Performance of the prototype of the electromagnetic calorimeter for PANDA Kavatsyuk, M.; Bremer, D.; Dormenev, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2011, Letnik:
648, Številka:
1
Journal Article
Recenzirano
The PANDA collaboration at FAIR, Germany, will employ antiproton annihilations to investigate yet undiscovered charm-meson states and glueballs. The aim is to study QCD phenomena in the ...non-perturbative regime and to unravel the origin of hadronic masses. A multi-purpose detector for tracking, calorimetry and particle identification is presently being developed to run at high luminosities providing up to 2×107 interactions/s. One of the crucial components of the PANDA spectrometer is the Electromagnetic Calorimeter, composed of cooled PbWO4 crystals. This paper describes construction and performance of a fully functioning prototype of this calorimeter. The performance was determined from measurements exploiting cosmic muons and high-energy tagged photons from the MAMI-C electron accelerator. The response measurements were carried out using sampling ADCs and, for comparison, charge-integrating ADCs. The achieved results validate the usage of sampling ADCs with a moderate sampling frequency, provide the energy resolution as foreseen in the Technical Design Report of the full calorimeter, and secure event correlation by achieving a good timing resolution through digital analysis of the sampled signals.
A simple, efficient, and robust feature-extraction algorithm, developed for the digital front-end electronics of the electromagnetic calorimeter of the PANDA spectrometer at FAIR, Darmstadt, is ...implemented in VHDL for a commercial 16 bit 100
MHz sampling ADC. The source-code is available as an open-source project and is adaptable for other projects and sampling ADCs. Best performance with different types of signal sources can be achieved through flexible parameter selection. The on-line data-processing in FPGA enables to construct an almost dead-time free data acquisition system which is successfully evaluated as a first step towards building a complete trigger-less readout chain. Prototype setups are studied to determine the dead-time of the implemented algorithm, the rate of false triggering, timing performance, and event correlations.
A statistical combination of the experimental lifetime estimations available in the literatures is performed for 3ΛH and 4ΛH, including several recent measurements. The combined average values of the ...lifetime for 3ΛH and 4ΛH are respectively 216−16+19 ps and 192−18+20 ps with a reduced χ2 of 0.89 and 0.48. A new insight into the lifetime estimation of the HypHI Phase 0 experiment by a Bayesian approach is also presented. In this approach, several different prior distributions including the combination of previous lifetime data and a Jeffrey prior are used. The principal mode and the smallest credible interval at 68% of the posterior distribution, given by the prior belief of the previous measurements, are 217−16+19 ps and 194−18+20 ps respectively for 3ΛH and 4ΛH. The two employed approaches have revealed that the lifetime of hypernuclei 3ΛH and 4ΛH can be shorter than the Λ–hyperon lifetime.
The performance of the most recent prototypes of the ANDA barrel electromagnetic calorimeter (EMC) will be compared. The first large scale prototype PROTO60 was designed to test the performance of ...the improved tapered lead tungstate crystals (PWO-II). The PROTO60 which consists of 6 × 10 crystals was tested at various accelerator facilities over the complete envisaged energy range fulfilling the requirements of the TDR of the ANDA EMC in terms of energy, position and time resolution. To realize the final barrel geometry and to test the final front end electronics, a second prototype PROTO120 has been constructed. It represents a larger section of a barrel slice, containing the most tapered crystals and the close to final components for the ANDA EMC. The performance of both prototypes will be compared with a focus on the analysis procedure including the signal extraction, noise rejection, calibration and the energy resolution. In addition, the influence of the non-uniformity of the crystal on the energy resolution will be discussed.
Hypernuclear production cross sections have been deduced for the first time with induced reaction of heavy ion beam on fixed target and by means of the invariant mass method by the HypHI ...Collaboration exploiting the reaction of 6Li + 12C at 2A GeV or sNN=2.70 GeV. A production cross section of 3.9±1.4 μb for 3ΛH and of 3.1±1.0 μb for 4ΛH respectively in the projectile rapidity region was inferred as well as the total production cross section of the Λ hyperon was measured and found to be equal to 1.7±0.8 mb. A global fit based on a Bayesian approach was performed in order to include and propagate statistical and systematic uncertainties. Production ratios of 3ΛH/4ΛH, 3ΛH/Λ and 4ΛH/Λ were included in the inference procedure. The strangeness population factors S3 and S4 of 3ΛH and 4ΛH respectively were extracted. In addition, the multiplicities of the Λ hyperon, 3ΛH, and 4ΛH together with the rapidity and transversal momentum density distributions of the observed hypernuclei were extracted and reported.
Tests of optical glues for the PANDA electromagnetic calorimeter Dbeyssi, A.; Tomasi-Gustafsson, E.; Hennino, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2013, Letnik:
722
Journal Article
Recenzirano
This paper reports on the results of tests for low temperature applications of two commercial optical glues in the electromagnetic calorimeter of PANDA at FAIR. Mechanical, thermal and optical ...properties are presented, as well as radiation hardness to photon and proton radiation.
Event reconstruction methods for the HypHI Phase 0 experiment at GSI Rappold, C.; Saito, T.R.; Bianchin, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2010, Letnik:
622, Številka:
1
Journal Article
Recenzirano
The first experiment of the HypHI project, Phase 0, at GSI-Darmstadt performs the feasibility study of precise hypernuclear spectroscopy with heavy ion induced reactions by using the collision of 6Li ...at 2 A GeV on a 12C target. In preparation of the Phase 0 experiment, simulation studies have been performed with a dedicated event reconstruction procedure. Details of this procedure will be discussed in this paper as well as the physics motivation of the Phase 0 and the experimental setup used during simulations. Expected results of the experiment will also be discussed.
The use of High Purity Germanium detectors (HPGe) has been planned in some future experiments of hadronic physics. The crystals will be located close to large spectrometers where the magnetic ...fringing field will not be negligible and their performances might change. Moreover high precision is required in these experiments. The contribution of magnetic field presence and long term measurements is unique. In this paper the results of systematic measurements of the resolution, stability and efficiency of a crystal operating inside a magnetic field of 0.8
T, using radioactive sources in the energy range from 0.08 to 1.33
MeV, are reported. The measurements have been repeated during several months in order to test if any permanent damage occurred. The resolution at 1.117 and 1.332
MeV gamma-rays from a
60Co source has been measured at different magnetic fields in the range of 0–0.8
T and the results are compared with the previous data.
The HypHI Phase 0 experiment with
6
Li projectiles at 2
A
GeV on a carbon target has been performed at GSI in order to demonstrate the feasibility of hypernuclear spectroscopy with induced reaction ...of heavy ion beams. Current data analyses have shown peaks in invariant mass distributions of p + π
−
for
Λ
,
3
He+ π
−
for
3
Λ
H and
4
He + π
−
for
4
Λ
H. Lifetime values for the corresponding peaks have been also deduced, which are in good agreement with the former known values.
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