Abstract
As an alternative method for detecting low-energy ions, we describe the performance of a thin dead-layer avalanche photodiode (APD, Hamamatsu spl 6815), which provides high-resolution, proportional, and reliable efficiency with low mass and power even at room temperature. The pulse height distribution of the APD signal shows a significant peak for energies above 2.5 keV for protons and 3.4 keV for helium ions, with a noise level of ∼ 300 electrons (1.1 keV in silicon diode detectors). The response linearity is excellent for light ions, including protons and helium ions, with some non-linearity for heavier ions. The energy resolutions are 15% for 58 keV protons, 16% for 56 keV helium ions, 43% for 55 keV nitrogen ions and 46% for 55 keV argon ions. We also measured the thickness of a dead layer by analyzing the energy defect of 57 keV protons with different angles from the device surface, revealing a dead layer as thin as 340 Å. Considering the whole active-layer thickness of approximately 150 μ m, the maximum detectable energy was calculated to be ∼ 4 MeV / n for protons and helium ions.
Original language | English (US) |
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Pages (from-to) | 271-277 |
Number of pages | 7 |
Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
Volume | 614 |
Issue number | 2 |
DOIs | |
State | Published - Mar 1 2010 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Instrumentation
Keywords
- Avalanche photodiodes
- Particle detectors
- Solid-state detectors
- Space instrumentation