Open AccessUltra‐thin optical grade scCVD diamond as X‐ray beam position monitor
Author(s) -
Desjardins Kewin,
Pomorski Michal,
Morse John
Publication year - 2014
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577514016191
Subject(s) - diamond , chemical vapor deposition , materials science , synchrotron , optics , beam (structure) , etching (microfabrication) , analytical chemistry (journal) , optoelectronics , chemistry , nanotechnology , physics , layer (electronics) , chromatography , composite material
Results of measurements made at the SIRIUS beamline of the SOLEIL synchrotron for a new X‐ray beam position monitor based on a super‐thin single crystal of diamond grown by chemical vapor deposition (CVD) are presented. This detector is a quadrant electrode design processed on a 3 µm‐thick membrane obtained by argon–oxygen plasma etching the central area of a CVD‐grown diamond plate of 60 µm thickness. The membrane transmits more than 50% of the incident 1.3 keV energy X‐ray beam. The diamond plate was of moderate purity (∼1 p.p.m. nitrogen), but the X‐ray beam induced current (XBIC) measurements nevertheless showed a photo‐charge collection efficiency approaching 100% for an electric field of 2 V µm −1 , corresponding to an applied bias voltage of only 6 V. XBIC mapping of the membrane showed an inhomogeneity of more than 10% across the membrane, corresponding to the measured variation in the thickness of the diamond plate before the plasma etching process. The measured XBIC signal‐to‐dark‐current ratio of the device was greater than 10 5 , and the X‐ray beam position resolution of the device was better than a micrometer for a 1 kHz sampling rate.