant Fermi gas model (FGM) in order to make 
C       possible tests of the overall consistency. A two-fermion system 
C       correction [11] is involved optionally when the one-component 
C       Fermi gas formulae are used for calculation of PSDs.
C
C  2. PRINTIN. Prints the PSD/PLD formula and parameters used in calculation.
C 
C  3. PRINTWN. Tabulates values of the calculated w(p,h,E) or D(p,h,E) (the
C       latter being the sum over J of the D(p,h,E,J), i.e. the total 
C       level density for a given exciton configuration), for either 
C       (i) some given particle-hole configurations or (ii) all pairs of 
C       equal numbers of excited particles and holes. In the case (ii) 
C       there are printed also the w(E) or D(E)-values (within a first 
C       table including the PSD/PLD for p=h=1 to 7) and the corresponding 
C       Wasym(E)- or Dasym(E)-values given by the closed FGM formulae  
C       (within the second table including the PSD/PLD for p=h=8 to 16).
C       In the case of the PLD calculation for a particular (p,h) 
C       configuration it is printed also a table of the D(p,h,E,J)-values
C       but only for the last excitation energy E involved in the 
C       respective calculation; the total level density for this 
C       configuration is obtained and printed both as the D(p,h,E,J)-sum 
C       and 'D(p,h,E)-form' based on formula between this quantity and
C       w(p,h,E).
C
C  4. WIL1    Calculates the partial nuclear state density w(p,h,E) of a given 
C             exciton configuration by means of the Williams formula [1] for 
C             one-component Fermi-gas.
C 
C  5. WIL2    As WIL1 but using the two-fermion system formula.
C 
C  6. WOB1    Calculates the partial nuclear state density of a given excited
C             particle-hole configuration by means of the Betak-Dobes formula 
C             [2] with the nuclear potential finite-depth correction, for one-
C             component Fermi-gas. If a value is specified for the nucleon
C             binding energy it is carried out the calculation of the bound-
C             state density according to Oblozinsky [3].
C
C  7. WOB2    As WOB1 but using the two-fermion system formula.
C
C  8. WFU1    Calculates the PSD of a given exciton configuration by means of 
C             the formula including the advanced pairing correction by Fu [4],
C             for one-component Fermi-gas.
C
C  9. WFU2  * As WFU1 but using the two-fermion system formula.
C
C 10. WK1     Calculates the PSD of a given exciton configuration by using the 
C             improved implementation of the pairing correction by Kalbach [5,6]
C             for one-component Fermi-gas.
C
C 11. WK2   * As WK1 but using the two-fermion system formula.
C
C 12. WK3     Calculates the PSD of a given exciton configuration by using the 
C             FGM energy-dependence of the single-excited particle and 
C             single-hole state densities, and/or the finite-depth correction
C             including the nuclear-surface effects introduced by Kalbach [8]
C             for one-component Fermi-gas.
C
C 13. WK4   * As WK3 but using the two-fermion system formula.
C
C 14. WM1     Calculates the PSD of a given exciton configuration by using the 
C             exact calculation of the Pauli-exclusion effect [7] and the 
C             pairing correction by Kalbach [5,6] for one-component Fermi-gas.
C
C 15. WM2   * As WM1 but using the two-fermion system formula.
C
C 16. WR1   * Calculates the PSD of a given exciton configuration by using 
C             (i) the improved implementation of the pairing correction by 
C             Kalbach [5,6], (ii) the FGM energy-dependence of the 
C             single-excited particle and single-hole state densities, and/or 
C             (iii) the finite-depth correction including the nuclear-surface 
C             effects introduced by Kalbach [8], for one-component Fermi-gas.
C
C 17. WR2   * As WR1 but using the two-fermion system formula.
C
C 18. PFU     Calculates the advanced pairing correction by Fu [4], for the
C             one-component Fermi-gas.
C
C 19. AK    * Calculates the advanced pairing correction by Kalbach [5,6],  
C             for the one-component Fermi-gas.
C
C 20. FDC0    Calculates the nuclear potential finite-depth correction factor
C             f(p,h,E,F) [8] for one-component Fermi-gas.
C
C 21. FDC   * Calculates the nuclear potential finite-depth correction factor
C             f(p+1,h,E,F) [8] in the case of bound states and the 
C             one-component Fermi-gas.
C
C 22. SUBPLD * Calculates the partial level density D(p,h,E,J) of a given 
C             'p'-excited particle and 'h'-hole configuration for the excitation
C             energy E and nuclear spin J, and the respective total level
C             density D(p,h,E) as the sum over J of these PLDs, by using the
C             partial state density w(p,h,E) and the formalism of Fu [9,10].
C
C 23. SIG2FU  Calculates the spin cutoff factor for a given excited particle-
C             hole configuration [9].
C
C 24. FCTR    Calculates the factorial of natural numbers.
C
C
C II. REFERENCES
C     ========== 
C
C  1. F.C. Williams, Nucl. Phys. A166, 231 (1971)
C  2. E. Betak and J. Dobes, Z. Phys. A279, 319 (1976)
C  3. P.Oblozinsky, Nucl. Phys. A453, 127 (1986)
C  4. C.Y. Fu, Nucl.Sci.Eng. 86, 344 (1984)
C  5. C. Kalbach, Nucl.Sci.Eng. 95, 70 (1987)
C  6. C. Kalbach, Z.Phys. A 332, 157 (1989)
C  7. Mao Ming De and Guo Hua, J. Phys. G: 19, 421 (1993)
C  8. C. Kalbach, Phys. Rev. C 32, 1157 (1985)
C  9. C.Y. Fu, Nucl.Sci.Eng. 92, 440 (1986)
C 10. C.Y. Fu, Nucl.Sci.Eng. 109, 18 (1991)
C 11. J.M.Akkermans and H.Gruppelaar, Z.Phys. A 321, 605 (1985)
C
C
C III. INPUT DATA DESCRIPTION   (Formatted read is used for all data in order to 
C      ======================   be possible the input of only few of them, while 
C                               the rest are receiving zero-values)
C 1. NE,IOPTJ,TITLE
C    **************                                             FORMAT(2I3,74A1)
C    NE ..... Number of excitation energies.
C             If NE>0 then the calculation is carried out for the energy values
C             of E = 1, 2,.., NE MeV   (maximum NEN=200), and record No. 2 
C             should be omitted
C    IOPTJ .. Spin distribution (PLD calculation) option
C            = 0 Calculate PSD-values, i.e. w(p,h,E) or w(pP,hP,pN,hN,E), and
C                the nuclear state densities w(E) (obtained as sum over 'p' with 
C                the restriction p=h) and Wasym(E) given by the closed 
C                formulae
C            = 1 Calculate the PLDs D(p,h,E,J) or D(pP,hP,pN,hN,E,J), the total
C                level density given by the sum over J [ D(p,h,E) ] as well as 
C                over 'p' with the restriction p=h [ D(E) ], and Dform(E) given 
C                by the asymptotical/closed formula (Eq. (52) of [9])
C    TITLE .. Title of the problem
C
C 2. E(I), I=1,|NE|   (only if NE<0!) (it has to be omitted if NE>0!)
C    **************                                               FORMAT(8F10.5)
C    ... The excitation energies in MeV at which the PSD/PLDs are calculated
C
C 3. IMOD,ITFC,A,Z,UP
C    ****************                                         FORMAT(2I3,7F10.5)
C    IMOD .. Select the partial state/level density formula (odd for one-fermion
C            system and even for two-fermion system formulas):
C
C           =-1, 0  Composite/recommended formula (present work)
C           = 1, 2  F.C. Williams, Nucl. Phys. A166, 231 (1971)
C           = 3, 4  P.Oblozinsky, Nucl. Phys. A453, 127 (1986), Eqs.(7,9)
C           = 5, 6  C.Y. Fu, Nucl.Sci.Eng. 86, 344 (1984)
C           = 7, 8  C. Kalbach, Nucl.Sci.Eng.95,70(1987),Z.Phys.A 332,157(1989)
C           = 9,10  C. Kalbach, Phys.Rev. C 32, 1157 (1985)
C           =11,12  Mao Ming De, J.Phys.G 19,421(1993)
C
C    ITFC .. Option for two-fermion system correction
C           = 0    No one
C           = 1    J.M.Akkermans, H.Gruppelaar, Z.Phys. A 321,605(1985), Eq. (9)  
C    A ..... Mass number of the excited nucleus (may be omitted if GIN>0.)
C    Z ..... Atomic number of the excited nucleus
C    UP .... Pairing correction based on the odd-even mass differences
C            If UP=-1. and A>0., P-values given by Eq.(9) of Dilg et al., Nucl.
C            Phys. A217,269(1973), are adopted
C
C 4. NP0,NH0,GIN,FIN,BIN,F1IN
C    ************************                                 FORMAT(2I3,7F10.5)
C    NP0 ... Number 'p' of excited particles within the exciton configuration
C    NH0 ... Number 'h' of holes within the exciton configuration
C            If NP0=NH0=0 then the calculation is carried out for all pairs 
C            p=h=1, 2,... for which the PSD/PLD-value at the respective 
C            excitation energy E is higher than WMINACC=0.1 /MeV, followed by
C            their sum to obtain the nuclear state density w(E), respectively 
C            the total level density D(E), and the values given by the 
C            asymptotic/closed formulae of the Fermi gas model
C    GIN ... Input value of single-particle state density G in 1/MeV
C            If GIN<0. the nuclear level density parameter DR(1) is read (record
C                      No. 6) and it is adopted the value G=(6/3.14**2)*DR(1)
C            If GIN=0. and A=0. it is adopted the value G=1.0
C            If GIN=0. and A>0. it is adopted the value G=A/13.
C    FIN ... Input value of the Fermi energy F in MeV
C            If FIN=0. it is adopted the value F=1.E+06
C    BIN ... Input value of nucleon binding energy B in MeV
C            If BIN=0. it is adopted the value B=1.E+06
C    F1IN... Input value of the average effective Fermi energy F1 in MeV [8].
C            If FIN=0.0 it is adopted the value F=1.E+06.
C            If FIN<0.0 the PSD calculation by means of WR1 and WR2 functions
C            is carried out for constant G.
C
C 5. NP0,NH0,NPN0,NHN0,GIN,GN,FIN,FN,BIN,BN,F1IN,F1N
C    ***********************************************          FORMAT(4I3,6F10.5)
C    NP0 ... Number 'pP' of proton excited particles 
C    NH0 ... Number 'hP' of proton holes
C    NPN0 .. Number 'pN' of neutron excited particles 
C    NHN0 .. Number 'hP' of neutron holes
C            If NP0=NH0=NPN0=NHN0=0 the calculation is carried out for all 
C            configurations (pP=hP,pN=hN) - followed by increasing total exciton
C            numbers N=pP+hP+pN+hN=2, 4,.. - for which the sum of PSD/PLDs for a 
C            given N at the respective excitation energy E is higher than 
C            WMINACC=0.1/MeV
C    GIN ... Input value of single-proton state density G in 1/MeV
C    GN .... Input value of single-neutron state density GN in 1/MeV
C            If GIN<0 the nuclear level density parameter DR(1) is read (record
C                     No. 6) and there are adopted the values:
C                            G=Z/A*(6/3.14**2)*DR(1)
C                            GN=(A-Z)/A*(6/3.14**2)*DR(1) 
C            If GIN=0 and A=0. there are adopted the values G=GN=1.0 
C            If GIN=0 and A>0. are adopted the values G=Z/13 and GN=(A-Z)/13
C    FIN ... Input value of the proton Fermi energy F in MeV
C    FN .... Input value of the neutron Fermi energy FN in MeV
C            If FIN=0. there are adopted the values F=FN=1.E+06
C    BIN ... Input value of proton binding energy B in MeV
C    BN .... Input value of neutron binding energy BN in MeV
C            If BIN=0. there are adopted the values B=BN=1.E+06
C    F1IN... Input value of the average effective proton Fermi energy F1 in MeV.
C            If F1IN=0 it is adopted the value F1=1.E+06.
C            If F1IN<0.0 the PSD calculation by means of the WR2 functions is
C            carried out for constant G.
C    F1N ... Input value of the average effective neutron Fermi energy F1N (MeV)
C            If F1N=0 it is adopted the value F1N=1.E+06.
C            If F1N<0.0 the PSD calculation by means of the WR2 functions is
C            carried out for constant GN.
C
C 6. DR(K), K=1,3 (if GIN is negative, otherwise it has to be omitted!)
C    ************						  FORMAT(8F10.5)
C    ...    Parameters of the Back-Shifted Fermi Gas model for 
C           nuclear level density (W. Dilg et al., Nucl. Phys. A217,269(1973)]:
C    DR(1) .. Nuclear level density parameter 'a'
C    DR(2) .. Ratio of effective nuclear moment of inertia to rigid-body value
C             calculated by using the reduced nuclear radius r=1.25 fm
C    DR(3) .. Shift of the fictive nuclear ground state
C
C 7. ICONT,IEND
C    **********                                               FORMAT(2I3,7F10.5)
C    ICONT .. Output and recycle option
C            =-1 Print of the first 2 tables only (see PRINTWN description)  
C                of calculated PSD/PLD, and resumption according to IEND
C            = 0 Print of calculated PSD/PLD, and resumption according to IEND
C            = 1 New calculation starting with input-data record 1, with the
C                results printed together with those of the actual case
C            = 2 New calculation starting with input-data record 3 (conserved 
C                energy grid) 
C            = 3 Calculation for another exciton configuration given by the 
C                input-data records either 4 or 5
C            = 4 Calculation for another set of the BSFG model parameters given 
C                by the input-data record 6   
C    IEND ... Recycle option
C            = 0 End
C            = 1 New complete case starting with input-data record 1
C            = 2 New calculation starting with input-data record 3 
C            = 3 New calculation for exciton configuration on records 4 or 5
C            = 4 New calculation for BSFG model parameters given on record 6
C*******************************************************************************