skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Directional Gamma Detection from Occlusion and Crosstalk

 [1];  [1];  [2];  [2]
  1. National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Special Technology Lab
  2. H3D
Publication Date:
Research Org.:
Nevada Test Site/National Security Technologies, LLC (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20); USDOE National Nuclear Security Administration, Office of Defense Nuclear Nonproliferation Research and Development (NA-22)
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: 2017 Nuclear Security Applications Research and Development (NSARD) Portfolio Review, April 4-6, 2017, US DOE, National Nuclear Security Administration Nevada Field Office, North Las Vegas, NV
Country of Publication:
United States

Citation Formats

Trainham, Clifford, Nystrom, Eric, Kaye, Willy, and Jaworksi, Jason. Directional Gamma Detection from Occlusion and Crosstalk. United States: N. p., 2017. Web.
Trainham, Clifford, Nystrom, Eric, Kaye, Willy, & Jaworksi, Jason. Directional Gamma Detection from Occlusion and Crosstalk. United States.
Trainham, Clifford, Nystrom, Eric, Kaye, Willy, and Jaworksi, Jason. Tue . "Directional Gamma Detection from Occlusion and Crosstalk". United States. doi:.
title = {Directional Gamma Detection from Occlusion and Crosstalk},
author = {Trainham, Clifford and Nystrom, Eric and Kaye, Willy and Jaworksi, Jason},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Apr 04 00:00:00 EDT 2017},
month = {Tue Apr 04 00:00:00 EDT 2017}

Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Energy asymmetry of inter-detector crosstalk from Compton scattering can be exploited to infer the direction to a gamma source. A covariance approach extracts the correlated crosstalk from data streams to estimate matched signals from Compton gammas split over two detectors. On a covariance map the signal appears as an asymmetric cross diagonal band with axes intercepts at the full photo-peak energy of the original gamma. The asymmetry of the crosstalk band can be processed to determine the direction to the radiation source. The technique does not require detector shadowing, masking, or coded apertures, thus sensitivity is not sacrificed to obtainmore » the directional information. An angular precision of better than 1° of arc is possible, and processing of data streams can be done in real time with very modest computing hardware.« less
  • The Relativistic Heavy Ions Collider (RHIC) would benefit from improved beam position measurements near the interaction points that see both beams, especially as the tolerances become tighter when reducing the beam sizes to obtain increased luminosity. Two limitations of the present beam position monitors (BPMs) would be mitigated if the proposed approach is successful. The small but unavoidable cross-talk between signals from bunches traveling in opposite directions when using conventional BPMs will be reduced by adopting directional BPMs. Further improvements will be achieved by cancelling residual cross-talk using pairs of such BPMs. Appropriately delayed addition and integration of the signalsmore » will also provide pulses with relatively flat maxima that will be easier to digitize by relaxing the presently very stringent timing requirements.« less
  • The National Security Technologies, LLC, Remote Sensing Laboratory has recently used an array of six small-footprint (1-inch diameter by 3-inch long) cylindrical crystals of thallium-doped sodium iodide scintillators to obtain angular information from discrete gamma ray–emitting point sources. Obtaining angular information in a near-field measurement for a field-deployed gamma sensor is a requirement for radiological emergency work. Three of the sensors sit at the vertices of a 2-inch isosceles triangle, while the other three sit on the circumference of a 3-inch-radius circle centered in this triangle. This configuration exploits occlusion of sensors, correlation from Compton scattering within a detector array,more » and covariance spectroscopy, a spectral coincidence technique. Careful placement and orientation of individual detectors with reference to other detectors in an array can provide improved angular resolution for determining the source position by occlusion mechanism. By evaluating the values of, and the uncertainties in, the photopeak areas, efficiencies, branching ratio, peak area correction factors, and the correlations between these quantities, one can determine the precise activity of a particular radioisotope from a mixture of radioisotopes that have overlapping photopeaks that are ordinarily hard to deconvolve. The spectral coincidence technique, often known as covariance spectroscopy, examines the correlations and fluctuations in data that contain valuable information about radiation sources, transport media, and detection systems. Covariance spectroscopy enhances radionuclide identification techniques, provides directional information, and makes weaker gamma-ray emission—normally undetectable by common spectroscopic analysis—detectable. A series of experimental results using the concept of covariance spectroscopy are presented.« less