Characterisation of Ge micro-strip sensors with a micro-focused X-ray beam

DOI: 10.1016/j.nima.2020.164932

Authors: M. Borri (Science and Technology Facilities Council (STFC)) , C. Cohen (ESRF) , O. Fox (Diamond Light Source) , J. Groves (STFC Daresbury Laboratory) , W. Helsby (STFC Daresbury Laboratory) , O. Mathon (ESRF) , L. Mcnicholl (STFC Daresbury Laboratory) , S. Pascarelli (ESRF) , K. Sawhney (Diamond Light Source) , R. Torchio (ESRF) , M. Zuvic (Mirion Technologies (Canberra))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nuclear Instruments And Methods In Physics Research Section A: Accelerators, Spectrometers, Detectors And Associated Equipment

State: Published (Approved)
Published: December 2020
Diamond Proposal Number(s): 24637

Abstract: Germanium micro-strip sensors were selected as the sensor technology to take data in energy dispersive X-ray spectroscopy experiments at the Extremely Brilliant Source (EBS) in Grenoble (FR). It is important for this experimental technique to use sensors with a large uniform area and a fine pitch. The former determines the range of energy detectable with a single sensor. The latter improves spectral resolution. A high stopping power is also important to perform studies with hard X-rays. The device under test in this measurement was a germanium micro-strip sensor made of 1024 strips with pitch. The bulk was 1.5 mm thick. The sensor was assembled into a prototype cryostat part of the XH detector system. The device was tested at the B16 beamline at the Diamond Light Source (DLS) in Didcot (UK). The objective of the test-beam was to characterise charge-sharing between strips. In fact, this effect limits the spectral resolution of the device. To carry out this test, the sensor was scanned over a subset of strips with micro-focused X-rays under different settings. These were beam energy and intensity, sensor temperature and bias voltage. Results are presented in this paper. It was measured that the full width half maximum of the charge-sharing profile across different strips was for settings which were indicative of the experimental conditions at the EBS. This was a signal current per unit area on the sensor of 10−8 A/ , a bias voltage of -180 V and a temperature of -159 C.

Journal Keywords: Germanium; Micro-strip sensors; Cryogenic detector systems; Hard X-rays; Energy dispersive spectroscopy

Subject Areas: Physics


Instruments: B16-Test Beamline

Other Facilities: Extremely Brilliant Source (EBS), ESRF

Documents:
1-s2.0-S0168900220313292-main.pdf