Louisiana State University Physics & Astronomy

Space Science/Particle Astrophysics

The Space Science/Particle Astrophysics group works extensively with old and new experiments that fly on satellites. Our group is forward looking with design and development for future missions, including ACCESS and CASTER. The ACCESS experiment is to fly on the International Space Station in about 2007 to study the composition, spectra, and interactions of cosmic ray protons and nuclei at energies up to the 'knee' in the cosmic ray spectrum at 10¹⁵ eV. The CASTER program is proposed as part of the Beyond Einstein initiative of NASA as a Black Hole Finder. The goal is to make a complete survey of the sky in hard x-rays and gamma-rays (30-600 keV) with remarkably high angular resolution. Data from both the BATSE and COMPTEL experiments on the Compton Gamma Ray Observatory are being analyzed for multi-wavelength studies of active galaxies, micro-quasars, and black hole binaries.

The group is active with balloon experiments, with flights out of Texas Canada and the Antarctic. Past examples of LSU balloon programs are JACEE and SMILI. The MARGIE experiment, to perform high angular resolution (~4 arc-minutes!) studies of cosmic x-rays and gamma rays in the energy range 20-600 keV, has been selected as a mission concept proposal for NASA's Ultra-Long Duration (100 day) Balloon program. We are presently involved in the detector development and instrument design. The detectors have applications to medical imaging and biological research, nondestructive testing, remote surveillance, and other commercial uses, as well as astrophysics. The ATIC balloon-borne detector has already flown twice in Antarctica and will soon fly there again. It is designed to measure cosmic rays in the energy range about 10¹¹-10¹⁴ eV with a Bismuth Germanate calorimeter, scintillator hodoscopes and a pixelated Silicon-matrix detector. ATIC also serves as a possible prototype for ACCESS, which is planned to be a large TRD/Calorimeter experiment for space, either a free-flyer or an attached space station payload.
The LaACES program is giving undergraduate students a true hands-on experience with project management, life-cycle, experiment design, construction, testing, data collection, analysis and interpretation. During LaACES, students design, build, test, fly and analyze the data returned from small balloon payloads (typical dimensions 10 cm x 10 cm x 10 cm, typical weight ~500 grams) carried up to ~100,000 feet by a helium-filled latex sounding balloon, launched from the National Scientific Balloon Facility in Palestine, Texas.
The Pierre Auger Project will measure the highest energy (>10¹⁹ eV) cosmic rays. No known mechanism can fully account for the acceleration of cosmic rays to such high energies. Their extreme energy ensures that they suffer little deflection when passing through relatively weak Galactic or intergalactic magnetic fields. Cosmic rays also interact with the cosmic background radiation, so any observed at earth must have originated within about 100 Mpc. The first observatory, covering 3000 km² in western Argentina is half complete; construction of a similar facility in the US will start in 2007.

Updated: Thu, 12-Jul-2007 3:42 PM