PSR-0101 HYPERMET/A1.
HYPERMET, Ge(Li) Detector Multichannel Analyser Gamma Spectra Evaluation
NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES
[ top ]
[ top ]
To submit a request, click below on the link of the version you wish to order.
Only liaison officers are authorised to submit online requests. Rules for requesters are
available here.
| Program name | Package id | Status | Status date |
|---|---|---|---|
| HYPERMET-2.7 | PSR-0101/02 | Tested | 04-JUN-1985 |
| HYPERMET | PSR-0101/03 | Arrived | 04-DEC-2001 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| PSR-0101/02 | CDC 3800 | CDC CYBER 74 |
| PSR-0101/03 | FACOM M-190 |
[ top ]
3. DESCRIPTION OF PROBLEM OR FUNCTION
HYPERMET is used to perform an automatic analysis of a multichannel gamma-ray pulse-height spectrum taken with a germanium detector. The spectrum is searched for peaks within a specified region. When found, a subregion is defined about each peak or group of peaks and a non-linear least-squares fit is performed to a parameterized peak shape plus background using an iterative variable-metric technique to search for the best values of the parameters.
When all regions have been searched a final table is printed of the position, width, area, and count rate (and the standard deviation of each) for all peaks found in all regions of the spectrum. Any regions where chisquare exceeds an upper limit, standard deviations will be flagged in the final table by a minus sign in front of the region number.
A number of options are available including an energy calibration, correction for radioactive decay, and a CALCOMP plot of each fit.
HYPERMET is used to perform an automatic analysis of a multichannel gamma-ray pulse-height spectrum taken with a germanium detector. The spectrum is searched for peaks within a specified region. When found, a subregion is defined about each peak or group of peaks and a non-linear least-squares fit is performed to a parameterized peak shape plus background using an iterative variable-metric technique to search for the best values of the parameters.
When all regions have been searched a final table is printed of the position, width, area, and count rate (and the standard deviation of each) for all peaks found in all regions of the spectrum. Any regions where chisquare exceeds an upper limit, standard deviations will be flagged in the final table by a minus sign in front of the region number.
A number of options are available including an energy calibration, correction for radioactive decay, and a CALCOMP plot of each fit.
[ top ]
4. METHOD OF SOLUTION
First a peak search is made to determine the locations of any peaks within the specified region. The search is completely automatic with a high probability of finding all true peaks while discriminating against statistical fluctuations, Compton edges, and other spurious or non-peak features of the spectrum. When a peak is found, a search is made for any additional close-lying peaks which could distort the fit if not included. A fitting sub-region is then defined about the peak or peaks. Within this sub- region initial estimates are made for the parameters such as back- ground level, slope and curvature, peak height above background, peak tailing parameters, etc. to use as starting values for the fit. A semi-empirical parameterized peak shape function has been developed to be both complete enough and flexible enough to give a satisfactory fit to the variety of peak shapes, sometimes overlapping.
An iterative non-linear least squares fit is then performed for optimum values of the peak shape and background parameters using an improved variable-metric fitting routine by Fletcher (4). If a good fit is obtained, the final parameters and resultant fit are printed out. If not a good fit, attempts are made to improve the fit; the residuals are searched for the largest statistically weighted value of data minus fit, and a new fit is made with an additional peak at the position of the largest residual. In this way even very weak but statistically significant peaks on the shoulder of a strong peak are detected and analyzed.
First a peak search is made to determine the locations of any peaks within the specified region. The search is completely automatic with a high probability of finding all true peaks while discriminating against statistical fluctuations, Compton edges, and other spurious or non-peak features of the spectrum. When a peak is found, a search is made for any additional close-lying peaks which could distort the fit if not included. A fitting sub-region is then defined about the peak or peaks. Within this sub- region initial estimates are made for the parameters such as back- ground level, slope and curvature, peak height above background, peak tailing parameters, etc. to use as starting values for the fit. A semi-empirical parameterized peak shape function has been developed to be both complete enough and flexible enough to give a satisfactory fit to the variety of peak shapes, sometimes overlapping.
An iterative non-linear least squares fit is then performed for optimum values of the peak shape and background parameters using an improved variable-metric fitting routine by Fletcher (4). If a good fit is obtained, the final parameters and resultant fit are printed out. If not a good fit, attempts are made to improve the fit; the residuals are searched for the largest statistically weighted value of data minus fit, and a new fit is made with an additional peak at the position of the largest residual. In this way even very weak but statistically significant peaks on the shoulder of a strong peak are detected and analyzed.
[ top ]
[ top ]
PSR-0101/02
NEA-DB executed the test case included in the package on CDC CYBER 740 in 130 seconds of CPU time.[ top ]
[ top ]
[ top ]
| Package ID | Status date | Status |
|---|---|---|
| PSR-0101/02 | 04-JUN-1985 | Tested at NEADB |
| PSR-0101/03 | 04-DEC-2001 | Masterfiled Arrived |
[ top ]
PSR-0101/02, included references:
- G.W. Phillips:Guide to HYPERMET Version 2.7 . (August 1976)
- G.W. Phillips and K.W. Marlow:
Program HYPERMET for Automatic Analysis of Gamma-Ray Spectra from
Germanium Detectors. NRL Memorandum Report 3198 (January 1976)
PSR-0101/03, included references:
- G.W. Phillips and K.W. Marlow:Program HYPERMET for Automatic Analysis of Gamma-Ray Spectra from
Germanium Detectors. NRL Memorandum Report 3198 (January 1976)
- G.W. Phillips:
Guide to Program HYPERMET Version A.1. (February 1977)
[ top ]
11. MACHINE REQUIREMENTS
Except for a few system input-output routines program HYPERMET will fit into one 32k word bank on a CDC 3800.
Except for a few system input-output routines program HYPERMET will fit into one 32k word bank on a CDC 3800.
PSR-0101/02
131,300 (octal) words of main storage on CDC CYBER 740.[ top ]
| Package ID | Computer language |
|---|---|
| PSR-0101/02 | FORTRAN-IV |
| PSR-0101/03 | FORTRAN-IV |
[ top ]
PSR-0101/02
NOS 1.4-531 (CDC CYBER 740).[ top ]
[ top ]
[ top ]
PSR-0101/03
source program mag tapeHYPERMET Source SRCTPreport NRL Memorandum Report 3198 (January 1976) REPPT
report Guide to HYPERMET (February 1977) REPPT
PSR-0101/02
| File name | File description | Records |
|---|---|---|
| PSR0101_02.003 | INFORMATION FILE | 72 |
| PSR0101_02.004 | JCL TO EXECUTE TEST CASE | 20 |
| PSR0101_02.005 | HYPERMET SOURCE PROGRAM | 4026 |
| PSR0101_02.006 | FLETCHER SOURCE PROGRAM | 45 |
| PSR0101_02.007 | HYPERMET TEST CASE INPUT DATA | 7 |
| PSR0101_02.008 | CALIBRATION RUN 301 | 513 |
| PSR0101_02.009 | HYPERMET TEST CASE PRINTED OUTPUT | 2655 |
| PSR0101_02.010 | CALIBRATION RUN IN CANBERRA FORMAT | 1 |
Keywords: Li-drifted ge detectors, gamma detectors, gamma spectra, least square fit, multi-channel analysers, spectra unfolding.