Below is a listing of major astrophysics research programs at UNH. Most of these programs involve the development and operation of new detectors as components of balloon-borne experiments or as components of satellite experiments. In some cases, we are working on the development of technologies (such as CdZnTe or valanche photodiode detectors) that may have uses in several different types of experiments. In one case (CATSAT), the hardware development encompasses an entire satellite. Programs involving the development of flight hardware for either balloon or satellite missions are generally supported by NASA. Some of our programs (such as the ground level neutron monitors) involve ground-based detector systems. Ground-based programs are generally supported by NSF funding. In addition to the hardware development activities (and the associated analysis of scientific results), there are several programs which involve the analysis of public data from experiments that did not involve hardware development at UNH. These are also summarized below.

CdZTe Detector Development

UNH has been a leader in the development of CdZnTe strip detector technology for use in space-based applications. These detectors can be used to measure X-rays and gamma-rays with unprecendented spatial resolution and with unsurpassed energy resolution at room temperatures. This development work has been motivated both for use in coded aperture imaging systems (such as MARGIE) and in the next-generation Compton telescope systems (such as TIGRE).

APD Detector Development

UNH has been working closely with colleagues at Radiation Monitoring Devices Inc. to evaluate the feasibility of their avalanche photodiode arrays for use in high energy astrophysics applications. Most of the work to date has concentrated on their use as readout devices for scintillation fibers, as part of the SONTRAC development effort.

COMPTEL - The Compton Imaging Telescope on the Compton Gamma-Ray Observatory

This experiment represented the first in-orbit imaging telescope for the 1-30 MeV energy band. As one of four experiments on NASA's Compton Gamma-Ray Observatory, it was launched by the Space Shuttle Atlantis on April 5, 1991. During its nine-year lifetime (which came to a premature end in June, 2000), it surveyed the entire sky and made deeper exposures of selected sky regions. Itprovided important new results on gamma-ray bursts, active galactic nuclei, pulsars, X-ray binaries and sources of nuclear line emission within the galaxy.

GRAPE is an instrument tailored to the specific task of performing direct polarization measurements of solar flares and gamma-ray bursts in the 50-300 keV energy range. This involves the Compton scatter polarimeter concept. To date we have carried out detailed design studies using Monte Carlo simulations and we have successfully demonstrated the basic approach using a laboratory prototype. A science model is currently being fabricated based on a design that utilizes an array of small plastic scintillators placed on the front surface of a 5" position senstive PMT. The goal is to provide a device suitable for studying gamma-ray bursts and for studying solar flares during the next solar maximum in 2010.

SONTRAC - Solar Neutron Tracking Experiment

The SONTRAC experiment is designed to measure the energy and incident direction of neutrons in the 20-300 MeV energy range. SONTRAC uses an imaging CCD camera to record the tracks of scattered protons in a scintillating fiber bundle. This concept has been successfully prototyped in the laboratory and we are presently seeking funds to build a complete device that would become available for use during the next solar maximum period. The SONTRAC concept has also attracted a great deal of attention outside the astrophysics community in such diverse fields as medical imaging and studies of high altitude radiation environments.

HESSI - High Energy Solar Spectroscopic Imager

Although originally developed as an imaging spectrometer for studying hard X-ray emission from the Sun, HESSI is also capable of making polarization measurements in the 20-200 keV energy range. UNH is responsible for developing the procedures and software necessary to perform polarization studies. The emphasis will be on the study of solar flares, but there may also be a possibility to perform such measurements on the Crab.

MEGA - Medium Energy Gamma-Ray Astronomy experiment

The development of this next-generation Compton imaging telescope is being led by colleagues at the Max Planck Instute for Extraterrestrial Physics (MPE) in Germany. The design was well-received in a recent German program for small satellite development. UNH is currently leading an American effort to garner NASA support to insure the success of this mission.

LXeGRIT - Liquid Xenon Gamma-ray Imaging Telescope

UNH researchers are working in collaboration with researchers at Columbia University to develop liquid xenon detectors for gamma-ray spectroscopy and imaging in astrophysics. As a result of several years of R&D at Columbia the liquid xenon technology is today a convincing new technology for gamma-ray instruments in space.

TIGRE - Tracking and Imaging Gamma-Ray Experiment

Initially designed to be flown as a balloon payload, TIGRE represents the next-generation of Compton imaging telescopes. It improves upon the success of COMPTEL by improving on the ability to define the kinematics of the Compton scatter event. It does not only by means of improvements in the spatial and energy resolution of both detector layers, but it also adds the important capability of tracking the scattered electron. The present design uses a stack of Silicon strip detectors as the upper detector layer and a series of CdZnTe strip detectors in the lower detector. Check out the UNH TIGRE publications list.

MARGIE - Minute of Arc Gamma-Ray Imaging Experiment

Initially intended to be flown as a balloon payload, MARGIE is designed to use the concept of coded-aperture imaging to achieve an angular resolution approaching 1 arc minute. This will require the development of detector technologies which can provide a photon interaction location with an acuracy of better than 1 mm. The MARGIE effort (currently led by UNH and Louisiana State University) is pursuing the development of two technologies to achieve that goal: CdZnTe strip detectors and CsI microfiber arrays with CCD readout. Check out the UNH MARGIE publications list.

CATSAT - The Cooperative Astrophysics and Technology Satellite

CATSAT is a small scientific satellite mission being developed jointly by the University of New Hampshire and the University of Leicester through the Universities Space Research Association (USRA)/NASA Student Explorer Demonstration Initiative (STEDI) program. It is designed to study the origin and nature Gamma Ray Bursters, one of the most mysterious astrophysical phenomenom. CATSAT is being largely designed, built and operated by student engineering teams with professional staff and teaching faculty as mentors. At the present time, there is no clear launch date for this mission.

FiberGLAST - A Scintillating Fiber Design for the Gamma-ray Large Area Space Telescope (GLAST)

UNH was involved, along with collaborators from Marshall Space Flight Center, the University of Alabama, Washington University and Louisiana State Univeresity, on an alternative design for NASA's next major gamma-ray mission, known as GLAST. This particular design, based on the user of scintillating fibers for tracking elecron-positron pairs, was not accepted for the design. Nonetheless, this approach is still considered viable and the FiberGLAST team hopes to further develop the basic technology so that it might be considered for a next-generation GLAST design. Check out the UNH FiberGLAST publications list.

MILAGRO - A Water-Cerenkov Telescope for TeV Gamma-Ray Astronomy

The MILAGRO experiment has recently been installed near Los Alamos, NM. It is designed to detect cosmic ray showers resulting from VHE photons (300 GeV - 1000 TeV) using a water-Cernekov technique. Unlike atmospheric Cerenkov detectors, it will provide a broad field-of-view instrument which can operate 24 hours a day. UNH has been involved in the use of Milagro data for studying ground level cosmic ray events triggered by solar flares. Check out the UNH Milagro publications list.

Ground-Level Neutron Monitors

UNH operates two ground-based neutron monitors for the purpose of studying atmospheric neutrons and, in particular, the solar cosmic rays that generate the atmospheric neutrons. One neutron monitor is located at the Mount Washington Observatory at an elevation of 6,000 feet above sea level. A second neutron monitor is located on the Durham campus, at sea level.

Guest Investigator Programs

These programs involve the analysis of public data from various Guest Investigator programs, involving orbiting experiments that were not developed at UNH. Among these are the BATSE, EGRET and OSSE experiments on the Compton Gamma-Ray Observatory (CGRO), the Roentgen Satellite (ROSAT), the Rossi X-Ray Timing Explorer (RXTE), and the International Gamma-ray Laboratory (INTEGRAL).

Ground-based studies have involved obervations made at the near-by Haystack Observatory, at the Very Large Array (VLA) and at the Australian Telescope Compact Array (ATCF). UNH is a member of the Northeast Radio Observatory Corporation (NEROC) that supports Haystack Observatory.

Last Updated: August 25, 2001