Detectors
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Abstract: At synchrotron facilities, many X-ray imaging and diffraction experiments require pixel detectors with minimal noise, high speed and reasonably small pixel size, all of which can be achieved with the Medipix ASIC family. So, ESRF, Diamond Light Source and DESY have developed detector systems based on Medipix. In this paper, we report on these developments, with an emphasis on the challenges involved building readout systems and the potential of the Medipix family ASICs in this field of research.
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Oct 2020
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B16-Test Beamline
Detectors
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K.
Metodiev
,
M.
Mironova
,
D.
Bortoletto
,
R.
Plackett
,
P.
Allport
,
I.
Asensi Tortajada
,
R.
Cardella
,
F.
Dachs
,
V.
Dao
,
M.
Dyndal
,
L.
Flores Sanz De Acedo
,
P.
Freeman
,
A.
Gabrielli
,
L.
Gonella
,
M.
Munker
,
H.
Pernegger
,
F.
Piro
,
P.
Riedler
,
A.
Sharma
,
E. J.
Schioppa
,
I.
Shipsey
,
W.
Snoeys
,
C.
Solans Sanchez
,
H.
Wennloef
,
D. P.
Weatherill
,
D.
Wood
,
S.
Worm
Diamond Proposal Number(s):
[2206]
Abstract: Detector prototypes are commonly characterised in testbeams, either using charged particles or X-rays. Charged particles are used to quantify detector performance in terms of absolute efficiency, while X-rays can provide additional information about the detector structure. This paper presents an alternative approach to calculating charged particle efficiencies, using the results of an X-ray testbeam of the mini-MALTA CMOS prototype at Diamond Light Source, and additional laboratory measurements. Results are presented for an unirradiated and an irradiated sample and compared to the results of charged particle testbeams at SPS and ELSA. The extrapolated efficiencies are in agreement with the measured values. Additionally, the extrapolated efficiency maps provide more insight about the location of the pixel inefficiencies, due to the better spatial resolution of the X-ray testbeam.
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Aug 2020
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B16-Test Beamline
Detectors
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Abstract: One of the major limitations of XAS experiment at synchrotron facilities is the performance of the detectors. In order to be able to measure more challenging samples and to cope with the very high photon flux of the current and future (diffraction limited) sources technological developments of detectors are necessary. This paper reports on the construction and characterization of a monolithic nineteen channel germanium detector demonstrator fitted with CMOS preamplifiers. The detector was characterized in the lab with radioactive sources and with the X-ray synchrotron beam. Characteristics such as energy resolution, linearity, counting rate capabilities, and stability of the detector were thoroughly evaluated. In addition, it was proved that by using an advanced pulse processor such as Xspress4 it was possible to improve the performance of the detector system by eliminating the cross talk among channels and by suppressing the charge shared events. This work could pave the way to enhanced germanium fluorescence detectors for high throughput X-ray spectroscopy.
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Jun 2020
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Detectors
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Abstract: This work presents the design and development of a CdTe sensor, Medipix3RXv2 readout ASICs photocounting detector of 55 pm pixel size arranged in an arc modular distribution for its use in X-ray Pair Distribution Function (PDF) applications at the Diamond Light Source (DLS) synchrotron. This contribution highlights the concept and technical solutions adopted for this new detector which include the development of a fibre optic link between the detector head and the readout FPGA cards. This solution enables a considerable reduction in the weight and size of the detector head.
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Apr 2020
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B16-Test Beamline
Detectors
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Leonardo
Abbene
,
Fabio
Principato
,
Gaetano
Gerardi
,
Antonino
Buttacavoli
,
Donato
Cascio
,
Manuele
Bettelli
,
Nicola
Sarzi Amade
,
Paul
Seller
,
Matthew C.
Veale
,
Oliver
Fox
,
Kawal
Sawhney
,
Silvia
Zanettini
,
Elio
Tomarchio
,
Andrea
Zappettini
Diamond Proposal Number(s):
[20545]
Abstract: In this work, the spectroscopic performances of new cadmium–zinc–telluride (CZT) pixel detectors recently developed at IMEM-CNR of Parma (Italy) are presented. Sub-millimetre arrays with pixel pitch less than 500 µm, based on boron oxide encapsulated vertical Bridgman grown CZT crystals, were fabricated. Excellent room-temperature performance characterizes the detectors even at high-bias-voltage operation (9000 V cm−1), with energy resolutions (FWHM) of 4% (0.9 keV), 1.7% (1 keV) and 1.3% (1.6 keV) at 22.1, 59.5 and 122.1 keV, respectively. Charge-sharing investigations were performed with both uncollimated and collimated synchrotron X-ray beams with particular attention to the mitigation of the charge losses at the inter-pixel gap region. High-rate measurements demonstrated the absence of high-flux radiation-induced polarization phenomena up to 2 × 106 photons mm−2 s−1. These activities are in the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging.
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Mar 2020
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Detectors
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I.
Sedgwick
,
F.
Krivan
,
I.
Shevyakov
,
M.
Zimmer
,
H.
Graafsma
,
G.
Cautero
,
D.
Giuressi
,
R.
Menk
,
G.
Pinaroli
,
L.
Stebel
,
A.
Greer
,
N.
Guerrini
,
U.
Pedersen
,
N.
Tartoni
,
S. Y.
Rah
,
H. J.
Hyun
,
K. S.
Kim
,
S. H.
Kim
,
B.
Boitrelle
,
F
Orsini
,
B.
Marsh
,
T.
Nicholls
,
A.
Marras
,
C. B.
Wunderer
,
J.
Correa
,
S.
Lange
,
M.
Kuhn
Abstract: High brilliance synchrotrons and Free Electron Lasers (FELs) require high performing detector systems to realise their full potential. High dynamic range, low noise and high frame rate are all of great importance. In this paper we describe the P2M CMOS sensor, designed for soft X-ray detection at such facilities. We refer to previous work on test devices demonstrating a noise of <16e-, a full well capacity of >5Me- and quantum efficiency of >80% at 400eV (and with good sensitivity even below this value). Initial test results on the first Front Side Illuminated (FSI) 2 Megapixel device are also presented, and an outline of future work is described.
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Nov 2019
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Detectors
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C. B.
Wunderer
,
J.
Correa
,
A.
Marras
,
S.
Aplin
,
B.
Boitrelle
,
P.
Goettlicher
,
F.
Krivan
,
M.
Kuhn
,
S.
Lange
,
M.
Niemann
,
F.
Okrent
,
I.
Shevyakov
,
M.
Zimmer
,
N.
Guerrini
,
B.
Marsh
,
I.
Sedgwick
,
G.
Cautero
,
D.
Giuressi
,
I.
Gregori
,
G.
Pinaroli
,
R.
Menk
,
L.
Stebel
,
A.
Greer
,
T.
Nicholls
,
U. K.
Pedersen
,
N.
Tartoni
,
H.
Hyun
,
K.
Kim
,
S.
Rah
,
H.
Graafsma
Abstract: The peak brilliance reached by today's Free-Electron Laser and Synchrotron light sources requires photon detectors matching their output intensity and other characteristics in order to fully realize the sources' potential. The Pixellated Energy Resolving CMOS Imager, Versatile And Large (Percival) is a dedicated soft X-ray imager (0.25–1 keV) developed for this purpose by a collaboration of DESY, Rutherford Appleton Laboratory/STFC, Elettra Sincrotrone Trieste, Diamond Light Source, and Pohang Accelerator Laboratory. Following several generations of prototypes, the Percival "P2M" 2-Megapixel imager—a 4.5×5 cm monolithic, stitched sensor with an uninterrupted imaging area of 4×4 cm2 (1408×1484 pixels of 27×27 μm—was produced and has demonstrated basic functionality with a first-light image using visible light. It is currently being brought to full operation in a front-illuminated configuration. The readout system being commissioned in parallel has been developed specifically for this imager which will produce—at full 300 Hz frame rate—data at 20 Gbit/s. A first wafer with eight Percival P2M chips has undergone backthinning to enable soft X-ray detection. It has been diced and chips are currently being wirebonded. We summarize here the P2M system, the project status, and show the P2M sensor's first response to visible light.
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Jan 2019
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Detectors
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Abstract: A single crystal CVD diamond detector with graphitic wire electrodes running beneath the diamond surface has been fabricated. This detector design is novel in that there is no surface metallisation present within the active region, and so the detector is a uniquely transmissive X-ray beam diagnostic instrument. This detector is designed to simultaneously measure the position, profile, and flux of an incident beam. It has applications in beam position and profile monitoring, and active beam feedback and stabilisation. To achieve this, a short-pulse laser, focused to micron-sizes using adaptive optics, can be used to graphitise arbitrary wire paths within bulk diamond. Presented in this paper is a transmissive X-ray pixel detector design with a 50-micrometre pixel pitch created using this technique. This pixel detector is produced by fabricating two separate arrays of parallel wires running under the surface of a diamond plate. The two arrays run perpendicular to each other, and parallel to the diamond surface. They are separated within the material by a depth of 100 microns. The parallel wires within each array are separated by 50-microns, and this is what determines the pixel pitch. Each of the crossing points between two wires from each array acts as a pixel. The signal from each pixel may be read out by measuring the signal current from each wire in one array whilst applying a bias voltage alternately to each wire in the other, perpendicular array. Alternatively, it is proposed to modulate the bias applied to each wire at a different frequency, from which the 2-dimensional beam profile may also be measured using a lock-in technique. This paper will provide an overview of the fabrication techniques for this first prototype detector, and provide a discussion of signal readout methods that will be used. An outline of the planned experimental tests is given.
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Jan 2019
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I10-Beamline for Advanced Dichroism
Detectors
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Alessandro
Marras
,
Cornelia
Wunderer
,
Jonathan
Correa
,
Benjamin
Boitrelle
,
Peter
Goettlicher
,
Manuela
Kuhn
,
Frantisek
Krivan
,
Sabine
Lange
,
Frank
Okrent
,
Igor
Shevyakov
,
Joshua
Supra
,
Maximilian
Tennert
,
Manfred
Zimmer
,
Niccola
Guerrini
,
Ben
Marsh
,
Iain
Sedgwick
,
Giuseppe
Cautero
,
Dario
Giuressi
,
Anastasya
Khromova
,
Ralf
Menk
,
Giovanni
Pinaroli
,
Luigi
Stebel
,
Alan
Greer
,
Tim
Nicholls
,
Ulrik
Pedersen
,
Nicola
Tartoni
,
Hyo Jung
Hyun
,
Kyung Sook
Kim
,
Seung Yu
Rah
,
Heinz
Graafsma
Abstract: In this paper, we are presenting the Percival detector, a monolithic CMOS Imager for detection of soft x-rays in Synchrotron Rings and Free Electron Lasers. The imager consists in a 2D array of many (2M) small (27um pitch) pixels, without dead or blind zones in the imaging area. The imager achieves low noise and high dynamic range by means of an adaptive-gain in-pixel circuitry, that has been validated on prototypes. The imager features on-chip Analogue-to-Digital conversion to 12+1 bits, and has a readout speed which is compatible with most of Free Electron Laser Facilities. For direct detection of low-energy x-rays, the imager is back-illuminated and post-processed to achieve 100% fill factor.
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Jan 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
Detectors
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Abstract: Using a range of zero-biased InGaAs Schottky diode detectors, terahertz coherent synchrotron radiation emitted by individual electron bunches has been detected. The source was the UK's Diamond Light Source synchrotron operating in low-alpha THz mode. Detected signals have a FWHM of <50 picoseconds, and a spectral bandwidth of 0.2 – 3 THz. Due to the sensitivity, high linearity and fast recovery of the detectors, we were able to record the THz emission from a series of bunches over several synchrotron round trips.
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Oct 2018
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