Synchrotron characterization of high-Z, current-mode x-ray detectors

Area of Science:

• Materials Science
• Physics
• Engineering

Background:

• Fast x-ray detectors with nanosecond impulse response are essential for pulsed power and fusion applications.
• Semiconductor detectors offer a flexible platform for developing sensitive and rapid x-ray detection.
• A common challenge is balancing detector sensitivity with speed, often addressed by optimizing absorber materials.

Purpose of the Study:

• To evaluate the x-ray absorption efficiency and temporal impulse response of semiconductor x-ray detectors.
• To investigate the performance of silicon (Si), gallium arsenide (GaAs), and cadmium telluride (CdTe) detectors.
• To explore the impact of higher atomic number absorbers on detector speed and sensitivity.

Main Methods:

• X-ray pulse characterization using a high-brilliance synchrotron source at the Advanced Photon Source.
• Measurement of x-ray absorption efficiency across different semiconductor materials.
• Analysis of the temporal impulse response to determine detector speed.

Main Results:

• Demonstrated that higher atomic number materials can improve hard x-ray absorption.
• Confirmed that high carrier velocity in absorbers can maintain fast charge collection times.
• Presented comparative data on the performance of Si, GaAs, and CdTe detectors.

Conclusions:

• Semiconductor detectors, particularly those with higher atomic number absorbers, show promise for achieving both high sensitivity and fast response times.
• The findings support the development of advanced x-ray detectors for demanding scientific applications.
• Material selection is critical for optimizing detector performance in pulsed power and fusion research.