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560
Review of mathematics, numerical factors, and corrections for dark matter experiments based on elastic nuclear recoil
 Astroparticle Physics
, 1996
"... We present a systematic derivation and discussion of the practical formulae needed to design and interpret direct searches for nuclear recoil events caused by hypothetical weakly interacting dark matter particles. Modications to the dierential energy spectrum arise from the Earth's motion, reco ..."
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We present a systematic derivation and discussion of the practical formulae needed to design and interpret direct searches for nuclear recoil events caused by hypothetical weakly interacting dark matter particles. Modications to the dierential energy spectrum arise from the Earth's motion, recoil detection eciency, instrumental resolution and threshold, multiple target elements, spindependent and coherent factors, and nuclear form factor. We discuss the normalization and presentation of results to allow comparison between dierent target elements and with theoretical predictions. Equations relating to future directional
Mooij, Extended Abstracts of
 1993 Int. Conf. on Solid State Devices and Material
, 1993
"... social upheaval and an unsynpathttlc press at ho«t ( hava crtattd ««hat has bttn called "An Aray In Anguish. " This assay first e»aalnos tha Issues that have contributed to the current l^age of the US Anay. Recognition of the problem and current corrective actions are next discussed. Las ..."
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Cited by 40 (3 self)
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social upheaval and an unsynpathttlc press at ho«t ( hava crtattd ««hat has bttn called "An Aray In Anguish. " This assay first e»aalnos tha Issues that have contributed to the current l^age of the US Anay. Recognition of the problem and current corrective actions are next discussed. Lastly, proposals that would rejuvenate the Army fron within and polish Its Image are Introduced. Throughout the history of the Army, professionalism has been the single most Important Ingredient In Its organization and operation. An Improved Image will require an extra portion of professionalism. 4
EVENTS RECONSTRUCTION IN 3D POSITION SENSITIVE CdZnTe GAMMARAY SPECTROMETERS
"... The wide band gap semiconductor material CdZnTe has long been of interest for gammaray spectroscopy at room temperature. Despite the resolution improvement using singlepolarity charge sensing techniques, the variations in detector response, such as the peripheral asymmetry in coplanar grids and th ..."
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Cited by 13 (1 self)
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The wide band gap semiconductor material CdZnTe has long been of interest for gammaray spectroscopy at room temperature. Despite the resolution improvement using singlepolarity charge sensing techniques, the variations in detector response, such as the peripheral asymmetry in coplanar grids and the material nonuniformity can still degrade the energy resolution of large volume CdZnTe detectors. A 3D CdZnTe spectrometer employs a pixellated anode and a conventional planar cathode. The pixel position provides the interaction’s lateral coordinates, while the interaction depths for singlepixel events are derived from the cathode to anode signal ratio. For multiplepixel events, individual electron drift times are recorded to obtain the depth for each interaction. The 3D position sensitivity enables corrections of nonuniform detector response down to the limit of the position resolution over the whole detector volume. This work is the first successful demonstration of 3D position sensing for multiplepixel events, together with singlepixel events, all done through application specific integrated circuits (ASIC). Significant improvements in energy resolutions for both singlepixel and multiplepixel events have been achieved. Various
Liquid xenon detectors for particle physics and astrophysics
 Rev. Mod. Phys.82 (2010) 2053, arXiv:0910.4956 [physics.insdet
"... ar ..."
Identification of LowLevel Point Radiation Sources Using a Sensor Network
"... Abstract—Identification of a lowlevel point radiation source amidst background radiation is achieved by a network of radiation sensors using a twostep approach. Based on measurements from three sensors, the geometric difference triangulation method is used to estimate the location and strength of ..."
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Cited by 11 (4 self)
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Abstract—Identification of a lowlevel point radiation source amidst background radiation is achieved by a network of radiation sensors using a twostep approach. Based on measurements from three sensors, the geometric difference triangulation method is used to estimate the location and strength of the source. Then a sequential probability ratio test based on current measurements and estimated parameters is employed to finally decide: (i) presence of a source with the estimated parameters, or (ii) absence of the source, or (iii) insufficiency of measurements to make a decision. This method achieves the specified levels of false alarm and missed detection probabilities, while ensuring close to minimal number of measurements to reach a decision. This method minimizes the ghostsource problem of the current estimation methods and achieves lower false alarm rate compared to current detection methods. This method is tested and demonstrated using: (a) simulations, and (b) a testbed that utilizes the scaling properties of point radiation sources to emulate high intensity ones that cannot be easily and safely handled in experimentation.
Mean and variance of singles photon counting with deadtime
 Med. Biol
, 2000
"... The statistics of photon counting by systems affected by deadtime are potentially important for statistical image reconstruction methods. We present a new way of analyzing the moments of the counting process for a counter system affected by various models of deadtime related to PET and SPECT imagin ..."
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Cited by 9 (4 self)
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The statistics of photon counting by systems affected by deadtime are potentially important for statistical image reconstruction methods. We present a new way of analyzing the moments of the counting process for a counter system affected by various models of deadtime related to PET and SPECT imaging. We derive simple and exact expressions for the first and second moments of the number of recorded events under various models. From our mean expression for a SPECT deadtime model, we derive a simple estimator for the actual intensity of the underlying Poisson process; simulations show that our estimator is unbiased even for extremely high count rates. From this analysis, we study the suitability of the Poisson statistical model assumed in most statistical image reconstruction algorithms. For systems containing "modules" with several detector elements, where each element can cause deadtime losses for the entire module, such as block PET detectors or Anger cameras, the Poisson statistical model appears to be adequate even in the presence of deadtime losses.
Localization Under Random Measurements with Application to Radiation Sources
"... Abstract—We consider the problem of estimating the location of a target on a plane using random measurements of sensors ’ distancedifferences to the target. The linear algebraic solution to this problem becomes incomplete under random measurement errors, while the geometric method that always retur ..."
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Cited by 7 (2 self)
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Abstract—We consider the problem of estimating the location of a target on a plane using random measurements of sensors ’ distancedifferences to the target. The linear algebraic solution to this problem becomes incomplete under random measurement errors, while the geometric method that always returns a solution has been developed only for 3sensor configurations. We present three methods to extend the geometric method to a larger number of sensors, and compare their performance using simulations. We then consider the case where measurements are not timesynchronized but are independently collected over the same timewindow, and present a simulationbased comparison of two localization methods based on mean of estimators and means of measurements, respectively. We describe a method for localizing point radiation sources from intensity measurements which uses the localization as a component. Based on simulation and testbed results, our estimators ’ performance improves with the number of sensors, and with mean of estimators method offer a better overall performance. Index Terms—Distancedifference, point radiation source, detection and localization. I.
The cosmicray soil moisture observing system COSMOS: a noninvasive, intermediate scale soil moisture measurement network
, 2010
"... All intext references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. ..."
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Cited by 7 (4 self)
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All intext references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Gammaray imaging and polarization measurement using 3D positionsensitive CdZnTe detectors
, 2006
"... To my family. ii ACKNOWLEDGEMENTS First and foremost I would like to express my gratitude to my advisor, Prof. Zhong He, for all his guidance and support throughout my graduate career. Words can not describe my appreciation to him. This work would not have been possible without his support. I would ..."
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To my family. ii ACKNOWLEDGEMENTS First and foremost I would like to express my gratitude to my advisor, Prof. Zhong He, for all his guidance and support throughout my graduate career. Words can not describe my appreciation to him. This work would not have been possible without his support. I would also like to thank Prof. Glenn Knoll, who was always overlooking my research progress and gave me encouragements. I am thankful to Prof. James Holloway and Prof. Jianjun Shi for serving on my dissertation committee and providing many thoughtful comments and suggestions about this thesis. I appreciate Dr. Feng Zhang for his marvelous work on the 3D CdZnTe detectors. Without his solid development on the detector hardware, all my work would only have been pictures on paper. Many thanks are due to Dr. Carolyn Seifert. Her previous work built a solid foundation for the gammaray Compton imaging using a single 3D CdZnTe detector. It was her pioneer work that led me into this interesting
Semiconductor scintillator for 3dimensional array of radiation detectors, Future Trends
 in Microelectronics: Unmapped Roads, Wiley Interscience
, 2010
"... There are two large groups of solidstate radiation detectors, which dominate the area of ionizing radiation measurements, scintillation detectors and semiconductor diodes. The scintillators detect highenergy radiation through generation of light which is subsequently registered by a photodetector ..."
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Cited by 7 (4 self)
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There are two large groups of solidstate radiation detectors, which dominate the area of ionizing radiation measurements, scintillation detectors and semiconductor diodes. The scintillators detect highenergy radiation through generation of light which is subsequently registered by a photodetector that converts light into an