MRI: Development of ASIC's Suite for Analog Processing of Signals from Large Arrays of Silicon-Strip Detectors and PSD-Capable Scintillators

Southern Illinois University At Edwardsville, Edwardsville IL

Investigators

Abstract

This award supports the ASIC (Application Specific Integrated Circuit) chip fabrication that will expand the capabilities of two low energy nuclear physics experiments aimed at understanding the complex structure of exotic nuclei. The first experiment will take place at the NSCL (National Superconducting Cyclotron Laboratory) and will compare oxygen and lithium isotopes, which have mirror-like structure and can lead to the nucleosynthesis of heavier isotopes such as argon and chlorine. The second experiment will take place at Florida State University and investigate reactions that play a major role in understanding the products of explosive astrophysical events such as novae and x-ray bursts. The undergraduate and graduate students involved in the project will receive excellent preparation for professional careers in forefront physics and engineering and in the growing overlap areas. More specifically, this award supports the development, design and fabrication of ASIC chips that extend the scientific reach of (at least) two programs. One of these programs, led by the Washington University reactions group, uses the invariant mass technique to study the continuum structure of proton-rich nuclei. This program will use the upgraded HINP (Heavy Ion Nuclear Physics) chip at NSCL to search for the ground state in O-11, which is the mirror of Li-11, the prototype exotic nucleus (huge n/p asymmetry). These measurements, and others planned by this and other groups, require electronics with both large dynamic range and excellent resolution, features included in the new ASIC design. A second empowered experimental program will use (d,n) reactions as a surrogate for astrophysically relevant (p,gamma) reactions. Such experiments have to contend with physical neutron cross talk (in the neutron detectors themselves) and gamma background. The technology of the PSD (Pulse Shape Discrimination) chip enables large arrays of neutron-sensitive detectors that can reduce these problems. These experiments will be led by a Florida State University group, initially at their local facility and later at both Argonne National Laboratory and the future Facility for Rare Isotope Beams (FRIB).