Showing papers by "Kaori Hattori published in 2010"
Boston University1, University of Waterloo2, Perimeter Institute for Theoretical Physics3, Massachusetts Institute of Technology4, Joseph Fourier University5, University of California, Los Angeles6, Occidental College7, University of Pennsylvania8, University of Zaragoza9, University of Sheffield10, Brandeis University11, Harvard University12, Nagasaki Institute of Applied Science13, University of Edinburgh14, University of New Mexico15, University of Huelva16, University of Utah17, University of Nottingham18, Kyoto University19, Lawrence Berkeley National Laboratory20, Temple University21, University of Warwick22, New York University23, Nagoya University24, University of Tokyo25, Saga University26, University of Ioannina27
TL;DR: The case for a dark matter detector with directional sensitivity was presented at the 2009 CYGNUS workshop on directional dark matter detection, and contributions from theorists and experimental groups in the field as mentioned in this paper.
Abstract: We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M.
224 citations
TL;DR: In this article, a direction-sensitive dark matter search experiment at Kamioka underground laboratory with the NEWAGE-0.3a detector was performed, which achieved a new record of 5400 pb for 150 GeV / c 2 WIMPs.
98 citations
01 Nov 2010-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, an 8×8 array of LaBr 3 (Ce) pixel scintillator pixels with a pixel size of 5.8×5.0mm 3 was developed for an electron-tracking Compton camera.
Abstract: We have developed LaBr 3 (Ce) pixel scintillator arrays for an electron-tracking Compton camera (ETCC) that consists of a gaseous time projection chamber (TPC) and the scintillators. The TPC measures the three-dimensional track and energy of a Compton recoil electron, while the scintillators measure the energy and position of the scattered gamma ray. Therefore, the ETCC is able to reconstruct Compton scattering event by event. We adopted LaBr 3 (Ce) scintillators because the angular resolution of the ETCC depends on the energy resolution of the scintillators, and LaBr 3 (Ce) has an FWHM energy resolution of about 3% at 662 keV using a single-anode photomultiplier tube (PMT). We have developed an 8×8 array of LaBr 3 (Ce) scintillator pixels with a pixel size of 5.8×5.8×15.0 mm 3 , which has an FWHM energy resolution of 5.8±0.9% at 662 keV when coupled to a multi-anode PMT (Hamamatsu H8500). The ETCC with the LaBr 3 (Ce) arrays has an FWHM angular resolution of 4.2 ± 0 . 3 ∘ at 662 keV.
13 citations
Patent•
29 Jan 2010
TL;DR: In this article, the authors proposed a method for estimating the position of the collimator in a point response function, based on the position information on the object in a plane view from the vertical direction.
Abstract: PROBLEM TO BE SOLVED: To provide a radiation imaging apparatus which enables acquisition of an excellent reconstructed image even when displacement of a collimator is present, and a method for estimating position of the collimator which is used therefor. SOLUTION: In the radiation imaging apparatus 1 including detectors 21 for measuring radiation, the collimator 26 for limiting the direction of incidence of the radiation and a data processing device 12 with the detectors 21 in a plurality disposed in a through hole 27 of the collimator 26 in a plane view from the vertical direction, the data processing device 12 includes a position information estimating means 12 which estimates position information on the collimator 26 in relation to the detectors 21, a point response function calculating means 12 which calculates a point response function, based on the position information on the collimator 26, and a spatial resolution correcting means 12 which corrects spatial resolution by incorporating the point response function in image reconstruction. COPYRIGHT: (C)2011,JPO&INPIT
4 citations
01 Mar 2010
TL;DR: In this article, a micro-pixel gaseous chamber (μPIC) is used as a thermal neutron imaging detector for applications in small angle neutron scattering (SANS), neutron radiography, and radioactive material detection.
Abstract: A new detector employing the micro-pixel gaseous chamber (μPIC) is currently being developed as a thermal neutron imaging detector for applications in small angle neutron scattering (SANS), neutron radiography, and radioactive material detection. Neutron detection is achieved through the 3He(n, p)3H absorption reaction by adding 3He to the usual Argon-Ethane gas mixture. The μPIC, with a pixel pitch of 400 microns, is coupled with an FPGA-based data acquisition system with a 100 MHz internal clock. This combined system has excellent spatial (< 1mm) and time (10 ns) resolutions and is capable of handling counting rates greater than 5 MHz. These qualities make it well suited to SANS measurements at pulsed neutron sources. Here, we report the performance of a new dedicated μPIC-based neutron imaging detector system along with the results of a test experiment at a small Tandem accelerator-based neutron source currently under development at Kyoto University. This new detector features a 10 × 10 × 5 cm3 active volume and operates at gas pressures up to 2 atm. With this design, we expect a neutron detection efficiency of ∼30% for a gas mixture containing 30% 3He at a total pressure of 2 atm. Additionally, an improved FPGA encoder program allows the simultaneous measurement of the track length and energy deposition, allowing a finer position resolution and strong rejection of the gamma-ray and fast neutron backgrounds.
2 citations
TL;DR: In this paper, a sub-MeV and MeV gamma-ray imaging Compton camera was developed for use in gamma ray astronomy; it consists of a gaseous time-projection chamber (TPC) to convert the Compton scattering events and a scintillator array to absorb photons.
Abstract: We have developed a sub-MeV and MeV gamma-ray imaging Compton camera for use in gamma-ray astronomy; it
consists of a gaseous time-projection chamber (TPC) to convert the Compton scattering events and a scintillator array to
absorb photons. The TPC measures the energy and three-dimensional tracks of Compton-recoil electrons, while the pixel
scintillator arrays measure the energy and positions of scattered gamma rays. Therefore, our camera can reconstruct the
incident gamma rays, event by event, over a wide field of view of approximately 3 str. We are now developing a
Compton camera for a balloon-borne experiment.