Thin Diamond Time-of-Flight Detectors

Rare isotope facilities serve a critical need for a rapidly expanding area of nuclear physics research. Existing rare isotope facilities already provide enough intensity that conventional detector systems have trouble with counting rates while future rare isotope facilities, like the Facility for Rare Isotope Beams (FRIB), will provide particle beams with unprecedented intensities and rates. Clearly, a challenge exists for particle detectors which will only worsen with time. The major advantages of using diamond detectors in this application are: (i) the use of simpler water-cooled systems and greater thermal stability; (ii) faster response with low noise, capacitance, and leakage current; and (iii) much longer lifetime because of its excellent radiation hardness. CVD diamond particle detectors present an advantage over the silicon detectors currently in use because of far superior thermal and electrical properties, and radiation hardness. During Phase I, we developed several techniques for improving the electronic properties of thin, polycrystalline diamond. These improvements were followed by the successful fabrication and testing of a time-of-flight detector for NSCL. During Phase II, we will build on this work by making a large area (200mm x 20mm) focal plane detector for NSCLs fragment separator. This detector will require advanced control of diamond thickness in addition to the improved electronic properties.Commercial Applications and Other Benefits: The proposed approach has the potential for a significant impact on particle accelerators used for nuclear physics experimentation around the world. The development of CVD diamond suitable for detector applications will also provide significant advances over other materials for neutron detection in oil exploration and nuclear power generation, and in beam monitoring and diagnosis in 3rd and 4th generation synchrotron facilities.