E. Bloom

Pre-launch estimates for GLAST sensitivity to dark matter annihilation signals

We investigate the sensitivity of the Gamma-ray Large Area Space Telescope (GLAST) for indirectly detecting weakly interacting massive particles (WIMPs) through the γ-ray signal that their pair ann ...

Results from the Beam Test of the Engineering Model of the GLAST Large Area Telescope

This paper describes the results of a beam test using the Engineering Model of the GLAST Large Area Telescope, which was installed in a beam of positrons, hadrons and tagged photons at SLAC. The performance of the four subsystems, Anti Coincidence Detector, Silicon Tracker, Calorimeter and Data Acquisition will be described.

The silicon tracker of the beam test engineering model of the GLAST large-area telescope

The silicon tracker for the engineering model of the GLAST Large Area Telescope(LAT) has at least two unique features: it employs self triggering readout electronics, dissipating less than 200 mu-W per channel and to date represents the largest surface of silicon microstrip detectors assembled in a tracker (2.7 m{sup 2}). It demonstrates the feasibility of employing this technology for satellite based experiments, in which low power consumption, large effective areas and high reliability are required. This note describes the construction of this silicon tracker, which was installed in a beam test of positrons, hadrons and tagged photons at SLAC in December of 1999 and January of 2000.

The assembly of the silicon tracker for the GLAST beam test engineering model

Abstract The silicon tracker for the engineering model of the GLAST Large Area Telescope (LAT) to date represents the largest surface of silicon microstrip detectors assembled in a tracker (2.7xa0m 2 ). It demonstrates the feasibility of employing this technology for satellite based experiments, in which large effective areas and high reliability are required. This note gives an overview of the assembly of this silicon tracker and discusses in detail studies performed to track quality assurance: leakage current, mechanical alignment and production yields.

Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity

The LAT Dark Matter and New Physics Working group has been developing approaches for the indirect astrophysical detection of annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP). The annihilation of two WIMPs usually results in the production of many high energy gamma rays (>1 GeV) that can be well measured in the GLAST LAT if present. There is also the possibility to observe γ lines from annihilation into γγ and or γZ final states. In popular SUSY theories these line decays occur at the 10−4 to 10−2 branching fraction level. Estimates of LAT sensitivity (at 5σ above background) and upper limits (upper limit at the 95% confidence level) to these WIMP lines will be presented. These sensitivities are given in photons/cm2/sec/sr and so do not depend on the WIMP models. However, they do depend on the diffuse background model. The latter is derived from GALPROP based on EGRET and other data in the EGRET energy ...

Novel technique for monitoring the performance of the LAT instrument on board the GLAST satellite

The Gamma‐ray Large Area Space Telescope (GLAST) is an observatory designed to perform gamma‐ray astronomy in the energy range 20 MeV to 300 GeV, with supporting measurements for gamma‐ray bursts from 10 keV to 25 MeV. GLAST will be launched at the end of 2007, opening a new and important window on a wide variety of high energy astrophysical phenomena. The main instrument of GLAST is the Large Area Telescope (LAT), which provides break‐through high‐energy measurements using techniques typically used in particle detectors for collider experiments. The LAT consists of 16 identical towers in a four‐by‐four grid, each one containing a pair conversion tracker and a hodoscopic crystal calorimeter, all covered by a segmented plastic scintillator anti‐coincidence shield. The scientific return of the instrument depends very much on how accurately we know its performance, and how well we can monitor it and correct potential problems promptly.We report on a novel technique that we are developing to help in the characterization and monitoring of LAT by using the power of classification trees to pinpoint in a short time potential problems in the recorded data. The same technique could also be used to evaluate the effect on the overall LAT performance produced by potential instrumental problems.The Gamma‐ray Large Area Space Telescope (GLAST) is an observatory designed to perform gamma‐ray astronomy in the energy range 20 MeV to 300 GeV, with supporting measurements for gamma‐ray bursts from 10 keV to 25 MeV. GLAST will be launched at the end of 2007, opening a new and important window on a wide variety of high energy astrophysical phenomena. The main instrument of GLAST is the Large Area Telescope (LAT), which provides break‐through high‐energy measurements using techniques typically used in particle detectors for collider experiments. The LAT consists of 16 identical towers in a four‐by‐four grid, each one containing a pair conversion tracker and a hodoscopic crystal calorimeter, all covered by a segmented plastic scintillator anti‐coincidence shield. The scientific return of the instrument depends very much on how accurately we know its performance, and how well we can monitor it and correct potential problems promptly.We report on a novel technique that we are developing to help in the chara...