This paper presents the test results of a mock-up detector-module modelling the configuration of a High Purity Germanium (HPGe) planar detector coupled to room temperature electronics. The mock-up detector-module was designed, fabricated and tested inside a liquid nitrogen (LN2) cryostat.The mock-up module and the related test results provide a reference layout and dataset that can be used to de-risk the adaptation of the design to project specific needs.The tests performed on the mock-up detector-module include measurements of the thermal flow across the components, assessment of the effect of the infrared load on the internal mechanics, calculation of parasitic thermal losses via quantification of the boil-off rate of LN2.

This project addresses the challenge related to the operation of High Purity Germanium (HPGe) sensors in hybrid pixel detectors for the detection of hard X-rays. Usually, the operation of cryogenic sensors like HPGe sensors in hybrid pixel detectors is related to the development of cryogenic Application Specific Integrated Circuits (ASICs). This is somehow still a niche technical area restricting the range of applications and resulting in high development costs. Instead, it is proposed an alternative concept aimed at popularising the use of HPGe sensors with any available pixel ASIC which is designed for room temperature operation. This approach is based on the technical capability of managing an extreme temperature gradient between the ASIC and the sensor, while maintaining outstanding electrical performance and mechanical stability. We called “micro thermal-divider” the combination of the micro-fabrication technologies and the micro-electronics interconnection techniques enabling the control of extreme temperature gradients in a hybrid pixel detector. This contribution introduces the rationale and the requirements for the micro thermal-divider.

This paper presents a new X-ray irradiation facility that was opened at the UKRI-STFC Daresbury Laboratory, UK.The facility supports the core-research at Daresbury Laboratory in two key areas. The first one is the development of High Purity Germanium systems for the detection of hard X-rays at accelerator based light sources. The second one is the development of radiation-hard electronics for collider experiments, starting with the R&D on CMOS sensors for the Electron Ion Collider. The facility also aims to support the wider community of innovators on the Daresbury Campus, like the UK, North-West, Space-Tech network of entrepreneurs. This contribution will describe the key features of the facility and the related commissioning results.

This paper describes technical details and new scientific opportunities offered by the new High Power Laser Facility at the ESRF, opened to users since 2022. This facility enables laser-induced dynamic compression experiments probed by ultra-fast X-ray Absorption Spectroscopy at beamline ID24-ED. This capability allows to reach and probe more extreme pressure and temperature states and higher strain rates with respect to static compression, addressing open questions in fundamental, planetary and material science.

Spectroscopic X-ray imaging techniques including Compton X-ray Imaging, X-ray Fluorescence Imaging and Hyperspectral X-ray Tomography require energy-resolving detectors capable of operating at high incident X-ray fluxes to make time resolved measurements. HEXITECMHz, operates at a continuous 1 MHz frame rate and can make fully spectroscopic measurements at >10(6) ph s(-1) mm(-2). This is enabled by an integrating Front End, in-pixel digitisation and high-speed serialisers. A 300 mu m thick p-type Si HEXITECMHz detector was characterised on the B16 Test Beamline at the Diamond Light Source and are the first measurements taken at a 1 MHz frame rate. At 10 keV and 15 keV) the device displayed average FWHM of 656 eV and 682 eV respectively, with minimal changes in spectroscopic performance over similar to 8 h. Analysis of charge-sharing events show low charge loss and a linear energy-signal response. Higher-flux measurements illustrated the capability of the ASIC to operate as a photon-counting device.

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 50 mu m 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 similar to 90 mu m for settings which were indicative of the experimental conditions at the EBS. This was a signal current per unit area on the sensor of similar to 1.66x10(-8) A/mu m(2), a bias voltage of -180 V and a temperature of -159 degrees C.

Energy dispersive X-ray spectrometers provide a method for the fast data acquisition of X-ray absorption spectra. The intensity of the spectral components of a polychromatic beam is detected simultaneously after being dispersed in space, and being transmitted by an experimental sample. The cryogenic detector system called XH deploys a germanium micro-strip sensor to perform such measurements. Here, the geometrical position of each strip is correlated to a specific spectral component of the dispersed beam. The prototyping experience reported in this work is related to the upgrade of the cryostat unit of the XH detector system. This upgrade was carried out in collaboration with beam-line ID24 at the European Synchrotron Radiation Facility (ESRF). Two 90 mm wafers of p-type high purity germanium were manufactured. Wafers contained test structures and micro-strip sensors made of 1024 strips with 50 mu m pitch. Electrical and in-beam tests were performed to verify the performance of this technology. The measurements included capacitance-voltage characteristics; stress-tests like temperature cycling testing and burn-in tests; leakage current as a function of sensor temperature; charge-collection as a function of time; a test-run of a pump and probe experiment. Results are reported below showing that this sensor technology survived the extensive thermal and electrical stress-tests, and that it was able to measure the physical variations created by a laser shock on a sample of Fe-10%wtNi.

We present in this paper recent advances in the high pressure domain provided by the introduction of time-resolved energy-dispersive XAS (EDXAS) techniques at synchrotrons. We highlight technical aspects and describe two modes of acquisition: the movie' mode, where the time resolution is given by the detector acquisition speed and the pump-and-probe' mode, where the time resolution is given by the delay between the pump and the probe. These two modes define a frontier in the time resolution, respectively above and below the approximate to 10s regime. In the former, examples of applications are chemical stability and reactions at high pressure and high temperature or probing the warm dense matter regime using rapid current ramps. In the latter, an example is given on studies of dynamically compressed matter, by coupling single-bunch EDXAS at high-brilliance synchrotron to a nanosecond high-power laser.

A new beamline (MPW6.2) has been designed and built for the study of materials during processing where three synchrotron techniques, SAXS, WAXS and XAS, are available simultaneously. It has been demonstrated that Rietveld refinable data can be collected from silicon SRM 640b over a 60 degrees range in a time scale of 1 s. The data have been refined to a chi(2) of 2.4, the peaks fitting best to a Pearson VII function or with fundamental parameters. The peak halfwidths have been found to be approximately constant at 0.06 degrees over a 120 degrees angular range indicating that the instrumental resolution function has matched its design specification. A quantitative comparison of data sets collected on the same isotactic polypropylene system on MPW6.2 and DUBBLE at the ESRF shows a 17% improvement in angular resolution and a 1.8 improvement in peak-to-background ratio with the RAPID2 system; the ESRF data vary more smoothly across detector channels. The time-dependent wide-angle XRD was tested by comparing a hydration reaction of gypsum-bassanite-anhydrite with energy-dispersive data collected on the same system on the same time scale. Three sample data sets from the reaction were selected for analysis and gave an average chi(2) of 3.8. The Rietveld-refined lattice parameters are a good match with published values and the corresponding errors show a mean value of 3.3 x 10(-4). The data have also been analysed by the Pawley decomposition phase-modelling technique demonstrating the ability of the station to quickly and accurately identify new phases. The combined SAXS/WAXS capability of the station was tested with the crystallization and spinodal decomposition of a very dilute polymer system. Our measurements show that the crystallization of a high-density co-polymer (E76B38) as low as 0.5% by weight can be observed in solution in hexane. The WAXS and SAXS data sets were collected on the same time scale. The SAXS detector was calibrated using a collagen sample that gave 30 orders of diffraction in 1 s of data collection. The combined XRD and XAS measurement capability of the station was tested by observing the collapse and re-crystallization of zinc-exchanged zeolite A (zeolite Zn/Na-A). Previous studies of this material on station 9.3 at the SRS were compared with those from the new station. A time improvement of 38 was observed with better quality counting statistics. The improved angular resolution from the WAXS detector enabled new peaks to be identified.

A novel area detector has been designed for material science SR studies, capable of simultaneously collecting the diffraction data in two angular regimes. The detector for collecting wide-angle X-ray scattering (WAXS) data consists of four taper-coupled CCDs arranged as a 2×2 mosaic with a central aperture about 40mm in diameter, so permitting the inclusion of a distant on-axis CCD detector for small-angle X-ray scattering (SAXS). The distance of the SAXS detector from the sample can be varied over the range 0.27m to about 2m. The overall aperture of WAXS detector is approximately 200×200mm2 allowing the measurement of the diffraction patterns from 5° to 45° with an average angular resolution of 0.05°. The parallax error for large angles is substantially reduced as the individual WAXS CCDs are tilted towards the specimen location. Both WAXS and SAXS diffraction data are simultaneously collected at 30MB/s data rate, which is equivalent to 6 complete frames per second. Each pixel value is digitised using low- and high gain Analogue-to-Digital Converters (ADCs) which effectively increase the detector's overall dynamic range. The detector will be used in the study of a whole range of time-dependent phenomena, most importantly reaction kinetics, materials processing and real-time deformation studies. This paper discusses the unusual geometry of the system, how it relates to design optimisation and the techniques for recovering combined SAXS/WAXS patterns.

The application of the Multi-Wire Proportional Counter (MWPC) as a potential detector for protein crystallography and other wide-angle diffraction experiments is presented. Electrostatic problems found with our large area MWPC when operated at high pressure are discussed. We suggest that a solution to these problems is to use a glass micro-strip detector in place of the wire frames. The characteristics of a high-pressure Micro-Strip Gas Chamber (MSGC) tested in the laboratory are presented.

Multi Wire Proportional Counters (MWPCs) possess all the required features for recording X-ray diffraction patterns: large area, high detective quantum efficiency (DQE), low dead time and simultaneous spatial and spectral information. However, their suitability as wide-angle diffraction is compromised by an effect known as parallax broadening. This phenomenon is due to the low density of the gas in the detector, where photons incident at large angles following the same ray may interact at different points along it and therefore appear as different coordinates in the image. One way to reduce this effect is by increasing the density of the absorbing medium in order to ensure the photons interact in a thinner gas layer, this can be achieved if the pressure of the gas in the detector is increased. We present here a high-pressure (5 bar) detector which has the potential to bring the desirable features of a photon counting system to wide-angle diffraction experiments. The preliminary results are also presented.

Multi-wire proportional counters with delay line readout are the standard detectors in use on small angle X-ray diffraction beam lines at the Synchrotron Radiation Source (SRS). Their sensitivity and speed of readout would make them a desirable detector for large angle diffraction stations if it were not for the image distortion caused by 'parallax smearing'. This aberration occurs because of the large range of path lengths prior to interaction in the gas for the photon energies of interest similar to 10 keV (1.2 Angstrom). A potential solution to this problem is the secondary electron emission (SEE) detector in which the secondary electrons from photoelectric interactions in a thin layer of suitable material are detected, Detectors based on this principle have been successfully built, and demonstrated at the ESRF. However, their detection efficiency is poor due to the low escape probability of the secondary electrons from the photoconverter. The SRS detector group in collaboration with the University of Leicester Physics and Astronomy department, have attempted to use a CsI coated microchannel plate as the photo-converter. It was initially thought that a carefully designed MCP might improve upon the efficiency of a single layer of material. When run at very low gain the MCP has been shown to be capable of operating in a low pressure MWPC with a standard readout system. An MCP designed for soft X-ray detection was used in this preliminary study and the detection efficiency was found to be poor. Alternative MCP designs are discussed.

Multiwire proportional counters (MWPCs) have been used regularly on the Synchrotron Radiation Source (SRS) at Daresbury. They are photon counting, can cover large areas, and have fast readout times which makes them attractive to study dynamic processes such as muscle contraction. However, their operation at high rates has been a major limitation, due to two factors, space charge in the detector reducing the local count rate capability, and slow readout electronics which reduces the global count rate.The Daresbury biological X-ray detector group have developed a new type of detector called the wire microgap which significantly improves the local count rate capability of the detector. Coupled to this is a complex 1D electronic readout system which uses an amplifier and discriminator per wire and can handle charge spreading across two wires. The result is a 1D detector system 200 x 15 mm active area which can accept a global count rate of 200 MHz.This paper describes the design and performance of the detector and readout system and presents some results illustrating the fast framing capability of the detector which demonstrate a single shot timing sequence with a resolution of 50 mu s. Also presented are recent beamline results.

We present the first results from two highly parallel detector systems designed for fast time resolved x-ray diffraction experiments. The readout systems have been designed to give throughputs well in excess of 107 events per second. The detector systems have been designed to allow high flux diffraction patterns to be collected with very much reduced rate effects when compared with previous designs. This has been achieved using wire microgap proportional counters coupled to multi-channel data acquisition systems. The efficiency and low noise of the detector coupled to the speed of the readout has produced a detector system capable of more fully exploiting the time resolved diffraction stations on the UK Synchrotron Radiation Source at the Daresbury Laboratory. Modifications to the design will be presented which will allow the system to cope with even higher count rates in the future.

The multiwire proportional counter (MWPC) is well established device for capturing x-ray images at synchrotron sources such as at the synchrotron radiation source (SRS) at Daresbury. The latest generation of synchrotrons can deliver much more intense x-ray fluxes than the SRS which itself produces xray fluxes well beyond the capabilities of current photon counting detectors, There is an imminent demand for 2-D photon counting detectors which can cope with rates >10(5) photons/mm(2)/sec locally and readout systems with an unbuffered throughput of >10(7) events per second. This must be achieved with a high dynamic range and a good efficiency. The detector development group at the SRS have developed the wire microgap detector to address these problems. A new readout system has been designed using a highly parallel approach. Each detector channel in the detector is separately instrumented, and the data is accumulated using fast, state-of-the-art electronics systems. A prototype of the system has been constructed and tested with the 2 dimensional wire microgap detector. We report the results of the use of a wire microgap linear detector on the SRS and the first results from the 2D wire microgap detector system.

Multiwire proportional counters (MWPCs) currently in use for synchrotron radiation diffraction offer unrivalled dynamic range and detection efficiency. Unfortunately they have, until recently, been somewhat limited in count rate performance and suffer from parallax problems with incoming photons at high angles of incidence. We report on the progress of a fast 2-D proportional counter detector for use on the beamlines at the Synchrotron Radiation source at Daresbury. It utilises a highly parallel data acquisition system in order to achieve photon counting rates in excess of 106 counts per second. This is coupled to a pressurised proportional counter to reduce the parallax errors. The detector will have a 200 mm by 200 mm active area and the system will yield a real spatial resolution of ∼ 200 μm (FWHM). A review of the system components is made, and a technique for further improving the performance is described.