DROSG-2000: Neutron Source Reactions

DROSG-2000: Neutron Source Reactions

Data files with computer codes for 59 accelerator-based two-body neutron source reactions

v. 2.21, IAEA-NDS-87 Rev. 9, May 2005

prepared by M. Drosg Institute for Experimental Physics, University of Vienna

Abstract: This package contains data and three computer codes to calculate:

- neutron energies, differential cross-sections and differential yields;

- thick-target yields and white neutron spectra from two-body neutron producing reactions;

- differential cross sections and energies of (n,p), (n,d), (n,t) and (n,4He) reactions which are time-reversed neutron production reactions (using detailed balance calculations)

The package is can be downloaded from http://www-nds.iaea.org . It supersedes the package DROSG-96.

Update History:

The original package named DROSG-87 provided energy and differential cross section data of p-T, d-D, d-T, p-7Li and their inverse counterparts. The first source code was just about three pages of FORTRAN-IV. Soon it was clear that differential neutron yield data were of much interest so that neutron sources could be compared. After this feature had been included (in the code NEUYIE, "neutron yield") it was straightforward to provide thick-target neutron yield information by way of the code WHIYIE ("white yield"). When a need arose to predict the differential yields and energies of (n, charged particle) reactions in 3He counters, it was easy to introduce the necessary detailed balance calculations into NEUYIE to generate the code TIMREV which gives the energy and cross section data of the time reversed reactions covered by NEUYIE. When heavy ion acceleration became more common, inverse (p,n) and (d,n) reactions had to be considered. In general, inverse reactions have very desirable properties: wider monoenergetic range and, for endothermic reactions, kinematic neutron collimation with enhanced laboratory cross sections. Therefore, a revised package (DROSG-96) took care of this development: it included the three codes and provided data bases for 15 (p,n) reactions and 7 (d,n) reactions so that together with inverse reactions 33 neutron source reactions were covered.

The latest package, DROSG-2000, supersedes DROSG-96 and DROSG-87. It is a major revision.

1) All iteration routines were changed. They are based now on physical properties so that convergence is guaranteed under any input condition. Besides any iteration occurs within about 25 steps increasing the speed in some cases considerably.

2) All calculations are done now with double precision.

3) Some relevant physical properties (thresholds, double valued range and opening angle of kinematically collimated sources) are made available right after the selection of the desired source reaction, and energy, resp..

4) Some (exotic) monoenergetic (d,n) reactions and (alpha,n) reactions and their inverse reactions were added so that the database comprises

- 15 (p,n) reactions

- 11 (d,n) reactions and

- 5 (alpha,n) reactions.

Including the inverse reactions a total of 57 neutron producing reactions are presently provided.

VERSION 2.0: 17-NOV-2000 Code was made compatible with LAHEY-FORTRAN for LINUX and for DEC-UNIX

VERSION 2.1: 02-JAN-2002 Minor changes in data files D2HAGS.koe, D3HAGS.koe, D9BEGS.koe, P3HAGS.koe, P7LIGS.koe and P7LIES.koe; changes of the source code in 6 of the 9 *.f90 files as indicated:

ANGINP.F90 Added exit on error for angle input by file option

CHKANG.F90 changed format of threshold output

ENINPO.F90 changed wording of 2 messages

NYIOUT.F90 added output of Q-value

RECOUT.F90 changed FORMAT # 87

WHIOUT.F90 added output of exit energy of beam in *.spc

VERSION 2.2:02-JAN-2003 Database: rearranged SETYIE.TAB to accomodate two new reactions: 18O(p,n)18F and 14N(d,n)15O; and five new targets: 202 d-octane target, 203 LiD target, 702 7LiH target, 902 7LiH target, 313 LiD target. extended differential cross section energy range for p-7Li using ENDF/B-VI MOD 1 Evaluation, July 1999 by M.B. Chadwick,P.G.Young.

Source code (changes in the *.f90 files):

NEUYIE: rearranged input in subr. RDSTUP to match new SETYIE.TAB

ANGCAL,ANGINP,ENINPO,LEGINT,NEUYIE,NYIOUT,RECOUT and WHIOUT: variable HANGSA now in COMMON /masse/

ENINPO: in subr. WHISUM now output of 1st angle

ANGINP,LEGINT and NEUYIE: added BLANK='NULL' in all OPEN statements for files that are read

ANGCAL: increased number of digits of ENT in FORMAT 100 (display)

RECOUT: increased number of digits in printout

WHIOUT: in subroutine PLDTIN: changed FORMAT 100

VERSION 2.21:15-MAY-2005: changed files mass.tab and *.koe to account for the latest atomic masses (2003).

Description of the 3 codes:

1) NEUYIE: Accelerator-based mononenergetic neutron production This program calculates neutron energies, differential cross-sections and (for isotopic pure targets) differential neutron yields for monoenergetic neutron sources using internal tables. The Legendre coefficients of the differential cross sections are stored in the files *.KOE, the energy loss tables needed for the neutron yield calculations in the files *.ELS. The neutron yields are given for an energy loss of the projectile that results in 10 keV neutron energy spread at 0 degree.

2) WHIYIE: White neutron yields from two-body reactions This program calculates angular differential thick-target neutron yields of white neutron sources that are based on the two-body reactions covered under 1). As an option, a white spectrum at a chosen angle ready for plotting is produced.

3) TIMREV: Differential cross sections and energies of (n,p), (n,d), (n,t) and (n,alpha) reactions This program calculates differential cross sections and energies of some (n,p), (n,d), (n,t) and (n,alpha) reactions by detailed balance from the time reversed reactions covered under 1).