The high dynamic range pixel array detector (HDR-PAD): Concept and design

Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 1088-keV photons pixel−1s−1, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 1010 photons µm−2s−1within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while `still' images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described.

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In situtwo-dimensional imaging quick-scanning XAFS with pixel array detector

Journal of Synchrotron Radiation ◽

10.1107/s0909049511031232 ◽

2011 ◽

Vol 18 (6) ◽

pp. 919-922 ◽

Cited By ~ 18

Author(s):

Hajime Tanida ◽

Hisao Yamashige ◽

Yuki Orikasa ◽

Masatsugu Oishi ◽

Yu Takanashi ◽

...

Keyword(s):

Dynamic Range ◽

Signal To Noise Ratio ◽

Low Noise ◽

Array Detector ◽

Large Area ◽

Scanning Method ◽

Two Dimensional Image ◽

Pixel Array ◽

Pixel Array Detector ◽

Good Signal

Quick-scanning X-ray absorption fine structure (XAFS) measurements were performed in transmission mode using a PILATUS 100K pixel array detector (PAD). The method can display a two-dimensional image for a large area of the order of a centimetre with a spatial resolution of 0.2 mm at each energy point in the XAFS spectrum. The time resolution of the quick-scanning method ranged from 10 s to 1 min per spectrum depending on the energy range. The PAD has a wide dynamic range and low noise, so the obtained spectra have a good signal-to-noise ratio.

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High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927615015664 ◽

2016 ◽

Vol 22 (1) ◽

pp. 237-249 ◽

Cited By ~ 163

Author(s):

Mark W. Tate ◽

Prafull Purohit ◽

Darol Chamberlain ◽

Kayla X. Nguyen ◽

Robert Hovden ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electron Microscope ◽

Scanning Transmission Electron Microscopy ◽

Dynamic Range ◽

Array Detector ◽

Transmission Electron ◽

Pixel Array ◽

Scanning Transmission ◽

Pixel Array Detector

AbstractWe describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80–200 keV electron beams.

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Sub-microsecond-resolved multi-speckle X-ray photon correlation spectroscopy with a pixel array detector

Journal of Synchrotron Radiation ◽

10.1107/s1600577518009074 ◽

2018 ◽

Vol 25 (5) ◽

pp. 1408-1416 ◽

Cited By ~ 12

Author(s):

Qingteng Zhang ◽

Eric M. Dufresne ◽

Suresh Narayanan ◽

Piotr Maj ◽

Anna Koziol ◽

...

Keyword(s):

Dynamic Range ◽

Photon Correlation Spectroscopy ◽

Correlation Spectroscopy ◽

Acquisition Time ◽

Array Detector ◽

Photon Correlation ◽

X Ray ◽

Burst Mode ◽

Pixel Array ◽

Pixel Array Detector

Small-angle X-ray photon correlation spectroscopy (XPCS) measurements spanning delay times from 826 ns to 52.8 s were performed using a photon-counting pixel array detector with a dynamic range of 0–3 (2 bits). Fine resolution and a wide dynamic range of time scales was achieved by combining two modes of operation of the detector: (i) continuous mode, where data acquisition and data readout are performed in parallel with a frame acquisition time of 19.36 µs, and (ii) burst mode, where 12 frames are acquired with frame integration times of either 2.56 µs frame−1or 826 ns frame−1followed by 3.49 ms or 1.16 ms, respectively, for readout. The applicability of the detector for performing multi-speckle XPCS was demonstrated by measuring the Brownian dynamics of 10 nm-radius gold and 57 nm-radius silica colloids in water at room temperature. In addition, the capability of the detector to faithfully record one- and two-photon counts was examined by comparing the statistical distribution of photon counts with expected probabilities from the negative binomial distribution. It was found that in burst mode the ratio of 2 s to 1 s is markedly smaller than predicted and that this is attributable to pixel-response dead-time.

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