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Title: Isotope Identification


The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.

  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
OSTI Identifier:
Report Number(s):
TRN: US1800047
DOE Contract Number:
Resource Type:
Technical Report
Country of Publication:
United States

Citation Formats

Karpius, Peter Joseph. Isotope Identification. United States: N. p., 2017. Web. doi:10.2172/1392888.
Karpius, Peter Joseph. Isotope Identification. United States. doi:10.2172/1392888.
Karpius, Peter Joseph. 2017. "Isotope Identification". United States. doi:10.2172/1392888.
title = {Isotope Identification},
author = {Karpius, Peter Joseph},
abstractNote = {The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.},
doi = {10.2172/1392888},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2017,
month = 9

Technical Report:

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  • A new isotope cluster identification program, named Reverse Cluster Search (RCS) is presented in full to assist the mass spectrometrist in the identification of unknowns. Given a clean, complete isotope cluster from a mass spectrum, its empirical formula can be found through the calculations of RCS. RCS was tested on known spectra which fit certain parameters of composition and spectral quality. Correlation between the matches given by RCS and the actual formula was excellent. RCS was written to run on both a DEC VAXStation 3500 and IBM PC compatibles. A companion program is also included which is called Forward Clustermore » Search (FCS). FCS will calculate theoretical mass spectral isotope clusters from empirical formula data. The purpose of this report is to provide the complete code for a Pascal program which is called Reverse Cluster Search (RCS). The authors goal was to develop a computer program to rapidly identify chemical formulas from mass spectral isotope cluster data requiring minimal disk storage and memory. Relying entirely upon low resolution mass spectral cluster data to predict or confirm empirical formulas is not recommended. High resolution, exact mass data is always preferred when complete confidence is required in the formula assignment; however, the presence of certain isotropic elements must be supported by the cluster data.« less
  • The Department of Physics at San Diego State University has maintained a Neutron Generator facility in room P-32C since the mid 1960`s. This facility has provided students and faculty with a resource for the study of neutron interactions with matter, such as activation analysis, flux determinations, cross section determinations and shielding studies. The model 9500 was built by Texas Nuclear Research in the early 1960`s, and could be used for either photon or neutron generation, depending on the source ions introduced into the accelerator`s plasma bottle and the target material. In February of 1988, the Texas Nuclear Research neutron generatormore » was replaced by a unit manufactured by Kaman Sciences Corporation. The Texas Nuclear unit was then removed and stored for later disassembly and disposal. In the summer of 1993, the neutron generator was disassembled into three large sections consisting of the titanium-tritide target, the oil diffusion pump and the corona shield/accelerator tube assembly. The target was packaged and stored in room P-33A and the other 2 assemblies were wrapped in plastic for storage. In June of 1995 the neutron generator was further disassembled to enable storage in 55 gallon drums and thoroughly surveyed for loose surface contamination. Openings on the disassembled hardware components were closed off using either duct tape or bolted stainless steel flanges to prevent the possible spread of contamination. Significant levels of removable surface contamination could be found on system internal and some external surfaces, up to five hundred thousand disintegrations per minute. Initial analysis of the removable contamination using aluminum absorbers and a Geiger-Meuller tube indicated beta particle or possibly photon emitters with an energy of approximately 180 keV. This apparent radiation energy conflicted with what one would be expected to find, given knowledge of the source material and the possible neutron activated products that would be present in this type of unit. All activation products of neutron generator components, as a result of the exposure to 14 MeV neutrons are short lived, and would have decayed to below detection levels in the period of time since the unit was last operated, a period of approximately six years. This project consists of identifying the nuclide responsible for the apparent radiation energy. Additionally, as a service to San Diego State`s Radiation Safety Office, an estimate of the amount of activity in the unit will be made, as required for future disposal purposes as well as packaging the unit for shipment according to current state and federal regulations.« less