Abstract
The Pohang-Accelerator-Laboratory X-ray free-electron laser (PAL-XFEL) provides intense ultra-short X-ray pulses via a self-amplified spontaneous emission (SASE) process. Since fluctuations are induced by the intrinsic characteristics of the SASE process, we designed and fabricated photo-diodes (PDs) to be used in quadrant beam position and pop-in monitoring systems for measuring intensity and position, and beam size, respectively. Six 500μm-thick high-resistivity silicon wafers were used for different fabrication processes to vary the thicknesses of bias electrode and anti-reflective coating layers optimized for the quantum efficiency (QE) at typical wavelengths of 266 and 400 nm used for pump–probe experiments at the PAL-XFEL. In this paper, we present the electrical characteristics, QE, signal-to-noise ratio, energy resolution of the fabricated PDs, and compared them with those of commercial PD.
Original language | English |
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Article number | 167598 |
Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
Volume | 1045 |
DOIs | |
State | Published - 1 Jan 2023 |
Keywords
- Energy resolution
- PIN photo-diode
- Pohang-Accelerator-Laboratory X-ray free-electron laser
- Quantum efficiency
- Signal-to-noise ratio