arXiv subjects

H. Graafsma

Publications and source records attributed to H. Graafsma.

8 recordsLinked to original sources

arXiv2025

Development & first Performance evaluation of multi-element monolithic HPGe detector for X-ray spectroscopy

The first operational prototype of a high-purity Germanium (HPGe) detector developed within the European LEAPS-INNOV project is presented in this work. This prototype features a monolithic, multi-element sensor optimized for high-resolution X-ray spectroscopy in the hard X-ray regime, capable of handling high count rates (20-250 kcps/mm2) across a broad energy range (5-100 keV). We discuss here a complete laboratory-based characterization of the detector's performance, as well as an on-beam evaluation at the BM05 beamline of the ESRF synchrotron facility, using monochromatic X-rays in the 20-50 keV energy range. We provide a detailed performance assessment that also includes a phenomenological defect-depth estimation model.

physics.ins-det↗

arXiv2025

Next Generation Multi-element monolithic Germanium detectors for Spectroscopy: First integration at ESRF facility

The XAFS-DET work package of the European LEAPS-INNOV project is developing a high-purity Germanium detectors for synchrotron applications requiring spectroscopic-grade response. The detectors integrate three key features: (1) newly designed monolithic Germanium sensors optimised to mitigate charge-sharing events, (2) an improved cooling and mechanical design structure supported by thermal simulations, and (3) complete electronic chain featuring a low-noise CMOS technology-based preamplifier. enabling high X-ray count rate capability over a broad energy range (5-100 keV). This paper discusses the first integration and characterization of one of the two multi-element Ge detectors at the European Synchrotron Radiation Facility (ESRF). The integration phase included validating high-throughput front-End electronics, integrating them with the Ge sensor, and operating them at liquid nitrogen temperature, in addition to the experimental characterization, which consists of electronics noise study and spectroscopic performance evaluation.

physics.ins-det↗

arXiv2025

Progress in the Development of Multi-Element Monolithic Germanium Detectors in LEAPS-INNOV Project: Insights from Detector Performance Simulation

This study presents a detailed simulation-based analysis of the detection limits of multi-element monolithic Germanium (Ge) detectors to cadmium traces in environmental soil samples. Using the capabilities of the Geant4 Monte Carlo toolkit in combination with the Solid State Detector Package, we evaluated the detection limit variation with the sample-to-detector distances and photon flux. These simulations were conducted to mimic realistic conditions, with a photon flux measured by the SAMBA beamline at the SOLEIL synchrotron facility. Our findings for the detection limit for trace amounts of pollutants in low concentrations like cadmium in the soil provide valuable insights for optimizing experimental setups in environmental monitoring and synchrotron-based applications, where precise detection of trace elements is critical.

physics.ins-det↗

arXiv2019

First demonstration of 3D optical readout of a TPC using a single photon sensitive Timepix3 based camera

The ARIADNE project is developing innovative optical readout technologies for two-phase liquid Argon time projection chambers (LArTPCs). Optical readout presents an exciting alternative to the current paradigm of charge readout. Optical readout is simple, scalable and cost effective. This paper presents first demonstration of 3D optical readout of TPC, using CF4 gas as a proof of principle. Both cosmic rays and an Americium-241 alpha source have been imaged in 100 mbar CF4. A single-photon sensitive camera was developed by combining a Timepix3 (TPX3) based camera with an image intensifier. When a pixel of TPX3 is hit, a packet containing all information about the hit is produced. This packet contains the x,y coordinates of the pixel, time of arrival (ToA) and time over threshold (ToT) information. The z position of the hit in the TPC is determined by combining drift velocity with ToA information. 3D event reconstruction is performed by combining the pixels x,y location with this calculated z position. Calorimetry is performed using time over threshold, a measure of the intensity of the hit.

physics.ins-det↗

arXiv2014

Intensity interferometry of single x-ray pulses from a synchrotron storage ring

We report on measurements of second-order intensity correlations at the high brilliance storage ring PETRA III using a prototype of the newly developed Adaptive Gain Integrating Pixel Detector (AGIPD). The detector recorded individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function was measured simultaneously at different spatial separations that allowed to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell-model.

physics.optics↗

arXiv2013

Performance tests of an AGIPD 0.4 assembly at the beamline P10 of PETRA III

The Adaptive Gain Integrating Pixel Detector (AGIPD) is a novel detector system, currently under development by a collaboration of DESY, the Paul Scherrer Institute in Switzerland, the University of Hamburg and the University of Bonn, and is primarily designed for use at the European XFEL. To verify key features of this detector, an AGIPD 0.4 test chip assembly was tested at the P10 beamline of the PETRA III synchrotron at DESY. The test chip successfully imaged both the direct synchrotron beam and single 7.05 keV photons at the same time, demonstrating the large dynamic range required for XFEL experiments. X-ray scattering measurements from a test sample agree with standard measurements and show the chip's capability of observing dynamics at the microsecond time scale.

physics.ins-det↗

arXiv2013

Challenges for the Adaptive Gain Integrating Pixel Detector (AGIPD) design due to the high intensity photon radiation environment at the European XFEL

The European X-ray Free Electron Laser (XFEL) is a new research facility currently under construction in Hamburg, Germany. With a pulse length of less than 100 fs and an extremely high luminosity of 27000 flashes per second the European XFEL will have a unique time structure that demands the development of new detectors tailored to the requirements imposed by the experiments while complying with the machine specific operation parameters. The Adaptive Gain Integrating Pixel Detector (AGIPD) is one response to the need for large 2D detectors, able to cope with the 4.5 MHz frame rate, as well as with the high dynamic range needed by XFEL experiments ranging from single photons to more than 10$^4$ 12 keV photons per pixel per pulse. In addition it has to withstand doses of up to 1 GGy over three years.

physics.ins-det↗

arXiv2012

R&D Paths of Pixel Detectors for Vertex Tracking and Radiation Imaging

This report reviews current trends in the R&D of semiconductor pixellated sensors for vertex tracking and radiation imaging. It identifies requirements of future HEP experiments at colliders, needed technological breakthroughs and highlights the relation to radiation detection and imaging applications in other fields of science.

physics.ins-det↗