Speaker
Description
Single-crystal diamond is a wide-bandgap semiconductor with attractive material properties for fast timing detectors. The electron and hole saturation velocities exceed those of silicon, and thanks to the wide bandgap, the leakage current after irradiation is negligible and diamond detectors can even be operated at elevated temperatures (>300 °C). Recently, the exceptional breakdown field and thermal conductivity of diamond have resulted in significant investments by the power electronics industry, and substrate size and quality are improving rapidly.
We present ongoing work at SCIPP on diamond detectors for timing and high-bandwidth detection applications. Thin (30 µm) diamond detectors have been used for ion time-of-flight and X-ray detection in laser-plasma environments during a campaign at the Titan short-pulse laser (Jupiter Laser Facility, LLNL). Aiming at fusion diagnostics applications, we have developed high-bandwidth readout electronics and a novel electro-optic readout scheme, enabling long-distance signal transmission with rise times below 100 ps and immunity to EMP.
For single-MIP timing, the low charge yield of thin diamond sensors (~36 e-h pairs/µm) strongly motivates detectors with internal amplification. We present simulations of the timing performance of diamond detectors with gain, comparing them to 4H-SiC, GaN and silicon LGADs, and discuss the challenges and possible paths towards diamond-based LGADs.