A beam test of GLAST (Gamma-ray Large Area Space Telescope) components was performed at the Stanford Linear Accelerator Center in October, 1997. These beam test components were simple versions of the planned flight hardware. Results on the performance of the tracker, calorimeter, and anti-coincidence charged particle veto are presented.
Observations of cosmic-ray electrons and positrons have been made with a new balloon-borne detector, HEAT (the " High-Energy Antimat-ter Telescope "), first flown in 1994 May from Fort Sumner, NM. We describe the instrumental approach and the data analysis procedures, and we present results from this flight. The measurement has provided a new determination… (More)
We discuss a search for aperiodic millisecond variability in the integrated 1 to 25 keV X-ray region of Cyg X-1. We have examined HEAO A-1 archival data and RXTE guest observer data for indications of excess power above the Poisson noise oor using the relative integral power analysis and the Fourier transform method. We present results that are in… (More)
We present a new measurement of the cosmic-ray positron fraction e + =(e + + e) obtained from the rst balloon ight of the High Energy Antimatter Telescope (HEAT). Using a magnet spectrometer combined with a transition radiation detector, an electromagnetic calorimeter, and time-of-ight counters we have achieved a high degree of background rejection. Our… (More)
The HEAT (High Energy Antimatter Telescope) instrument was successfully own by high altitude balloon in May 1994. HEAT combines a new magnet spectrometer, comprised of a two-coil superconducting magnet and precision drift tube hodoscope, with a transition radiation detector and electromagnetic shower counter for particle identiication. Flight data are… (More)
Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Ft. Sumner, New Mexico in 1994, and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight from Lynn Lake, Manitoba in 1995… (More)
The High-Energy Antimatter Telescope (HEAT) instrument has been own successfully by high-altitude balloon in 1994 and 1995, in a connguration optimized for the detection and identiication of cosmic-ray electrons and positrons at energies from about 1 GeV up to 50 GeV and beyond. It consists of a two-coil superconducting magnet and a precision drift-tube… (More)