For ALICE spectator protons and neutrons will be separated from ion beams, using a separator magnet (D1) of the LHC beam optics and respectively detected by a proton and a neutron "Zero-degree ...Calorimeter" (ZDC). An electromagnetic calorimeter is also foreseen for the measurement of the forward photons coming from the decay of /spl pi//sup 0/. The calorimeter performances are discussed.
The results obtained by the Slim5 collaboration on a low material budget tracking silicon demonstrator put on a 12
GeV/
c
proton test beam at CERN are reported. Inside a reference telescope, two ...different and innovative detectors were placed for careful tests. The first was a 4k-Pixel Matrix of Deep N Well MAPS, developed in a 130
nm CMOS Technology, square pixels
50
μ
m
wide, thinned down to
100
μ
m
and equipped with a digital sparsified readout running up to 50
MHz. The other was a high resistivity double sided silicon detector,
200
μ
m
thick, with short strips with
50
μ
m
pitch at
45
∘
angle to the detector's edge. The detectors were equipped with dedicated fast readout architectures performing on-chip data sparsification and providing the timing information for the hits. The criteria followed in the design of the pixel sensor and of the pixel readout architecture will be reviewed. Preliminary measurements of the pixel charge collection, track detection efficiencies and resolutions of pixel and strip sensors are discussed.
The data driven architecture of the readout chips has been fully exploited in the test beam by a data acquisition system able to collect on electronic board up to 2.5 Million events per second before triggering. By using a dedicated Associative Memory board, we were able to perform a level 1 trigger system, with minimal latency, identifying cleanly tracks traversing the detectors. System architecture and main performances are shown.
The trigger for the ALICE muon spectrometer will be issued by single-gap, low resistivity bakelite resistive plate chambers (RPCs). The trigger system consists of four
5.5
×
6.5
m
2
RPC planes ...arranged in two stations, for a total of 72 detectors.
One hundred and sixteen detectors have been assembled and tested in Torino. The tests have been performed with the streamer mixture developed for heavy ion data-taking. The tests include: the detection of gas leaks and parasitic currents; the measurement of the efficiency with cosmic rays, with particular regard to the uniformity of the efficiency throughout the whole active surface, with a granularity of about
2
×
2
cm
2
; the measurement of the dark current and of the mean and localised noise rate.
All the RPCs produced have been characterised. Among them, the detectors to be finally installed in ALICE and some spare have been selected; 17% of all the produced detectors have been discarded.
A short description of the test set-up is given. The results of the tests are presented, with particular regard to the performance of the selected detectors.
The trigger detectors for the Muon Forward Spectrometer of the ALICE experiment will be single gap RPCs with low-resistivity bakelite electrodes. The detector will take data for different colliding ...systems resulting in a wide range of working conditions and requirements, especially concerning position resolution and lifetime. To this aim we have investigated the possibility to operate the RPCs both in streamer and in saturated avalanche mode with the same FE electronics. The study of the detector performance after long irradiation periods has been carried out at the Gamma Irradiation Facility at CERN with different gas mixtures: a quenched streamer gas mixture (51.5% Ar, 41.3% forane, 7.2% C/sub 2/H/sub 10/ and 1% SF/sub 6/) and a saturated avalanche mixture (88% forane, 10% C/sub 2/H/sub 10/ and 2% SF/sub 6/). We present the results of the ageing test of a final RPC in "ALICE-like" irradiation conditions using the streamer gas mixture and the results of the ageing test of a small prototype with the avalanche gas mixture.
The S uperB silicon vertex tracker Forti, F.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2011, Letnik:
636, Številka:
1
Journal Article
Recenzirano
The S
uperB asymmetric e
+e
− collider, to be built near the INFN National Frascati Laboratory in Italy, has been designed to deliver a luminosity greater than 10
36
cm
−2
s
−1 with moderate beam ...currents, allowing precision measurements in the flavour sector sensitive to New Physics. The conceptual design of the Silicon Vertex Tracker for the S
uperB Detector is presented, based on double-sided silicon strip detectors for the outer layers, with the addition of an innermost Layer 0 close to the interaction point, with low material budget and capable of sustaining a background rate of several MHz/cm
2.
ALICE (a large ion collider experiment) is the heavy-ion dedicated experiment at LHC. The resistive plate chamber detector (RPC) with low-resistivity bakelite electrodes was selected for the trigger ...system of the muon spectrometer. Although the main goal of ALICE is the study of nucleus-nucleus collisions, reference data in p-p interactions will be collected as well. If, on one hand, RPC operation in streamer mode is adequate for data taking with ion beams, on the other hand, the more severe ageing requirements for p-p data taking lead us to explore the possibility of operating the detector in "highly-saturated avalanche" regime. A detailed study of the signal was carried out with cosmic rays to get a more precise view of the intrinsic properties of the gas mixture (among others the streamer fraction vs. HV). The possibility of detecting avalanche signals with our FEE designed for the streamer mode was successfully investigated. Furthermore, tests with muon beam at CERN were carried out with satisfactory results in terms of efficiency, time resolution and cluster size. An analysis of the exhaust gas showed a low HF content: this is an encouraging result in view of long term stability of the detector which is at present under test.
Deep n-well MAPS in a 130nm CMOS technology: Beam test results Neri, N.; Avanzini, C.; Batignani, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
We report on recent beam test results for the APSEL4D chip, a new deep n-well MAPS prototype with a full in-pixel signal processing chain obtained by exploiting the triple well option of the CMOS ...0.13μm process. The APSEL4D chip consists of a 4096 pixel matrix (32 rows and 128 columns) with 50×50μm2 pixel cell area, with custom readout architecture capable of performing data sparsification at pixel level. APSEL4D has been characterized in terms of charge collection efficiency and intrinsic spatial resolution under different conditions of discriminator threshold settings using a 12GeV/c proton beam in the T9 area of the CERN PS. We observe a maximum hit efficiency of 92% and we estimate an intrinsic resolution of about 14μm. The data driven approach of the tracking detector readout chips has been successfully used to demonstrate the possibility to build a Level 1 trigger system based on associative memories. The analysis of the beam test data is critically reviewed along with the characterization of the device under test.
The proton zero degree calorimeter (ZP) for the ALICE experiment will measure the energy of the spectator protons in heavy ion collisions. The ZP is a spaghetti calorimeter, which collects and ...measures the Cherenkov light produced by the shower particles in silica optical fibres embedded in a brass absorber. The details of its construction will be shown. The calorimeter has been tested at the CERN SPS in July 2004 with pion and electron beams of various momenta ranging from 50 to 200 GeV/c. The linearity of the response of the calorimeter and its energy resolution as a function of the beam energy have been measured. The preliminary results of the test are presented.
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