M.H. Putnam

Idaho National Laboratory, Айдахо-Фолс, Idaho, United States

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Publications (17)13.44 Total impact

  • R.C. Greenwood · R.G. Helmer · M.H. Putnam · K.D. Watts
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    ABSTRACT: A total absorption γ-ray spectrometer coupled to the 252Cf-based INEL ISOL facility has been used in a program of systematic study of the distributions of β−-decay intensities of fission-product radionuclides. Cascade-summed γ-ray spectra measured with the system have been compared with the spectrum simulated from the corresponding decay schemes, as a test of the completeness and correctness of these schemes. New β−-decay intensity distributions have been deduced for the decay of these radionuclides. Radionuclides which have been studied in this manner include 89Rb, 90gRb, 90mRb, 91Rb, 93Rb, 93Sr, 94Sr, 94Y, 95Sr, 95Y, 138gCs, 138mCs, 139Cs, 140Cs, 141Cs, 141Ba, 142Ba, 142La, 143Ba, 143La, 144Ba, 144La, 145Ba, 145La, 145Ce, 146Ce, 146Pr, 147Ce, 147Pr, 148Ce, 148Pr (2.0 min), 148Pr (2.27 min), 149Pr, 149Nd, 151Pr, 151Nd, 152Nd - 152Pm (4.1 min.), 153Nd, 153Pm, 154Nd, 154Pm (1.7 min), 155Nd, 155Pm, 156Pm, 157Pm, 157Sm, 158Sm, and 158Eu.
    No preview · Article · May 1997 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R.C. Greenwood · M.H. Putnam · K.D. Watts
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    ABSTRACT: The final set of results of “ground-state” β−-branching intensities obtained in a program of systematic study of those regions of the fission-product nuclides accessible to investigation using the 252Cf-based INEL ISOL facility are presented. A total absorption γ-ray spectrometer, operating in a 4πγ-β coincidence mode, was used to obtain these “ground-state” β−-branching intensities; where here the “ground-state” is defined to include all states below a selected γ-ray discriminator level. Results obtained for 89Rb, 90gRb, 91Rb, 93Rb, 93Sr, 94Sr, 94Y, 95Sr, 95Y, 140Cs, 142La, 143Ba, 143La, 144Ba, 144La, 145Ba, 145La, 146Ce, 146Pr, 147Ce, 147Pr, 148Ce, 148Pr, (2.27 min), 149Pr, 149Nd, 151Pr, 151Nd, 152Pm (4.1 min), 153Nd, 155Nd, 157Pm, 157Sm, 158Sm and 158Eu are presented and compared with existing published data.
    No preview · Article · Aug 1996 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
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    ABSTRACT: The newest member of a series of computer programs developed at the INEL for analysis of gamma-ray spectra from Ge semiconductor detectors is GAUSS IX. This program makes use of the computational routines of GAUSS VII in an interactive structure. The interactive features are implemented with OSF/Motif and the X Window System. This interactive version can dramatically decrease the turnaround time for spectral analyses, especially when the user needs to refit some of the peaks with specially-chosen fitting parameters. The graphic features increase the opportunity for detecting patterns and anomalies in the spectral analyses. The user of this program can set up the analysis parameters (i.e., peaks, peak regions, etc.) interactively via window dialogs. The user can interactively display and review the results, selectively re-fit peaks, and save or purge the results, as appropriate. The spectral displays can include the spectral data, peak locations, peak fitting regions, fit curves, and background curves; and the display is completely zoomable, scrollable, and resizable
    No preview · Article · Sep 1995 · IEEE Transactions on Nuclear Science
  • R. C. Greenwood · M. H. Putnam · K. D. Watts
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    ABSTRACT: The utility of the method using a total absorption γ-ray spectrometer system, operating in the 4 πγ-β coincidence mode, to measure ground-state β−-branching intensities of deformed rare-earth fission-product nuclei is discussed. For such nuclei it is demonstrated that, given sufficient information concerning the lower excitation states being populated and their de-excitation modes, precise values can still be obtained for their “ground-state” β−-branching intensities; where here the “ground-state” is defined to include both the true ground state and all excited states below a selected γ-ray discriminator level. Results obtained for 153Nd, 153Pm, 154Nd, 154Pm(1.7 min), 155Pm, 156Pm, 157Pm, 157Sm and 158Sm are presented and compared with existing published data.
    No preview · Article · Mar 1995 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R.G. Helmer · M.H. Putnam · R.C. Greenwood · H. Willmes
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    ABSTRACT: A total absorption γ-ray spectrometer (TAGS), based on a 25.4-cm diameter × 30.5-cm long NaI(Tl) well detector, has been developed at the INEL on-line isotope separator facility. A Si detector in the well of the NaI(Tl) detector allows one to collect β-particle-gated coincidence γ spectra in addition to singles γ spectra. From the analysis of these total absorption γ-ray spectra, β−-decay intensity distributions are obtained. The analysis methodology is based on response functions that simulate the response of the NaI(Tl) detector to the γ-rays and electrons (including external bremsstrahlung) from a radioactive source in the detector well. These response functions are computed with a Monte Carlo photon and electron transport code. This methodology has been completely upgraded since it was first developed and now provides very good simulations of both singles and coincidence spectra. As an example of the application of this methodology, the Iβ distribution for the decay of 141Cs is determined from the TAGS spectra.
    No preview · Article · Jan 1995 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
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    ABSTRACT: PASS (Photon Analysis Spectrometer System) is a pulser-equipped, extended range, thin-window, Ge detector spectrometer that is capable of automatically measuring radionuclide activity concentrations in up to 100 samples per day at remediation sites. No operator intervention is required after the counting queue for the sample changer has been setup. Actinides are measured from L X-rays following α decay such as and 241Am → 237Np and from low-energy γ-rays by spectral component analysis. Activation, fission products and a few actinides (e.g., 241Am) are measured from their characteristic γ-ray emission by fitting the associated peaks. Pulses from a precision, dual-energy pulser can be used to determine the energy scale, provide documentation of the data quality, and provide a correction for pulse pileup. Soil, smear, and air particulate samples can be counted. For an 11-g sample counted for 15 min the lower-limits-of-detection are 50, 1, and 5 pCi/g for plutonium, americium, and several γ-ray emitting radionuclides, respectively.
    No preview · Article · Dec 1994 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R.G. Helmer · R.C. Greenwood · M.H. Putnam · K.D. Watts
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    ABSTRACT: A total absorption γ-ray spectrometer has been developed on the 252Cf-based INEL ISOL facility and is being used in a program of measurements of β−-decay intensity distributions of short-lived fission-product nuclei. Spectra for 139Cs and 140Cs have been measured and compared with those simulated for the published decay schemes as a test of the completeness and correctness of these schemes. New β−-intensity distributions have been deduced for the decay of these isotopes.
    No preview · Article · Dec 1994 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R. G. Helmer · R. C. Greenwood · K. D. Watts · M. H. Putnam
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    ABSTRACT: A total absorption gamma-ray spectrometer (TAGS) has been used to measure the summed gamma-ray spectra for several fission products. A Si detector was used to collect beta-particle-gated coincidence TAGS spectra. This system has been used to measure the coincidence spectra for 138-141Cs. The analyses of these spectra are based on response functions for monoenergetic gamma rays and electrons that were computed with a Monte Carlo code. Beta-feeding distributions as a function of the excitation energy of the level have been deduced.
    No preview · Article · Jan 1994 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R. C. Greenwood · M. H. Putnam
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    ABSTRACT: A beta-gamma coincidence spectrometer has been developed, in association with the INEL ISOL facility, to allow beta- end-point energies to be measured for short-lived fission-product isotopes. In this spectrometer a 200 mm2 × 10 mm planar intrinsic Ge detector, in a cryostat with a thin Be window and integrally mounted into the ISOL vacuum system, is used to measure the beta- spectra. A feature of the analysis codes used to unfold these measured beta- spectra is the use of a complete library of electron response functions generated with a Monte Carlo electron and photon transport code. With this system, beta- end-point energies have been measured and Qbeta values deduced, for 32P, 90Y, 140Cs, 151Pr, 153Nd, 153Pm, 154Pm (1.7 min), 155Nd, 155Pm, 155Sm, 157Sm and 158Sm.
    No preview · Article · Dec 1993 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • [Show abstract] [Hide abstract]
    ABSTRACT: A total absorption γ-ray spectrometer (TAGS), based on a 25.4 cm diameter × 30.5 cm long NaI(Tl) well detector, has been developed at the INEL on-line isotope separator facility. A Si detector in the well of the NaI(Tl) detector allows one to collect β-particle-gated coincidence spectra as well as singles spectra. With this system, measurements of the total absorption spectra have been made for a number of fission product nuclei. The analysis of the measured spectra is based on response functions for single γ rays that are computed with a Monte Carlo code. Routines have been written to use these response functions to simulate the response to a cascade of several γ rays and by extension to a whole decay scheme. The bremsstrahlung from a ground-state β branch can also be simulated. The quality of the simulation is demonstrated for test spectra of 137Cs, 24Na, 60Co, and 110mAg. As examples of the operation of this system, the measurements and analyses of the β-decay feeding distributions are described for the decay of 141Ba, 139Cs and 140Cs.
    No preview · Article · May 1992 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R.J. Gehrke · M.H. Putnam · S.G. Goodwin · R.L. Kynaston
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    ABSTRACT: A technique has been developed to rapidly measure the presence of plutonium in soils, filters, smears, and glass waste forms by measuring the uranium L-shell x-ray emissions associated with the decay of plutonium. In addition, the technique can simultaneously acquire spectra of samples and automatically analyze them for the amount of americium, and gamma-ray emitting activation and fission products present. The samples are counted with a large area, thin-window, n-type Ge spectrometer which is equally efficient for the detection of low energy x-rays (>10 key), as well as high-energy gamma rays (>1 MeV). A 8192-channel analyzer is used to acquire the entire photon spectrum at one time. A dual-energy, time-tagged pulser, that is injected into the test input of the preamplifier to monitor the energy scale, detector resolution, and pulse pile-up will be installed in FY-92. The L x-ray portion of each spectrum is analyzed by a linear least-squares spectral fitting technique originally developed for the analysis of spectra from NaI(Tl) detectors. The gamma-ray portion of each spectrum is analyzed by a standard Ge gamma-ray analysis package. Detection limits (also referred to as lower limits of detection) for plutonium in contaminated soils that have been achieved by this technique are reported.
    No preview · Article · Apr 1992
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    ABSTRACT: A total absorption gamma-ray spectrometer (TAGS), based on a large NaI(Tl) detector, has been developed at the INEL ISOL facility. With this system measurements of total absorption spectra for 138–144Cs, 141,142Ba, 142–145La, and 145Ce have been made. From these spectra we will deduce the beta-decay feeding distributions as a function of the daughter level energy.
    No preview · Article · Jan 1992
  • R. G. Helmer · M. H. Putnam · C. M. McCullagh
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    ABSTRACT: This review will describe the various features that are useful in a general-purpose computer program to analyze gamma-spectra from Ge detectors. An INEL code, GAUSS VIII, is used as an example of such a program. This discussion assumes that the goal of the analysis is to determine the activities of the nuclides present for a number of spectra (i.e., production analysis) and that no specialized treatment is given to any particular spectrum. In order to analyze a gamma-ray spectrum in this way, one needs to carry out the following four general functions: (1) calibration of peak energies and widths; (2) a first analysis of spectrum to determine the energies and areas of the peaks and the nuclides that may be present; (3) a second analysis of spectrum to determine the areas of the stronger peaks associated with the identified nuclides but that were not found in the first spectral analysis; and (4) nuclide activity calculations. Some desirable features related to these four areas are discussed. Current address: AT&T Bell Laboratories, Naperville, Illinois 60566, USA.
    No preview · Article · Jan 1986 · Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment
  • R.G. Helmer · M.H. Putnam

    No preview · Article · Dec 1971
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    ABSTRACT: In recent years, the use of the mass separation technique coupled on-line to a source of fission product nuclides has provided a wealth of new information on the nuclear decay properties of such nuclides. In addition to their relevance in basic studies of nuclear properties of neutron-rich nuclei, the fission product nuclides as a group, because of their intimate link with energy production in fission reactors, occupy a unique position in the field of applied nuclear decay data. Further, in addition to their critical role in nuclear reactor technology (decay heat source term, environmental concerns, etc.), such data have important applications in astrophysical calculations involving the rapid neutron capture process (r-process) of elemental synthesis in stellar environments. The scope of the nuclear decay data measurements being undertaken using the Idaho National Engineering Laboratory's (INEL) isotope separation on-line (ISOL) facility is focused on a systematic study of the gross nuclear decay properties of short-lived fission product isotopes, i.e., ground-state half-lives, beta-decay energies and beta-decay feeding (or beta-strength) distributions. In this paper, the authors discuss the results of new measurements of beta-decay energies and feeding distributions.
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  • R. G. Helmer · M. H. Putnam
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    ABSTRACT: GAUSS5 is used to determine gamma-ray energies and intensities from spectra obtained with a Ge(Li) detector and a multichannel pulse-height analysis system.IBM360/75; FORTRAN IV; OS/360 MVT; One 9-track tape for spectral library and four disks, a printer and card punch.
    No preview · Article ·
  • C. W. Reich · R. G. Helmer · M. H. Putnam

    No preview · Article ·

Publication Stats

166 Citations
13.44 Total Impact Points

Institutions

  • 1995
    • Idaho National Laboratory
      Айдахо-Фолс, Idaho, United States
    • Idaho National Laboratory
      Айдахо-Фолс, Idaho, United States