17 research outputs found
Scintillation counter with MRS APD light readout
START, a high-efficiency and low-noise scintillation detector for ionizing
particles, was developed for the purpose of creating a high-granular system for
triggering cosmic muons. Scintillation light in START is detected by MRS APDs
(Avalanche Photo-Diodes with Metal-Resistance-Semiconductor structure),
operated in the Geiger mode, which have 1 mm^2 sensitive areas. START is
assembled from a 15 x 15 x 1 cm^3 scintillating plastic plate, two MRS APDs and
two pieces of wavelength-shifting optical fiber stacked in circular coils
inside the plastic. The front-end electronic card is mounted directly on the
detector. Tests with START have confirmed its operational consistency, over 99%
efficiency of MIP registration and good homogeneity. START demonstrates a low
intrinsic noise of about 10^{-2} Hz. If these detectors are to be
mass-produced, the cost of a mosaic array of STARTs is estimated at a moderate
level of 2-3 kUSD/m^2.Comment: 6 pages, 5 figure
RPC with low-resistive phosphate glass electrodes as a candidate for the CBM TOF
Usage of electrodes made of glass with low bulk resistivity seems to be a
promising way to adapt the Resistive Plate Chambers (RPC) to the high-rate
environment of the upcoming CBM experiment. A pilot four-gap RPC sample with
electrodes made of phosphate glass, which has bulk resistivity in the order of
10^10 Ohm cm, has been studied with MIP beam for TOF applications. The tests
have yielded satisfactory results: the efficiency remains above 95% and the
time resolution stays within 120 ps up to the particle rate of 18 kHz/cm2. The
increase in rate from 2.25 to 18 kHz/cm2 leads to an increase of estimated
"tails" fraction in the time spectrum from 1.5% to 4%.Comment: 8 pages, 6 figures, submitted to Elsevier Scienc
START as the detector of choice for large-scale muon triggering systems
Further progress in building high-granular large-scale systems based on Scintillation Tiles with MRS APD light readout (START) became possible thanks to the creation of an improved version of MRS APD. The cost of the system may now be significantly reduced by using inexpensive extruded scintillator. More than 160 START samples were assembled based on this design modification and proved to possess 100% MIP detection efficiency and the intrinsic noise rate of less than 0.08 Hz. Long-term stability of START characteristics was confirmed after 3.5 months of operation
Study of QGP signatures with the phi->K+K- signal in Pb-Pb ALICE events
The phi->K+K- decay channel in Pb-Pb collisions at LHC is studied through a
full simulation of the ALICE detector. The study focuses on possible signatures
in this channel of quark-gluon plasma (QGP) formation. On a basis of 10^6
collisions at high centrality some proposed QGP signatures are clearly visible
both in K+K- invariant mass and transverse mass distributions. The high
significance of this observation appears to reside heavily on the use of the
TOF (Time Of Flight) system of ALICE in addition to its central tracking
detectors.Comment: 9 pages, 7 figures, to appear in EPJ
Magnetic Field and Radiation Tests of a Programmable Delay Line
Programmable Delay Lines (PDLs) are widely used in trigger systems. We performed tests under radiation and magnetic field for the chip 3D3418-0.25, to be used in the ALICE-TOF trigger system. The tests showed that this chip can comfortably operate in a 0.6 T magnetic field and tolerate a dose larger than 446 G