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A method is proposed for performing organic/inorganic materials discrimination using an x-ray forward/backscatter scanner. The method is demonstrated using a commercially available personnel security-screening system and requires only image post processing
Leticia S. Pibida, Ronaldo Minniti, Larry L. Lucas, C M. O'Brien
In this work we studied the response of two different Victoreen® instruments as a function of the exposure rate, the instrument orientation and photon energy. The rate dependence for both instruments is of the order of 8 % over the range of exposure rates
An indirect comparison of the standards for air kerma of the National Institute of Standards and Technology (NIST), USA, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in September 2011
Thomas R. Gentile, M E. Hayden, P.J. Nacher, A K. Petukhov, B Saam, T G. Walker
H.H. Chen et al [1] claim that adding 4He to spin-exchange optical pumping (SEOP) cells confines 3He atoms to a diffusion-limited region, which effectively reduces the wall relaxation factor X. Here X is a phenomenological parameter used to characterize
Ronaldo Minniti, Claudia Brunner, Stanley H. Stern, Marie I. Parry, Kish Chakrabarti
The purpose of this work was to measure radiation absorbed dose and its distribution in an anthropomorphic head phantom under clinically representative scan conditions in three widely-used computed tomography (CT) scanners, and to relate those dose values
Daniel S. Hussey, Elias M. Baltic, Kevin J. Coakley, David L. Jacobson
This in-situ study examines the water content in polymer electrolyte fuel cells (PEFCs) using neutron radiography. Various conditions such as different polytetraflouroethylene (PTFE) loadings in the gas diffusion media including the micro-porous layer (MPL
Ronaldo Minniti, Hugo de las Heras Gala, Sean Wilson, Chad Mitchell, Marlene Skopec, Claudia Brunner, Kish Chakrabarti
In this work we relate the CT dose index volume (CTDIvol) readily displayed in all CT units with an actual Peak Skin Dose (PSD) value. Measurements of the CTDI and skin exposure were performed simultaneously using an ionization chamber and radiochromic
Robert D. Horansky, Joel N. Ullom, Michael W. Rabin
There is currently significant interest in using superconducting detectors for measurement of ion kinetic energies. Unprecedented resolution is possible with an order of magnitude improvement over semiconductors. Superconducting detectors are now able to
Several measurements and calculations were performed to illustrate the differences that can be observed in the determination of exposure rate or ambient dose equivalent rate used for testing radiation detection systems against consensus standard. The large
Chukwudi A. Okoro, Lyle E. Levine, Oleg A. Kirillov, Yaw S. Obeng, Ruqing Xu, Jonathan Z. Tischler, Wenjun Liu, Klaus Hummler
We report the first non-destructive, depth resolved determination of the full stress tensor in Cu through-silicon vias (TSVs), using synchrotron based micro-beam X-ray diffraction. Two adjacent Cu TSVs were studied; one deliberately capped with SiO2, the
Qiang NMN Ye, Thomas R. Gentile, Jeffrey R. Anderson, Collin L. Broholm, WangChun Chen, Z DeLand, Ross W. Erwin, C. B. Fu, John E. Fuller III, Aaron V. Kirchhoff, J. A. Rodriguez-Rivera, V. Thampy, T G. Walker, Shannon Watson
We report substantial improvements in a compact wide angle neutron spin filter system that was recently employed on the Multi-Axis Crystal Spectrometer at the Center for Neutron Research at the U.S. National Institute of Standards and Technology. The
Lawrence T. Hudson, John F. Seely, Bruce V. Weber, D. G. Phipps, Nino R. Pereira, D Mosher, K. Slabkowska, M. Polasik, J Rzadkiewicz, S Hansen, Uri Feldman, Joseph W. Schumer
High resolution spectra of the W L transitions in the energy range 8 keV to 12 keV from warm dense plasmas generated by the Naval Research Laboratorys Gamble III pulsed power machine were recorded by a transmission-crystal x-ray spectrometer with ± 2 eV
Lawrence T. Hudson, C T. Chantler, M N. Kinnane, John D. Gillaspy, A.T. Payne, L F. Smale, Albert Henins, Joshua M. Pomeroy, J A. Kimpton, E Takacs, K Makonyi
We find that Epps [1] hypothesis - namely that the current experimental data set is well represented by a small constant or zero offset from the predictions of Artemyev et al. [2] - is not supported by standard statistical analysis. We find that adding
Jeffrey S. Nico, C. D. Bass, E J. Beise, Craig Heimbach, T. Langford
We present the characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% 6Li. We report on its performance in terms of optical properties and neutron response. We
Leticia S. Pibida, Craig Heimbach, Bruce R. Norman, Alan Keith Thompson, Maynard S. Dewey
Initial neutron measurements and calculations were performed to investigate the response of handheld radionuclide identifiers (RIDs) to neutron sources with different moderators/scattering conditions
Two gross count and one radionuclide identification backpack-type radiation detectors (BRDs) were used to validate radiological test requirements listed in the Domestic Nuclear Detection Office (DNDO), Technical Capability Standard (TCS) for BRDs. For this
Svetlana Nour, Kenneth G. Inn, James J. Filliben, Hank dan der Gaast, Lee Chung Men, M.D. Calmet, P Povinec, Y Takata, M. Wisdom, K. Nakamura, Pia Vesterbacka, Ching-Chung Huang, S M. Vakulovsky
A new Shellfish Standard Reference Material (SRM 4358) was developed at the National Institute of Standards and Technology (NIST) via an international intercomparison project that involved 12 laboratories-participants from 9 countries (Table 1). This
Ronald E. Tosh, S Picard, D T. Burns, P Roger, Fred B. Bateman, Huaiyu H. Chen-Mayer
A comparison of the dosimetry for accelerator photon beams was carried out between the National Institute of Standards and Technology (NIST) and the Bureau International des Poids et Mesures (BIPM) in September and October 2010. The comparison was based on
The CIE standardized rectangular-shape UV response functions can be realized only with large spectral mismatch errors. The spectral power-distribution of UV sources is not standardized. Accordingly, the readings of different types of UV meters, even if
This report details analyses in the development of certain correction factors for free-air ionization chambers used by the National Institute of Standards and Technology to realize air kerma for its measurement standards and calibrations of W-anode x-ray
Lawrence T. Hudson, C T. Chantler, Mark N. Kinnane, John D. Gillaspy, A.T. Payne, L F. Smale, Albert Henins, Joseph N. Tan, J A. Kimpton, E Takacs, K Makonyi, Joshua M. Pomeroy
We report the measurement of the w (1s2p 1P1 ! 1s2 1S0) resonance line transition energy in helium-like titanium. Our result, 4749.85(7) eV, deviates from the most recent ab initio prediction by three times our experimental uncertainty and by many times
Jeffrey S. Nico, T E. Chupp, K P. Coulter, R L. Cooper, S. J. Freeman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Hans P. Mumm, Alan K. Thompson, C A. Trull, F. E. Wiefeldt, J. F. Wilkerson
Time-reversal-invariance (T) violation, or equivalently, assuming charge-conjugation-parity-time-reversal (CPT) invariance, CP violation may explain the observed cosmological baryon asymmetry as well as signal physics beyond the Standard Model. In the
This report provides a justification for shielding plutonium sources when testing radiation detection instruments against standard performance requirements and test methods. The use of copper as a shielding material is proposed to provide comparable test
In the June Issue of Medical Physics, Hoppe and Schmidt presented estimates of the organ and effective dose from an x-ray backscatter scan using a Rapiscan Secure 1000 single pose system . The paper presents Monte Carlo modeling results and takes its
Thomas R. Gentile, X Tong, C Y. Jiang, V Lauter, H. Ambaye, D. Brown, L Crow, R J. Goyette, W-T Lee, A. Parizzi
We report on the in-situ polarized 3He neutron polarization analyzer developed for the time-of-flight Magnetism Reflectometer (MAGICS) at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). Using the spin exchange optical pumping