6,227 research outputs found
Neutron irradiation effect on SiPMs up to = 5 10 cm
Silicon Photo-Multipliers (SiPM) are becoming the photo-detector of choice
for increasingly more particle detection applications, from fundamental physics
to medical and societal applications. One major consideration for their use at
high-luminosity colliders is the radiation damage induced by hadrons, which
leads to a dramatic increase of the dark count rate. KETEK SiPMs have been
exposed to various fluences of reactor neutrons up to =
510 cm (1 MeV equivalent neutrons). Results from the I-V,
and C-V measurements for temperatures between 30C and 30C
are presented. We propose a new method to quantify the effect of radiation
damage on the SiPM performance. Using the measured dark current the single
pixel occupation probability as a function of temperature and excess voltage is
determined. From the pixel occupation probability the operating conditions for
given requirements can be optimized. The method is qualitatively verified using
current measurements with the SiPM illuminated by blue LED light
Test Results on the Silicon Pixel Detector for the TTF-FEL Beam Trajectory Monitor
Test measurements on the silicon pixel detector for the beam trajectory
monitor at the free electron laser of the TESLA test facility are presented. To
determine the electronic noise of detector and read-out and to calibrate the
signal amplitude of different pixels the 6 keV photons of the manganese K line
are used. Two different methods determine the spatial accuracy of the detector:
In one setup a laser beam is focused to a straight line and moved across the
pixel structure. In the other the detector is scanned using a low-intensity
electron beam of an electron microscope. Both methods show that the symmetry
axis of the detector defines a straight line within 0.4 microns. The
sensitivity of the detector to low energy X-rays is measured using a vacuum
ultraviolet beam at the synchrotron light source HASYLAB. Additionally, the
electron microscope is used to study the radiation hardness of the detector.Comment: 14 pages (Latex), 13 figures (Postscript), submitted to Nuclear
Instruments and Methods
Beam Test of Silicon Strip Sensors for the ZEUS Micro Vertex Detector
For the HERA upgrade, the ZEUS experiment has designed and installed a high
precision Micro Vertex Detector (MVD) using single sided micro-strip sensors
with capacitive charge division. The sensors have a readout pitch of 120
microns, with five intermediate strips (20 micron strip pitch). An extensive
test program has been carried out at the DESY-II testbeam facility. In this
paper we describe the setup developed to test the ZEUS MVD sensors and the
results obtained on both irradiated and non-irradiated single sided micro-strip
detectors with rectangular and trapezoidal geometries. The performances of the
sensors coupled to the readout electronics (HELIX chip, version 2.2) have been
studied in detail, achieving a good description by a Monte Carlo simulation.
Measurements of the position resolution as a function of the angle of incidence
are presented, focusing in particular on the comparison between standard and
newly developed reconstruction algorithms.Comment: 41 pages, 21 figures, 2 tables, accepted for publication in NIM
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