摘要:

The feasibility of a large-volume liquid xenon Compton telescope based on full event imaging in a time projection chamber has been demonstrated with the development of the balloon-borne instrument LXeGRIT. With its 400 cm2sensitive area and 7 cm drift gap, the liquid xenon detector images &ggr;-rays in the energy range from 200 keV to 25 MeV. The precise 3-dimensional localization of &ggr;-ray interactions within the sensitive volume provides excellent background reduction capabilities. Together with the large efficiency of a homogeneous detector volume, LXeGRIT addresses the primary instrumental limitations encountered in this energy band. Following engineering tests at balloon altitude in 1997, LXeGRIT has been upgraded with a new trigger and data acquisition system, integrated with the existing readout electronics. Enhanced data transfer capability and onboard data storage were also implemented. LXeGRIT was successfully flown from Ft. Sumner, NM on May 7, 1999. The instrument worked as expected at balloon altitude. The large amount of data gathered during the 9.5 h flight are currently being analyzed. We describe the instrument and present some results from calibration data and preliminary results from the flight. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303308

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

TIGRE is an advanced telescope for gamma-ray astronomy with a few arcmin resolution. From 0.3 to 10 MeV it is a Compton telescope. Above 1 MeV, its multi-layers of double sided silicon strip detectors allow for Compton recoil electron tracking and the unique determination for incident photon direction. From 10 to 100 MeV the tracking feature is utilized for gamma-ray pair event reconstruction. Here we present TIGRE energy resolutions, background simulations and the development of the electronics readout system. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303309

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

CIPHER (Coded Imager and Polarimeter for High Energy Radiation) is a hard X and soft &ggr;-ray spectroscopic and polarimetric coded mask telescope based on an array of Cadmium Telluride microspectrometers. The position sensitive detector (PSD) is arranged in 4 modules of32×32crystals, each of2×2&hthinsp;mm2cross section and 10 mm thickness giving a total active area of about 160 cm2. The PSD is actively shielded by CsI crystals on the bottom and sides in order to reduce background and operates over a wide energy range (∼10 keV to 1 MeV). The mask, based on a modified uniformly redundant array (MURA) pattern, is about four times the area of the PSD and, being situated at about 100 cm from the CdTe array top surface, provides a wide field of view. The CIPHER instrument is proposed for a balloon experiment, both in order to assess the performance of such an instrumental concept for a small/medium size satellite (or an external ISS-alpha payload) survey mission and to perform an innovative measurement of the Crab polarization level. CIPHER’s wide field of view allows it to keep a single source within the field of view for a long observation period without requiring a precise pointing system. Herein we describe the instrument design, together with results obtained in our development studies on CdTe detectors. Furthermore we present the expected performance in terms of image and spectral quality (angular and energy resolution) and polarimetric capabilities for an observation of the Crab pulsar from balloon altitudes ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303310

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

MGEANT is a multi-purpose simulation package based on the CERN GEANT package and Program Library. This package allows for the rapid prototyping of a wide variety of gamma-ray detector systems. The two main advantages of this package over standard GEANT simulations are 1) the detector geometry and material data are supplied via input files instead of being hard coded and 2) MGEANT has several built in spectral and beam options including the ability to simulate observations with multiple pointings and diffuse sources. We are currently using MGEANT to produce detailed observation simulations and response matrices for INTEGRAL/SPI. We present a sample of the type of work that has been done at GSFC using MGEANT simulations. This software package is available from our website http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/integral/. ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303311

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

Centaurus A is the nearest active radio galaxy and thus it is the object of many detailed studies. A set of dedicated web based Centaurus A pages has been established in an effort to collect and present all available information and make it available “by a mouse click” at the URL: “http://www.gamma.mpe-garching.mpg.de/∼hcs/Cen-A/.” ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1303312

出版商:AIP    

年代:1900

数据来源: AIP

摘要:

A complete bibliography of all CGRO-COMPTEL related [1] publications has been established and is maintained on WWW accessible pages at the URL: “http://www.gamma.mpe-garching.mpg.de/∼hcs/CBIB/.” ©2000 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1307037

出版商:AIP    

年代:1900

数据来源: AIP