Support

ARIZONA STATE UNIVERSITY
CENTER FOR BIOLOGICAL PHYSICS

*SPECIAL SEMINAR*

Monday, November 17, 2014

2:30 PM

487 Goldwater Center

Cornelia “Trixi” Wunderer

DESY Photon Science Detector Group

Host:  John Spence

Area Detectors for XFELs - Challenges and Developments

Abstract

With the increased brilliance of state-of-the-art Synchrotron radiation sources and the advent of Free Electron Lasers enabling revolutionary science with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon counting capability with low probability of false positives, and (multi)-megapixels.

At DESY, one ongoing development project - in a collaboration with RAL/STFC, Elettra, Diamond, and Pohang Accelerator Laboratory - is the CMOS-based soft X-ray imager Percival. PERCIVAL is a monolithic active pixel sensor (MAPS) that will be back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to its preliminary specifications, the roughly 10 x 10cm2, 3.5k x 3.7k monolithic sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within its 27 micron pixels to measure 1 to ~ 100,000 (500 eV) simultaneously-arriving photons.

DESY is also leading the development of AGIPD, a high speed detector based on hybrid pixel technology intended for use at the European XFEL. It allows single pulse imaging at 4.5 MHz frame rate into a 352-frame buffer, with a dynamic range allowing single photon detection and detection of more than 10,000 12.4 keV photons in the same image.

The talk will cover the detector challenges posed by XFEL experiments, and describe AGIPD and PERCIVAL - as well as touch on some other currently ongoing X-ray area detector developments focused on XFEL applications.