J. T. Routti

MicroSAMPO PERSONAL COMPUTER BASED ADVANCED GAMMA SPECTRUM ANALYSIS SYSTEM

The widely used SAMPO Ge(Li) and HPGe gamma spectrum analysis program has been adapted to IBM Personal Computers in a thoroughly revised version MicroSAMPO. The program is intended for peak search, peak fitting, nuclide identification and activity calculations. The use of calibrated peak shape functions for peak area determination makes it possible to resolve complex multiplets with strongly overlapping peaks. Menu-driven user interface, colour graphics diplays, semi-automatic calibrations and interactive options have been designed to make the program more user-friendly. It is well suited for both spectroscopic research and routine analysis.

SAMPO80: An accurate gamma spectrum analysis method for minicomputers

Abstract In this paper we report a minicomputer version of the well known gamma spectrum analysis program SAMPO. The algorithms an the general structure of this new version called SAMPO80 are explained. We also report results of statistical tests showing that the peak locations and areas given by the new version are both consistent and accurate.

SAMPO 90 HIGH RESOLUTION INTERACTIVE GAMMA-SPECTRUM ANALYSIS INCLUDING AUTOMATION WITH MACROS

SAMPO 90 is a high performance gamma-spectrum analysis program for personal computers. It uses color graphics to display calibrations, spectra, fitting results as multiplet components, and analysis results. All the analysis phases can be done either under full interactive user control or macros and programmable function keys can be used for completely automated measurement and analysis sequences including the control of MCAs and sample changers. Accurate peak area determination of even the most complex multiplets, of up to 32 components, is accomplished using linear, non-linear and mixed mode fitting. Nuclide identification is done using associated lines techniques allowing interference correction for fully overlapping peaks. Peaked Background Subtraction can be performed and Minimum Detectable Activities calculated. The analysis reports and program parameters are fully customizable.

EXPERT SYSTEM FOR NUCLIDE IDENTIFICATION IN GAMMA SPECTRUM ANALYSIS

Gamma spectrum analysis is a standard tool in many fields today. Often the task is to find out the exact composition and concentrations of radionuclides in a measured spectrum. A full manual identification of a complex spectrum requires considerable expertise on the part of the laboratory personnel and takes usually several hours.An expert system coupled with the gamma spectrum analysis system SAMPO has been developed for automating the qualitative identification of radionuclides as well as for determinating the quantitative parameters of the spectrum components. The program is written in C-language and runs in various environments ranging from PCs to UNIX workstations. The expert system utilizes a complete gamma library with over 2600 nuclides and 80 000 lines, and a rule base of about fifty criteria including energies, relative peak intensities, genesis modes, half-lives, parent-daughter relationships etc. The rule base is furthermore extensible by the user.The performance of the expert system has been evaluated using test cases from environmental samples, sets of standard sources and activation analysis measurements, which have been carefully analyzed manually. Also. synthesized spectra have been used, where the exact composition of the sample is known in advance. Results from these tests show that the expert system performs very well, even for difficult spectra.

UNISAMPO, comprehensive software for gamma-spectrum processing

UNISAMPO is a new member of the SAMPO family of gamma-spectrum analysis programs running on Linux. Its portable graphical user interface relies on Tcl/Tk running an X-client, which obtains services from an X Window System server, allowing natural access to UNISAMPO over the Internet. UNISAMPO features a scripting ability for analyses of thousands of spectra. Peak search is based on stringent statistical criteria and peak fitting has optional step function under each peak of a multiplet. UNISAMPO will analyze 32K spectra with up to 2500 peaks, and 32 peaks in a single multiplet extending over a fitting interval of 1024 channels. It has an interface to the expert system SHAMAN for extensive peak interpretation and radionuclide identification.

Expert system for nuclide identification and interpretation of gamma-spectrum analysis

Radionuclide identification from a measured gamma-spectrum is an iterative process, where the analyst aims to find correct nuclides by decreasing the amount of possibilities by trial and error. Although the process of identification is quite complex, it can be formulated using “rules of thumb” combined with exact mathematical analysis. Thus, an expert system can be built, where the knowledge of a human expert is converted to explicit rules. In this paper expert system SHAMAN is presented, which carriess out the qualitative nuclide identification and activity determination with minimum of user intervention. The reasoning process is performed by an inference engine written in C-language. The system uses a database containing over 2000 radionuclides with about 48 000 gamma-transitions. Spectra are provided in preprocessed format, where peak energies, intensities and backgoounds with respective error estimates have been calculated by a separate analysis program.

Gamma spectrum analysis including NAA with SAMPO for windows

SAMPO for Windows is a high performance gamma spectrum analysis program. All the measurement, analysis and NAA phases can be done either under full interactive user control or user defined tasks can be used for automated measurement and analysis sequences including control of MCAs and sample changers. High resolution gamma-ray spectroscopy together with the possibility to resolve complex multiplets with high accuracy makesSAMPO very suitable for INAA. On the other hand, the possibility to automate analysis sequences allows its use effectively also in all routine NAA measurements.NAA inSAMPO is accomplished using comparative methods. Spectra of standards, flux monitors, controls and actual samples are analyzed normally to obtain the peak areas which are optionally corrected for decay. In the comparison the flux monitor results are used to correct for variations in the effective neutron flux. An optional irradiation position correction can also be applied. The controls are used to alarm for possible deviations in the results.The sophisticated spectrum analysis methods used together with the comparative NAA and monitors give accurate results limited by the systematic effects only. The Windows environment provides ease of use and further processing power is available through the interface to expert system identification of nuclides.

Adapting gamma-spectrum analysis program SAMPO for microcomputers

Abstract SAMPO is a versatile and widely used gamma-spectrum analysis program. It uses peak shape calibrations which make it possible to resolve complex multiplets. A minicomputer version SAMPO80 has been developed earlier from the original large computer version, and at the same time improved nuclide identification techniques have been included. We here report on the adaptation of SAMPO80 for low-cost 16-bit personal computers.

WWW-based remote analysis framework for UNISAMPO and SHAMAN analysis software

Summary{\rtf1\ansi\ansicpg1250\deff0\deflang1038\deflangfe1038\deftab708{\fonttbl{\f0\froman\fprq2\fcharset238{\*\fname Times New Roman;}Times New Roman CE;}} \viewkind4\uc1\pard\scaps\f0\fs24 UniSampo\scaps0 and \scaps Shaman\scaps0 are well-established analytical tools for gamma-ray spectrum analysis and the subsequent radionuclide identification. These tools are normally run locally on a Unix or Linux workstation in interactive mode. However, it is also possible to run them in batch/non-interactive mode by starting them with the correct parameters. This is how they are used in the standard analysis pipeline operation. This functionality also makes it possible to use them for remote operation over the network. We have developed a framework for running \scaps UniSampo\scaps0 and \scaps Shaman\scaps0 analysis using the standard WWW-protocol. A WWW-server receives requests from the client WWW-browser and runs the analysis software via a set of CGI-scripts. Authentication, input data transfer, and output and display of the final analysis results is all carried out using standard WWW-mechanisms. This WWW-framework can be utilized, for example, by organizations that have radioactivity surveillance stations in a wide area. A computer with a standard internet/intranet connection suffices for on-site analyses. \par }

Multicomponent activation detectors for reactor neutron spectroscopy

The authors present the principles of multicomponent activation detectors and describe a feasible way for their production and a testing procedure. They have considered detectors for a thermal reactor but multicomponent detectors can be easily designed for various applications. The same MAD, however, can be used for a fairly wide range of flux values and energy distributions around the design values. The fields of research where the authors think MADs will be useful are: research reactor spectrum measurements, e.g., for activation analysis purposes; neutron flux monitoring for radiation damage studies; fast breeder reactor experiments; fusion reactor neutronics studies; accelerator radiation physics measurements; biomedical radiation measurements. The authors are convinced that it is possible to cheaply produce highly standardized multicomponent detectors. They will, together with the use of the sophisticated SAMPO80 gamma spectrum analysis program and with suitable neutron spectrum fitting, unfolding, or adjusting programs, make neutron spectrum measurements simpler, faster, and more reliable than with the conventional separate foils technique.