NESC0465 RESEND/ADLER

1. NAME OR DESIGNATION OF PROGRAM:  RESEND/ADLER

3. DESCRIPTION OF PROBLEM OR FUNCTION

RESEND generates  infinitely-
dilute, unbroadened,  point cross sections  in the ENDF  format by
combining  ENDF  File  3 background  cross  sections  with  points
calculated from ENDF File 2 resonance parameter data.
   ADLER  calculates total,  capture, and  fission cross  sections
from the corresponding Adler-Adler parameters in the ENDF/B File 2
Version II data and also Doppler-broadens cross sections.

4. METHOD OF SOLUTION

RESEND calculations are done  in two steps by
two separate sections of the program.   The first section does the
resonance calculation  and stores the  results on a  scratch file.
The second  section combines the data  from the scratch  file with
background cross sections and prints the results.
   ADLER uses the Adler-Adler formalism.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

RESEND expects its
input to be a standard mode BCD ENDF file (Version II/III).  Since
the output is also  a standard mode BCD ENDF file,  the program is
limited by  the six  significant figure  accuracy inherent  in the
ENDF formats.   (If the cross section  has been calculated  at two
points  so  close in  energy  that  only their  least  significant
figures differ, that  interval is assumed to  have converged, even
if  other convergence  criteria  may not  be  satisfied.)  In  the
unresolved  range the  cross sections  have been  averaged over  a
Porter-Thomas  distribution.   In  some   regions  the  calculated
resonance  cross sections  may  be negative.   In  such cases  the
standard convergence criterion would  cause an unnecessarily large
number of  points to  be produced  in the  region where  the cross
section  becomes  zero.   For  this  reason  an  additional  input
convergence criterion (AVERR) may be  used.  If the absolute value
of the cross section at both ends  of an interval is determined to
be less than AVERR then the interval is assumed to have converged.
There are no limitations on the  total number of points generated.
The  present ENDF  (Version  II/III)  formats restrict  the  total
number of points that can be given for a reaction type to 5000.
   ADLER can handle resonance data up  to a maximum of 10 isotopes
with a total number of 500  resonances.  The code assumes that the
resolved resonance parameters are given for one energy range which
is the same for  all the isotopes of an element.   The mesh points
at which the  cross sections are calculated can  be varied.  Since
the calculated data  are not stored, an increase in  the number of
mesh points does not conflict with any storage requirement.

6. TYPICAL RUNNING TIME

To produce the U238 (ENDF MAT = 1103) cross
sections with a  1 percent accuracy (ERR =  0.01) RESEND generates
about 12,000  resonance points  and requires about  1 hour  on the
PDP10.  For  less complex materials  running time  is considerably
shorter.
   ADLER calculations  of cross  sections of  one isotope  with 37
resonances  and  20  mesh-points between  resonances  requires  21
seconds without Doppler-broadening  and 209 seconds  with Doppler-
broadening.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

RESEND combines  the features  of
the  resonance   region  codes   AVRAGE3,  AVRAGE4,   and  SIGMA2.
Additional subroutines under development will further enable it to
replace ADLER and RAMP1 (NESC Abstract 492).

10. REFERENCES

M. R. Bhat, ENDF/B Processing Codes for the Resonance
Region, BNL-50296 (ENDF-148), June 1971.
             M. K. Drake, Ed., Data Formats and Procedures for the
ENDF Neutron  Cross Section Library,  BNL-50274(T-601) (ENDF-102),
Vol. 1, October 1970.
             Odelli Ozer, Program RESEND, BNL-17134, January 1972.
             D.  B. Adler  and F.  T. Adler,  Analysis of  Neutron
Resonances in  Fissile Elements,  Programs CODILLI,  CURVEPLOT and
SIGMA, COO-1546-3, September 1966.

11. MACHINE REQUIREMENTS

RESEND requires  24K (decimal) core  with 2
scratch units, an input unit for the  ENDF data, an output unit, a
unit for reading in the run  parameters (teletype or system input)
and  a unit  for  printing  run-associated messages  (teletype  or
system output).  ADLER requires 37K (octal) memory.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:   SCOPE 3.0.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

                 M. R. Bhat and O. Ozer
                 National Nuclear Data Center
                 Brookhaven National Laboratory
                 Upton, Long Island, New York  11973

File name	File description	Records
ENDF-148	AVRAGE-4 SOURCE PROGRAMME	0
ENDF-148	AVRAGE-4 SAMPLE INPUT	0
ENDF-148	AVRAGE-4 SAMPLE OUTPUT	0