A High-Speed One-Dimensional Detector for Time-Resolved Small-Angle X-Ray Scattering: Design and Characterization
| Autor: | Patrick M. De Lurgio, Guy Jennings, A. Kreps, Michael Molitsky, Istvan Naday, John Weizeorick, Jan P. Hessler, Gary Drake |
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| Rok vydání: | 2010 |
| Předmět: |
Physics
Transimpedance amplifier Nuclear and High Energy Physics Physics::Instrumentation and Detectors Scattering business.industry Detector X-ray detector Advanced Photon Source Particle detector Optics Nuclear Energy and Engineering Shutter Electrical and Electronic Engineering Small-angle scattering business |
| Zdroj: | IEEE Transactions on Nuclear Science. 57:1706-1715 |
| ISSN: | 1558-1578 0018-9499 |
| Popis: | A high-speed one-dimensional detector for time-resolved small-angle x-ray scattering has been designed and built for experiments at the Advanced Photon Source of Argonne National Laboratory. This detector is made from a 500-μm thick by 150-mm diameter ultra-high-purity n-type silicon wafer. The electrodes, which are a series of concentric rings that are deposited in the wafer, integrate the scattered x-rays over the azimuthal angle and, thereby, produce a one-dimensional detector. This design yields 128 rings, which allows parallel processing of the signal from each ring. The readout electronics consist of transimpedance front-end amplifiers, one for each ring, followed by active pulse-shaping filters. The amplifier signals are digitized using 12-bit analog-to-digital converters, one per ring, which operate at 20 MHz. The frame rate of the system is 271 kHz. Up to 220 - 1 scattering profiles may be stored on a random access memory chip and transferred to a data file at a rate of 16 × 103 profiles/sec. For X-ray energies between 3.5 and 13.2 keV the efficiency exceeds 80%. The resolving time of the electronics is 300 ns, which is sufficient to isolate electronically a single pulse of scattered x-rays when the synchrotron is operated in a hybrid or asymmetric fill pattern. Therefore, laser-pump/x-ray-probe experiments can be performed without a mechanical shutter. Examples of time-resolved speckle and the kinetics of the formation of sodium chloride particles are presented. This detector is capable of acquiring small-angle x-ray scattering profiles over multiple time scales, which are needed to characterize many chemical, physical, and biological processes. In addition, this detector may be tested and calibrated before experimental runs, without access to an intense beam of x-rays, with alpha particles from a radioactive source such as 241Am. |
| Databáze: | OpenAIRE |
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