Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements ...from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (
p
T
), elliptic flow, two-particle correlations, nonstatistical fluctuations, and suppression of particle production at high
p
T
. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.
We present the first beam test results of a real size prototype RPC for the endcap region of the CMS, one of large detectors at CERN LHC. The chamber was built with relatively low resistivity ...bakelite made in Korea and was operated successfully at the Gamma Irradiation Facility at CERN under the highest photon flux available, which corresponds to an effective cluster rate up to about
800
Hz/
cm
2
. The cross-talk effects between strips and sectors have been studied extensively. The high voltage plateau, which satisfies the CMS requirements for efficiency and the number of strips fired per cluster, extends to at least
300
V
. The time resolution has been measured to be better than
1.3
ns
in this HV plateau region. These results demonstrate that the current design of the device can be used as a muon trigger detector for the CMS forward region.
This paper presents data obtained in a systematic study on the bulk resistivity of Korean bakelite as a function of temperature in the range 20–30°C and relative humidity in the range 35–65%. Strong ...dependence of resistivity on both temperature and humidity was observed. Measurements were carried out in the framework of R&D work on Resistive Plate Chambers (RPCs) which will be used in the CMS detector.
This paper presents the results from cosmic ray tests performed in the framework of
R&
D
effort on the forward Resistive Plate Chamber (RPC) for CMS. A double gap RPC of dimensions
50×50
cm
2
with 2 ...mm gas gaps was tested. We report data on the use of tetrafluorethane-based gas mixture, with additions of water vapour and SF
6. Efficiency, time resolution and cross-talk behaviour of the detector were investigated.
We present the results from cosmic ray tests on the forward Resistive Plate Chamber (RPC) for the CMS. Double-gap prototype RPC were built and tested in the Korea Detector Laboratory (KODEL). We ...found that addition of SF
6 and water vapor to the tetrafluorethane-based gas mixture was required for the long-term stable operation of RPC. Efficiency, time resolution as well as cross-talk behavior of the detector were investigated. In addition, we present the temperature and humidity dependence of bulk resistivity of Korean bakelite in detail.
Beam test result of a large real-size RPC for the CMS/LHC experiment Ahn, S.H; Amirikas, R; Bahk, S.Y ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2000, Letnik:
456, Številka:
1
Journal Article
Recenzirano
In this report, first beam test results for a real size RE2-2 prototype RPC for the forward region of the CERN CMS are presented. The beam test for the prototype RPC was performed at the Gamma ...Irradiation Facility (GIF) in CERN with a particle rate ranging up to
∼700
Hz/
cm
2
. These test results demonstrate that a real size RE2-2 RPC can be built with relatively low resistivity of bakelite (∼10
10
Ω
cm). The current design of the RPC can be an option for the CMS forward region with its good efficiency and time characteristics under high radiation environment.
In this paper, 'http://vibration.desy.de', used as a tool for the storage and dissemination of ground motion measurement database of 20 sites around the world and the vibration stability data of ...superconducting modules for the European X-ray Free Electron Laser (XFEL) and the proposed International Linear Collider (ILC) is introduced. This homepage is open to the scientific community and the data can be utilized for planning of future accelerator facilities and design of future prototypes of module vessels containing cold mass.
Both the European X-ray free electron laser (XFEL) 1 and the proposed International linear collider (ILC) 2 will rely on superconducting accelerating modules (cryomodules) for their linear ...accelerator (linac) section/s. In this paper, vibration stability studies of a type III cryomodule with relation to its mechanical design, at room temperature, have been presented. Results of this study are relevant for the design of both the XFEL and the ILC module prototypes.
A new method for low level low frequency vibration measurements in the cryogenic environment is presented. Commercial moving coil seismometers (geophones) have been used to investigate the mechanical ...stability of the quadrupole of a third generation (so-called Type-III) FLASH cryomodule (named Module 6) in fully operating conditions. Geophones were able to operate at 4.5 K without any loss of performance, providing nanometer level resolution even in the 1-10 Hz frequency band, region not covered by existing data because of the reduced sensitivity of the cooled piezoelectric accelerometers 1. A preliminary evaluation of the impact of the refrigeration system and of the high power RF on the vibration level of the quadrupole is also presented. The results are of interest for the design of linear accelerator (linac) cryomodules of the International Linear Collider (ILC) 2 and of the European X-ray Free Electron Laser (XFEL) 3, for which the design is a further evolution of the FLASH Type III.
Event anisotropy is expected to have sensitivity to the early stage of ultra-relativistic heavy-ion collisions at RHIC. The possible formation of a quark gluon plasma (QGP) could affect how the ...initial anisotropy in the space coordinate is transfered into the momentum space for the initial state. The anisotropy parameter (v
2) is an amplitude of the 2nd harmonic parameter of the azimuthal distribution with respect to the reaction plane. We present here v
2 of identified and inclusive charged particles measured in the PHENIX central arm detector (∣η∣ < 0.35) with respect to the reaction plane defined at ∣η∣ = 3 ∼ 4 in 200 GeV Au + Au collisions. We find that v
2 increases from central to mid-central collisions reaching a maximum at about 50% of the geometric cross section and then decreases again for more peripheral collisions. As a function of transverse momentum in minimum-bias collisions, the v
2 parameter increases linearly with p
T up to p
T ≅ 2 GeV/c and then saturates for inclusive charged particles. the v
2 parameter of identified particles (π
+, π
−,
K
+,
K
−,
p and
p
¯
follow a hydro-dynamic behavior up to 2 GeV/c in p
T, where the lighter mass particles haver larger v
2 at a given p
T. However there is an indication that this trend is reversed at around p
T ≅ 2GeV/c, where
p and
p
¯
have larger v
2 than π and
K.
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