Very high momentum particle identification in ALICE at the LHC Agocs, A.; Alfaro, R.; Barnafoldi, G.G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Volume:
617, Issue:
1
Journal Article
Peer reviewed
We propose to construct and install a limited acceptance detector to identify hadrons (pions, K, p) up to 30
GeV/
c on a track-by-track basis in space available in ALICE. Details and PID performance ...simulation results will be presented for two possible options, including a high transverse momentum (
p
T
) trigger for this detector. The first option is a RICH design with a
C
4
F
10
gas UV-photon radiator, UV-mirror, quartz window and pad-readout. This design requires additional tracking detectors to enable high
p
T
triggering. A second option is a combination of three detectors: a RICH with
CF
4
gas both as a UV-photon radiator and as a gas amplification medium (a windowless approach); and a threshold Cherenkov detector (
C
4
F
10
) with a quartz window and pad readout. The response for minimum ionizing particles (MIP) and UV-photons in these detectors can be well separated. With an additional tracking detector this design will also provide high
p
T
triggering. The simulation includes UV-photon production due to
CF
4
scintillation.
The energy density is the prime parameter to define the deconfinement of quarks and gluons occurring in collisions of heavy ions. Recently, there is mounting evidence that many observables in ...proton-proton collisions behave in a manner very similar to the one observed in heavy ions. We present as an additional piece of evidence, a scaling of the strange particle yields as a function of the energy density of the three collision systems: p+p p+Pb and Pb+Pb, using the latest results of the ALICE collaboration.
Buried plastic scintillator muon telescope (BATATA) Alfaro, R.; De Donato, C.; D’Olivo, J.C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Volume:
617, Issue:
1
Journal Article
Peer reviewed
Muon telescopes have multiple applications in the area of cosmic ray research. We are currently building such a detector with the objective of comparing the ground penetration of muon vs. ...electron-gamma signals originated in cosmic ray showers. The detector is composed by a set of three parallel dual-layer scintillator planes, buried at fixed depths ranging from 120 to
600
g
/
cm
2
. Each layer is
4
m
2
and is composed by 49 rectangular strips of
4
cm
×
2
m
, oriented at a
90
∘
angle with respect to its companion layer, which gives an
xy
-coincidence
pixel of
4
×
4
cm
2
. The scintillators are MINOS extruded polystyrene strips, with an embedded Bicron BC92 wavelength shifting (WLS) fibers, of 1.5
mm in diameter. Light is collected by Hamamatsu H7546B multi-anode PMTs of 64 pixels. The front-end (FE) electronics works in counting mode and signals are transmitted to the surface DAQ stage using low-voltage differential signaling (LVDS). Any strip signal above threshold opens a GPS-tagged
2
μ
s
data collection window. Data, including signal and background, are acquired by a system of FPGA (Spartan 2E) boards and a single-board computer (TS7800).
.
A new detector concept has been investigated to extend the capabilities of heavy-ion collider experiments, represented here through the ALICE detector, in the high transverse momentum (
p
T
region. ...The resulting Very High Momentum Particle Identification Detector (VHMPID) performs charged hadron identification on a track-by-track basis in the 5 GeV/
c
<
p
< 25 GeV/
c
momentum range and provides heavy-ion experiments with new opportunities to study parton-medium interactions at RHIC and LHC energies, where the creation of deconfined quark-gluon matter has been established. The detector is based on novel advances to the pressurized gaseous ring imaging Cherenkov (RICH) concept, which yield a very compact, high resolution addition to existing heavy-ion experiments. We conclude that in order for the device to yield statistically significant results not only for single particle measurements, but also for di-hadron and jet-tagged correlation studies, it has to cover contiguously up to 30% of a central barrel detector in radial direction. This will allow, for the first time, identified charged hadron measurements in jets. In this paper we summarize the physics motivations for such a device, as well as its conceptual design, layout, and integration into ALICE.
A pattern recognition method developed for the High Momentum Particle IDentification (HMPID) detector in the ALICE experiment at CERN is presented. The algorithm is based on the Hough transform with ...a mapping of the pad coordinate space directly to the Cherenkov angle parameter space. Cherenkov angle reconstruction has been studied as a function of different particle densities in the photodetector using real data taken in the ALICE tests at the CERN SPS: a satisfactory resolution can be achieved even in events where the occupancy reaches more than 12%, which is the situation we may be confronted with in central Pb–Pb interactions at LHC.
ACORDE a cosmic ray detector for ALICE Fernández, A.; Gámez, E.; Herrera, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2007, Volume:
572, Issue:
1
Journal Article
Peer reviewed
Open access
ACORDE is one of the ALICE detectors, presently under construction at CERN. It consists of an array of plastic scintillator counters placed on the three upper faces of the ALICE magnet. It will act ...as a cosmic ray trigger, and, together with other ALICE sub-detectors, will provide precise information on cosmic rays with primary energies around
10
15
–
10
17
eV
. Here we describe the design of ACORDE along with the present status and integration into ALICE.
We present a threshold aerogel detector that uses only the unscattered light in the aerogel, focused on a photomultiplier using a Fresnel lens. The results with n = 1.03 and 3 photomultiplier are ...presented. The possibility to use 1.5 PMT is discussed.
A threshold imaging Cherenkov detector with CsI photocathodes Braem, A.; Fabjan, C.W.; Franz, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1998, Volume:
409, Issue:
1-3
Journal Article
Peer reviewed
Open access
A Threshold Imaging Cherenkov (TIC) detector, in conjunction with a tracking device and a time-of-flight system, has been developed to allow pion, kaon and proton identification in the 3–8GeV/c range ...of momenta. The system allows spatial identification of the photons of particles above the Cherenkov threshold and their correlation to a particular track. The TIC detector uses a MWPC detector with a CsI coated photocathode for photon conversion. The results obtained in ultrarelativistic lead–lead collisions at the CERN SPS accelerator are presented.
The current progress of the ALICE Ring Imaging Cherenkov Detector Braem, A.; De Cataldo, G.; Davenport, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Volume:
580, Issue:
2
Journal Article
Peer reviewed
Open access
Recently, the last two modules (out of seven) of the ALICE High Momentum Particle Identification Detector (HMPID) were assembled and tested. The full detector, after a pre-commissioning phase, has ...been installed in the experimental area, inside the ALICE solenoid, at the end of September 2006. In this paper, we review the status of the ALICE/HMPID project and we present a summary of the series production of the CsI photo-cathodes. We describe the key features of the production procedure which ensures high-quality photo-cathodes as well as the results of the quality assessment performed by means of a specially developed 2D scanner system able to produce a detailed map of the CsI photo-current over the entire photo-cathode surface.
Finally, we present our recent R&D efforts toward the development of a novel generation of imaging Cherenkov detectors with the aim to identify, in heavy-ion collisions, hadrons up to 30
GeV/
c.
We present here an exhaustive study of the possibilities offered by a combination of a gas radiator of the highest index of refraction commercially available
(
C
5
F
12
)
with the proven concept of ...large area CsI photocathodes instrumenting either a multiwire chamber or a GEM detector. We will present two geometries. One of them is proximity-focusing, nevertheless allows identification in a large momentum range. The second geometry deals with the possibilities of using focusing with a spherical mirror. Simulations of the performance are presented.
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