NEA-0599: NE-SPEC, Ne-213 Liquid Scintillation Detector Fast Neutron Spectra Unfolding

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NEA-0599 NE-SPEC. (Abstract last modified 07-NOV-1984)

NE-SPEC, Ne-213 Liquid Scintillation Detector Fast Neutron Spectra Unfolding

Abstract Table of Contents:

OPERATING SYSTEM

OTHER RESTRICTIONS

1. NAME OR DESIGNATION OF PROGRAM - NE-SPEC. The Unfolding Code System for the NE213 Liquid Scintillator.

2. COMPUTER FOR WHICH PROGRAM IS DESIGNED AND OTHER MACHINE VERSION PACKAGES AVAILABLE -

To request or retrieve programs click on the one of the active versions below. A password and special authorization is required.

Explanation of the status codes.

Program-name Package-ID Status NE-SPEC NEA-0599/01 Tested

Machines used: Package-ID Orig.Computer Test Computer NEA-0599/01 FACOM 230/75 IBM 3081

3. DESCRIPTION OF PROBLEM OR FUNCTION - The NE-SPEC system is composed of three types of programs:
- The code to convert the pulse height distributions from counts per channel to counts per light unit.
- The code to generate the response matrix.
- The unfolding code(s).

4. METHOD OF SOLUTION - Considering the three code types in turn:
As the unit of the pulse height distribution must be matched to that of the response matrix, it is necessary to convert from counts per channel to counts per light unit. In this system the light unit used is the Na light unit. Also a new calibration method is used to determine the coefficients of the linear expression that defines the relationship between the channel number and the light unit. This method utilizes the relations between the values of the light unit for the energy of the Compton peak and the corresponding channel number of the gamma ray sources.
The response matrix of the NE213 is obtained using Monte Carlo.
47 neutron groups are used in the test run, with cross sections from ENDF/B-IV. The light output data is that evaluated by Verbinski et al. The response matrix is reduced to 34 groups for the unfolding. The pulse height meshes are arranged at equal log spaces from 0.001 to 10.0 Na light units with 60 mesh points per decade.
For unfolding, two codes, FERDOS and ITEM-II, which are based on different principles are available, so as to check their results. FERDOS employs a constrained least squares unfolding procedure whilst ITEM-II uses an iterative unfolding method.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM - Number of data points per unit decade of pulse height intervals - max. 60.
Number of decades in the pulse height region - max. 4.
Pulse height of initial mesh in Na units - min. 0.001.
Number of channels in the measured pulse height distribution - max. 1024.
Number of data points of the pulse height distribution - max. 150.
Maximum size of response matrix is 55 (neutron energy mesh)*165 (light output mesh).

6. TYPICAL RUNNING TIME - The whole system running time required is less than 3 mins (on the FACOM 230/75).

NEA-0599/01:

NEA-DB executed the test cases on IBM 3081. The following CPU times were required for the different modules:
              SYSMATRIX       57.97 seconds
              CHNTLU           0.23
              FERDOS           0.08
              ITEM-II          2.09

7. UNUSUAL FEATURES OF THE PROGRAM -

8. RELATED AND AUXILIARY PROGRAMS - NE-SPEC is a code system that uses the data conversion code CHNTLU, the response matrix generating code SYSMTRIX, and the unfolding codes FERDOS (a modified version of FERDO) and ITEM-II.

9. STATUS
NEA-0599/01: 07-NOV-1984 Tested at NEADB

10. REFERENCES  -
- V.V. Verbinski et al.:
"Calibration of an Organic Scintillator for Neutron Spectrometry" Nucl. Instr. and Meth. 65, 8 (1968).
NEA-0599/01:
- Nobuo Sasamoto and Shun-ichi Tanaka:
  The Unfolding Code System for the NE213 Liquid Scintillator
  JAERI-M6952 (February 1977)

11. MACHINE REQUIREMENTS - Less than 85 k core storage.

NEA-0599/01:

To run the test case, main storage requirements for the different modules are:
                        SYSMATRIX      256K bytes
                        CHNTLU         136K
                        FERDOS         292K

12. PROGRAMMING LANGUAGE(S) USED -
NEA-0599/01: FORTRAN-IV

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED - MVS-SP (IBM3081)

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS -

15. NAME AND ESTABLISHMENT OF AUTHOR -
          N. Sasamoto and S. Tanaka
          Japan Atomic Energy Research Institute
          Division of Reactor Engineering
          Tokai-Mura
          Naka-gun, Ibaraki-ken
          Japan.

16. MATERIAL AVAILABLE -
NEA-0599/01:
NEA0599_01.003    NE-SPEC INFORMATION FILE                           96 records
NEA0599_01.004    SYSMATRIX SOURCE                                  383 records
NEA0599_01.005    CHNTLU SOURCE                                     151 records
NEA0599_01.006    FERDOS SOURCE                                     278 records
NEA0599_01.007    ITEM-II SOURCE                                    270 records
NEA0599_01.008    JCL                                                81 records
NEA0599_01.009    SYSMATRIX INPUT DATA                             1985 records
NEA0599_01.010    CHNTLU INPUT DATA                                  89 records
NEA0599_01.011    FERDOS INPUT DATA                                  28 records
NEA0599_01.012    ITEM-II INPUT DATA                                 28 records
NEA0599_01.013    SYSMATRIX PRINTED OUTPUT                          561 records
NEA0599_01.014    CHNTLU PRINTED OUTPUT                             432 records
NEA0599_01.015    CHNTLU PUNCHED OUTPUT                              52 records
NEA0599_01.016    FERDOS PRINTED OUTPUT                              78 records
NEA0599_01.017    ITM-II PRINTED OUTPUT                             330 records

17. CATEGORIES -

- O. Experimental Data Processing

Keywords: DATA PROCESSING, GAMMA RADIATION, LIQUID SCINTILLATORS, MONTE CARLO METHOD, MULTI-CHANNEL ANALYSERS, NEUTRON SPECTRA, RADIATION DETECTORS, SPECTRA UNFOLDING

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