Details of the balloon and launch operations
Launch site: Scientific Flight Balloon Facility, New Mexico, US
Launch team: National Scientific Balloon Facility (NSBF)
Balloon: Open balloon (zero pressure) Raven 4.0 - 113.000 m3 - SF3-4.001-.8/.8-NA
Serial number: R4.001-1-09
Flight identification number: 441N
Campaign: No Data
Payload weight: 1212 lbs
Gondola weight: -
Overall weight: -
Description of the payload or experiment
HEXIS (High Energy X-ray Imaging Spectrometer)
Responsable institution: University of California. San Diego
Principal Investigator: Dr. James L. Matteson
The High Energy X-ray Imaging Spectrometer (HEXIS) program is developing position sensitive Cadmium Zinc Telluride (CZT) X-Ray detectors for use in X-ray astronomy and mission concepts for both balloon and satellite based telescopes.
In a balloon based version of HEXIS, the scientific objectives are to study hot plasmas, non-thermal and accelerated particles, and nuclear and electromagnetic processes in the hard X-ray regime (20-200keV). These processes occur in astrophysical source regions characterized by compact objects, high magnetic fields, high gravitational potentials and general relativistic phenomena. Such sources are known to occur in X-ray pulsars, black hole candidates, active galactic nuclei (AGN) and regions emitting nucleosynthetic gamma rays. CZT detectors are capable of very fine position resolution, to detect this sources.
Performance in flight and data obtained
As part of the program development, this was the first balloon flight carriying both a cross strip and a standard planar detector, of dimensions 12 mm x 12 mm x 2 mm, were flown in various passive shield configurations with their cathodes facing earthward.
These detectors, along with the HV bias supply were housed in an aluminum pressure vessel.
This series of balloon flights had significantly improved the understanding of the background properties of CZT, including background rejection techniques based on the physics of CZT detectors. Shielding effects are being extensively studied with this unique data set comprising seven different shielding configurations using the same two detectors and readout systems. These data will contribute great insight into optimal shielding for the next generation hard X-ray instruments.
External references and bibliographical sources
- HEXIS web site Washington University in St. Louis
- Background Studies of a Position Sensitive CdZnTe X-ray Detector at Balloon Altitudes Proceedings of the 26th International Cosmic Ray Conference. August 17-25, 1999. Salt Lake City, Utah, USA.
- High altitude balloon flight of CdZnTe detectors for high energy X-ray astronomy Proc. SPIE, 3445, p. 169-183, 1998.
- High altitude balloon flight of CdZnTe detectors for high energy X-ray astronomy Proc. SPIE, 3445, p. 169-183, 1998.
- High altitude balloon flight of CdZnTe detectors for high energy X-ray astronomy Part II Proc. SPIE, 3765, pgs. 397-406, 1999.
