Avalanche photodiode based time-of-flight mass spectrometry.
This study reports on the performance of Avalanche Photodiodes (APDs) as a timing detector for ion Time-of-Flight (TOF) mass spectroscopy. We found that the fast signal carrier speed in a reach-through type APD enables an extremely short timescale response with a mass or energy independent <2 ns rise time for <200 keV ions (1-40 AMU) under proper bias voltage operations. When combined with a microchannel plate to detect start electron signals from an ultra-thin carbon foil, the APD comprises a novel TOF system that successfully operates with a <0.8 ns intrinsic timing resolution even using commercial off-the-shelf constant-fraction discriminators. By replacing conventional total-energy detectors in the TOF-Energy system, APDs offer significant power and mass savings or an anti-coincidence background rejection capability in future space instrumentation.
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
Keiichi
K
Ogasawara
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
Stefano A
SA
Livi
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
Mihir I
MI
Desai
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
Robert W
RW
Ebert
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
David J
DJ
McComas
Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238, USA.
Brandon C
BC
Walther