Radiation monitoring with CVD diamonds in BABAR Edwards, A.J.; Bruinsma, M.; Burchat, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2005, Letnik:
552, Številka:
1
Journal Article
Recenzirano
The BABAR experiment has been using two polycrystalline chemical-vapor-deposition (pCVD) diamonds for radiation monitoring for nearly 2 years. In July 2005, an additional 12 diamond based radiation ...sensors will be installed inside the BABAR detector. These diamonds will take over the function of 12 silicon PIN-diodes that are currently used in the radiation protection and monitoring system. We describe our highly successful experience with using pCVD diamond radiation sensors in a high energy physics experiment. We also detail our findings of persistent signal currents and magnetically suppressed erratic dark currents in pCVD diamond based radiation sensors.
Radiation monitoring with diamond sensors in BABAR Edwards, A.J.; Brau, B.; Bruinsma, M. ...
IEEE transactions on nuclear science,
2004-Aug., 2004-08-00, 20040801, Letnik:
51, Številka:
4
Journal Article
Recenzirano
In order to safeguard the silicon vertex tracker in the BABAR detector from excessive radiation damage, cumulative dose and instantaneous dose rates are continuously monitored. As an upgrade to the ...current radiation monitoring system, which uses silicon p-i-n diodes, we are examining the possible use of single-crystal and/or polycrystalline chemical vapor deposition (CVD) diamonds. The radiation responses of several CVD diamonds have been tested on time scales from tens of nanoseconds to thousands of seconds in order to determine their integrity in monitoring accumulated doses and their response to large sudden changes in dose rates. Two polycrystalline CVD diamonds have been installed near the silicon vertex tracker near existing silicon p-i-n diodes for comparative studies. CVD diamond radiation sensors have also been tested using /sup 60/Co and in various magnetic field configurations.
Current and future imaging surveys will measure cosmic shear with a statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been ...achieved to date. We investigate the effects of using the point spread function (PSF) measured with stars to determine the shape of a galaxy that has a different spectral energy distribution (SED) than the star. We demonstrate that a wavelength dependent PSF size, for example as may originate from atmospheric seeing or the diffraction limit of the primary aperture, can introduce significant shape measurement biases. This analysis shows that even small wavelength dependencies in the PSF may introduce biases, and hence that achieving the ultimate precision for weak lensing from current and future imaging surveys will require a detailed understanding of the wavelength dependence of the PSF from all sources, including the CCD sensors.
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