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First measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasi-elastic-like interactions using an accelerator neutrino beam
Authors:
T2K Collaboration,
K. Abe,
S. Abe,
R. Akutsu,
H. Alarakia-Charles,
Y. I. Alj Hakim,
S. Alonso Monsalve,
L. Anthony,
M. Antonova,
S. Aoki,
K. A. Apte,
T. Arai,
T. Arihara,
S. Arimoto,
Y. Asada,
Y. Ashida,
N. Babu,
G. Barr,
D. Barrow,
P. Bates,
M. Batkiewicz-Kwasniak,
V. Berardi,
L. Berns,
S. Bordoni,
S. B. Boyd
, et al. (314 additional authors not shown)
Abstract:
We report the first measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasi-elastic-like interactions at the gadolinium-loaded Super-Kamiokande detector using the T2K neutrino beam, which has a peak energy of about 0.6 GeV. A total of 30 neutral-current quasi-elastic-like event candidates were selected from T2K data corresponding to an exposure of $1.76\times10^{20}$ p…
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We report the first measurement of neutron capture multiplicity in neutrino-oxygen neutral-current quasi-elastic-like interactions at the gadolinium-loaded Super-Kamiokande detector using the T2K neutrino beam, which has a peak energy of about 0.6 GeV. A total of 30 neutral-current quasi-elastic-like event candidates were selected from T2K data corresponding to an exposure of $1.76\times10^{20}$ protons on target. The $γ$ ray signals resulting from neutron captures were identified using a neural network. The flux-averaged mean neutron capture multiplicity was measured to be $1.37\pm0.33\text{ (stat.)}$$^{+0.17}_{-0.27}\text{ (syst.)}$, which is compatible within $2.3\,σ$ than predictions obtained using our nominal simulation. We discuss potential sources of systematic uncertainty in the prediction and demonstrate that a significant portion of this discrepancy arises from the modeling of hadron-nucleus interactions in the detector medium.
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Submitted 30 May, 2025; v1 submitted 28 May, 2025;
originally announced May 2025.
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Scintillator ageing of the T2K near detectors from 2010 to 2021
Authors:
The T2K Collaboration,
K. Abe,
N. Akhlaq,
R. Akutsu,
A. Ali,
C. Alt,
C. Andreopoulos,
M. Antonova,
S. Aoki,
T. Arihara,
Y. Asada,
Y. Ashida,
E. T. Atkin,
S. Ban,
M. Barbi,
G. J. Barker,
G. Barr,
D. Barrow,
M. Batkiewicz-Kwasniak,
F. Bench,
V. Berardi,
L. Berns,
S. Bhadra,
A. Blanchet,
A. Blondel
, et al. (333 additional authors not shown)
Abstract:
The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9--2.2\% per year. Extrapolation of the degradation…
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The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9--2.2\% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator.
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Submitted 26 July, 2022;
originally announced July 2022.
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Supernova Model Discrimination with Hyper-Kamiokande
Authors:
Hyper-Kamiokande Collaboration,
:,
K. Abe,
P. Adrich,
H. Aihara,
R. Akutsu,
I. Alekseev,
A. Ali,
F. Ameli,
I. Anghel,
L. H. V. Anthony,
M. Antonova,
A. Araya,
Y. Asaoka,
Y. Ashida,
V. Aushev,
F. Ballester,
I. Bandac,
M. Barbi,
G. J. Barker,
G. Barr,
M. Batkiewicz-Kwasniak,
M. Bellato,
V. Berardi,
M. Bergevin
, et al. (478 additional authors not shown)
Abstract:
Core-collapse supernovae are among the most magnificent events in the observable universe. They produce many of the chemical elements necessary for life to exist and their remnants -- neutron stars and black holes -- are interesting astrophysical objects in their own right. However, despite millennia of observations and almost a century of astrophysical study, the explosion mechanism of core-colla…
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Core-collapse supernovae are among the most magnificent events in the observable universe. They produce many of the chemical elements necessary for life to exist and their remnants -- neutron stars and black holes -- are interesting astrophysical objects in their own right. However, despite millennia of observations and almost a century of astrophysical study, the explosion mechanism of core-collapse supernovae is not yet well understood. Hyper-Kamiokande is a next-generation neutrino detector that will be able to observe the neutrino flux from the next galactic core-collapse supernova in unprecedented detail. We focus on the first 500 ms of the neutrino burst, corresponding to the accretion phase, and use a newly-developed, high-precision supernova event generator to simulate Hyper-Kamiokande's response to five different supernova models. We show that Hyper-Kamiokande will be able to distinguish between these models with high accuracy for a supernova at a distance of up to 100 kpc. Once the next galactic supernova happens, this ability will be a powerful tool for guiding simulations towards a precise reproduction of the explosion mechanism observed in nature.
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Submitted 20 July, 2021; v1 submitted 13 January, 2021;
originally announced January 2021.
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The Hyper-Kamiokande Experiment -- Snowmass LOI
Authors:
Hyper-Kamiokande Collaboration,
:,
K. Abe,
P. Adrich,
H. Aihara,
R. Akutsu,
I. Alekseev,
A. Ali,
F. Ameli,
L. H. V. Anthony,
A. Araya,
Y. Asaoka,
V. Aushev,
I. Bandac,
M. Barbi,
G. Barr,
M. Batkiewicz-Kwasniak,
M. Bellato,
V. Berardi,
L. Bernard,
E. Bernardini,
L. Berns,
S. Bhadra,
J. Bian,
A. Blanchet
, et al. (366 additional authors not shown)
Abstract:
Hyper-Kamiokande is the next generation underground water Cherenkov detector that builds on the highly successful Super-Kamiokande experiment. The detector which has an 8.4~times larger effective volume than its predecessor will be located along the T2K neutrino beamline and utilize an upgraded J-PARC beam with 2.6~times beam power. Hyper-K's low energy threshold combined with the very large fiduc…
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Hyper-Kamiokande is the next generation underground water Cherenkov detector that builds on the highly successful Super-Kamiokande experiment. The detector which has an 8.4~times larger effective volume than its predecessor will be located along the T2K neutrino beamline and utilize an upgraded J-PARC beam with 2.6~times beam power. Hyper-K's low energy threshold combined with the very large fiducial volume make the detector unique, that is expected to acquire an unprecedented exposure of 3.8~Mton$\cdot$year over a period of 20~years of operation. Hyper-Kamiokande combines an extremely diverse science program including nucleon decays, long-baseline neutrino oscillations, atmospheric neutrinos, and neutrinos from astrophysical origins. The scientific scope of this program is highly complementary to liquid-argon detectors for example in sensitivity to nucleon decay channels or supernova detection modes. Hyper-Kamiokande construction has started in early 2020 and the experiment is expected to start operations in 2027. The Hyper-Kamiokande collaboration is presently being formed amongst groups from 19 countries including the United States, whose community has a long history of making significant contributions to the neutrino physics program in Japan. US physicists have played leading roles in the Kamiokande, Super-Kamiokande, EGADS, K2K, and T2K programs.
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Submitted 1 September, 2020;
originally announced September 2020.
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Study of space charge in the ICARUS T600 detector
Authors:
M. Antonello,
B. Baibussinov,
V. Bellini,
F. Boffelli,
M. Bonesini,
A. Bubak,
S. Centro,
K. Cieslik,
A. G. Cocco,
A. Dabrowska,
A. Dermenev,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk,
J. Holeczek,
M. Kirsanov,
J. Kisiel,
I. Kochanek,
J. Lagoda,
A. Menegolli
, et al. (23 additional authors not shown)
Abstract:
The accumulation of positive ions, produced by ionizing particles crossing Liquid Argon Time Projection Chambers (LAr-TPCs), may generate distortions of the electric drift field affecting the track reconstruction of the ionizing events. These effects could become relevant for large LAr-TPCs operating at surface or at shallow depth, where the detectors are exposed to a copious flux of cosmic rays.…
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The accumulation of positive ions, produced by ionizing particles crossing Liquid Argon Time Projection Chambers (LAr-TPCs), may generate distortions of the electric drift field affecting the track reconstruction of the ionizing events. These effects could become relevant for large LAr-TPCs operating at surface or at shallow depth, where the detectors are exposed to a copious flux of cosmic rays. A detailed study of such possible field distortions in the ICARUS T600 LAr-TPC has been performed analyzing a sample of cosmic muon tracks recorded with one T600 module operated at surface in 2001. The maximum track distortion turns out to be of few mm in good agreement with the prediction by a numerical calculation. As a cross-check, the same analysis has been performed on a cosmic muon sample recorded during the ICARUS T600 run at the LNGS underground laboratory, where the cosmic ray flux was suppressed by a factor $\sim 10^6$ by 3400 m water equivalent shielding. No appreciable distortion has been observed, confirming that the effects measured on surface are actually due to ion space charge.
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Submitted 28 May, 2020; v1 submitted 24 January, 2020;
originally announced January 2020.
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Muon momentum measurement in ICARUS-T600 LAr-TPC via multiple scattering in few-GeV range
Authors:
Maddalena Antonello,
Bagdat Baibussinov,
Vincenzo Bellini,
Pietro Angelo Benetti,
Fabrizio Boffelli,
Arkadiusz Bubak,
Elio Calligarich,
Sandro Centro,
Tommaso Cervi,
Alessandra Cesana,
Krzysztof Cieslik,
Alfredo G. Cocco,
Anna Dabrowska,
Alexander Dermenev,
Andrea Falcone,
Christian Farnese,
Angela Fava,
Alfredo Ferrari,
Daniele Gibin,
Sergei Gninenko,
Alberto Guglielmi,
Malgorzata Haranczyk,
Jacek Holeczek,
Michal Janik,
Mikhail Kirsanov
, et al. (32 additional authors not shown)
Abstract:
The measurement of muon momentum by Multiple Coulomb Scattering is a crucial ingredient to the reconstruction of νμ CC events in the ICARUS-T600 liquid argon TPC in absence of magnetic field, as in the search for sterile neutrinos at Fermilab where ICARUS will be exposed to ~1 GeV Booster neutrino beam. A sample of ~1000 stopping muons produced by charged current interactions of CNGS νμ in the sur…
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The measurement of muon momentum by Multiple Coulomb Scattering is a crucial ingredient to the reconstruction of νμ CC events in the ICARUS-T600 liquid argon TPC in absence of magnetic field, as in the search for sterile neutrinos at Fermilab where ICARUS will be exposed to ~1 GeV Booster neutrino beam. A sample of ~1000 stopping muons produced by charged current interactions of CNGS νμ in the surrounding rock at the INFN Gran Sasso underground Laboratory provides an ideal benchmark in the few-GeV range since their momentum can be directly and independently obtained by the calorimetric measurement. Stopping muon momentum in the 0.5- 4.5 GeV/c range has been reconstructed via Multiple Coulomb Scattering with resolution ranging from 10 to 25 % depending on muon energy, track length and uniformity of the electric field in the drift volume.
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Submitted 28 February, 2017; v1 submitted 22 December, 2016;
originally announced December 2016.
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Operation and performance of the ICARUS-T600 cryogenic plant at Gran Sasso underground Laboratory
Authors:
M. Antonello,
P. Aprili,
B. Baibussinov,
F. Boffelli,
A. Bubak,
E. Calligarich,
N. Canci,
S. Centro,
A. Cesana,
K. Cieślik,
D. B. Cline,
A. G. Cocco,
A. Dabrowski,
A. Dermenev,
J. M. Disdier,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk,
J. Holeczek,
A. Ivashkin
, et al. (33 additional authors not shown)
Abstract:
ICARUS T600 liquid argon time projection chamber is the first large mass electronic detector of a new generation able to combine the imaging capabilities of the old bubble chambers with the excellent calorimetric energy measurement. After the three months demonstration run on surface in Pavia during 2001, the T600 cryogenic plant was significantly revised, in terms of reliability and safety, in vi…
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ICARUS T600 liquid argon time projection chamber is the first large mass electronic detector of a new generation able to combine the imaging capabilities of the old bubble chambers with the excellent calorimetric energy measurement. After the three months demonstration run on surface in Pavia during 2001, the T600 cryogenic plant was significantly revised, in terms of reliability and safety, in view of its long-term operation in an underground environment. The T600 detector was activated in Hall B of the INFN Gran Sasso Laboratory during Spring 2010, where it was operated without interruption for about three years, taking data exposed to the CERN to Gran Sasso long baseline neutrino beam and cosmic rays. In this paper the T600 cryogenic plant is described in detail together with the commissioning procedures that lead to the successful operation of the detector shortly after the end of the filling with liquid Argon. Overall plant performance and stability during the long-term underground operation are discussed. Finally, the decommissioning procedures, carried out about six months after the end of the CNGS neutrino beam operation, are reported.
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Submitted 22 April, 2015; v1 submitted 7 April, 2015;
originally announced April 2015.
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Some conclusive considerations on the comparison of the ICARUS nu_mu to nu_e oscillation search with the MiniBooNE low-energy event excess
Authors:
M. Antonello,
B. Baibussinov,
P. Benetti,
F. Boffelli,
A. Bubak,
E. Calligarich,
S. Centro,
A. Cesana,
K. Cieslik,
D. B. Cline,
A. G. Cocco,
A. Dabrowska,
A. Dermenev,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk,
J. Holeczek,
M. Kirsanov,
J. Kisiel,
I. Kochanek
, et al. (29 additional authors not shown)
Abstract:
A sensitive search for anomalous LSND-like nu_mu to nu_e oscillations has been performed by the ICARUS Collaboration exposing the T600 LAr-TPC to the CERN to Gran Sasso (CNGS) neutrino beam. The result is compatible with the absence of additional anomalous contributions giving a limit to oscillation probability of 3.4E-3 and 7.6E-3 at 90% and 99% confidence levels respectively showing a tension be…
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A sensitive search for anomalous LSND-like nu_mu to nu_e oscillations has been performed by the ICARUS Collaboration exposing the T600 LAr-TPC to the CERN to Gran Sasso (CNGS) neutrino beam. The result is compatible with the absence of additional anomalous contributions giving a limit to oscillation probability of 3.4E-3 and 7.6E-3 at 90% and 99% confidence levels respectively showing a tension between these new limits and the low-energy event excess (200 < E_nu QE < 475 MeV) reported by MiniBooNE Collaboration. A more detailed comparison of the ICARUS data with the MiniBooNE low-energy excess has been performed, including the energy resolution as obtained from the official MiniBooNE data release. As a result the previously reported tension is confirmed at 90% C.L., suggesting an unexplained nature or an otherwise instrumental effect for the MiniBooNE low energy event excess
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Submitted 17 February, 2015;
originally announced February 2015.
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Experimental observation of an extremely high electron lifetime with the ICARUS-T600 LAr-TPC
Authors:
M. Antonello,
B. Baibussinov,
P. Benetti,
F. Boffelli,
A. Bubak,
E. Calligarich,
S. Centro,
A. Cesana,
K. Cieslik,
D. B. Cline,
A. G. Cocco,
A. Dabrowska,
A. Dermenev,
R. Dolfini,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
G. Fiorillo,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk,
J. Holeczek,
M. Kirsanov
, et al. (32 additional authors not shown)
Abstract:
The ICARUS T600 detector, the largest liquid Argon Time Projection Chamber (LAr-TPC) realized after many years of RD activities, was installed and successfully operated for 3 years at the INFN Gran Sasso underground Laboratory. One of the most important issues was the need of an extremely low residual electronegative impurity content in the liquid Argon, in order to transport the free electrons cr…
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The ICARUS T600 detector, the largest liquid Argon Time Projection Chamber (LAr-TPC) realized after many years of RD activities, was installed and successfully operated for 3 years at the INFN Gran Sasso underground Laboratory. One of the most important issues was the need of an extremely low residual electronegative impurity content in the liquid Argon, in order to transport the free electrons created by the ionizing particles with a very small attenuation along the drift path. The solutions adopted for the Argon re-circulation and purification systems have permitted to reach impressive results in terms of Argon purity and a free electron lifetime exceeding 15 ms, corresponding to about 20 parts per trillion of equivalent O2 contamination, a milestone for any future project involving LAr-TPC's and the development of higher detector mass scales.
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Submitted 12 January, 2015; v1 submitted 19 September, 2014;
originally announced September 2014.
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The trigger system of the ICARUS experiment for the CNGS beam
Authors:
M. Antonello,
B. Baibussinov,
P. Benetti,
F. Boffelli,
A. Bubak,
E. Calligarich,
S. Centro,
A. Cesana,
K. Cieslik,
D. B. Cline,
A. G. Cocco,
A. Dabrowska,
D. Dequal,
A. Dermenev,
R. Dolfini,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
G. Fiorillo,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk,
J. Holeczek
, et al. (34 additional authors not shown)
Abstract:
The ICARUS T600 detector, with its 470 tons of active mass, is the largest liquid Argon TPC ever built. Operated for three years in the LNGS underground laboratory, it has collected thousands of CNGS neutrino beam interactions and cosmic ray events with energy spanning from tens of MeV to tens of GeV, with a trigger system based on scintillation light, charge signal on TPC wires and time informati…
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The ICARUS T600 detector, with its 470 tons of active mass, is the largest liquid Argon TPC ever built. Operated for three years in the LNGS underground laboratory, it has collected thousands of CNGS neutrino beam interactions and cosmic ray events with energy spanning from tens of MeV to tens of GeV, with a trigger system based on scintillation light, charge signal on TPC wires and time information (for beam related events only). The performance of trigger system in terms of efficiency, background and live-time as a function of the event energy for the CNGS data taking is presented.
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Submitted 8 August, 2014; v1 submitted 29 May, 2014;
originally announced May 2014.
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Search for anomalies in the νe appearance from a νμ beam
Authors:
M. Antonello,
B. Baibussinov,
P. Benetti,
F. Boffelli,
A. Bubak,
E. Calligarich,
N. Canci,
S. Centro,
A. Cesana,
K. Cieslik,
D. B. Cline,
A. G. Cocco,
A. Dabrowska,
D. Dequal,
A. Dermenev,
R. Dolfini,
A. Falcone,
C. Farnese,
A. Fava,
A. Ferrari,
G. Fiorillo,
D. Gibin,
S. Gninenko,
A. Guglielmi,
M. Haranczyk
, et al. (35 additional authors not shown)
Abstract:
We report an updated result from the ICARUS experiment on the search for νμ ->νe anomalies with the CNGS beam, produced at CERN with an average energy of 20 GeV and travelling 730 km to the Gran Sasso Laboratory. The present analysis is based on a total sample of 1995 events of CNGS neutrino interactions, which corresponds to an almost doubled sample with respect to the previously published result…
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We report an updated result from the ICARUS experiment on the search for νμ ->νe anomalies with the CNGS beam, produced at CERN with an average energy of 20 GeV and travelling 730 km to the Gran Sasso Laboratory. The present analysis is based on a total sample of 1995 events of CNGS neutrino interactions, which corresponds to an almost doubled sample with respect to the previously published result. Four clear νe events have been visually identified over the full sample, compared with an expectation of 6.4 +- 0.9 events from conventional sources. The result is compatible with the absence of additional anomalous contributions. At 90% and 99% confidence levels the limits to possible oscillated events are 3.7 and 8.3 respectively. The corresponding limit to oscillation probability becomes consequently 3.4 x 10-3 and 7.6 x 10-3 respectively. The present result confirms, with an improved sensitivity, the early result already published by the ICARUS collaboration.
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Submitted 7 August, 2013; v1 submitted 17 July, 2013;
originally announced July 2013.
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Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
Authors:
The PANDA Collaboration,
W. Erni,
I. Keshelashvili,
B. Krusche,
M. Steinacher,
Y. Heng,
Z. Liu,
H. Liu,
X. Shen,
O. Wang,
H. Xu,
J. Becker,
F. Feldbauer,
F. -H. Heinsius,
T. Held,
H. Koch,
B. Kopf,
M. Pelizaeus,
T. Schroeder,
M. Steinke,
U. Wiedner,
J. Zhong,
A. Bianconi,
M. Bragadireanu,
D. Pantea
, et al. (387 additional authors not shown)
Abstract:
This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.
This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.
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Submitted 1 July, 2009;
originally announced July 2009.
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Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)
Authors:
PANDA Collaboration,
W. Erni,
I. Keshelashvili,
B. Krusche,
M. Steinacher,
Y. Heng,
Z. Liu,
H. Liu,
X. Shen,
O. Wang,
H. Xu,
J. Becker,
F. Feldbauer,
F. -H. Heinsius,
T. Held,
H. Koch,
B. Kopf,
M. Pelizaeus,
T. Schroeder,
M. Steinke,
U. Wiedner,
J. Zhong,
A. Bianconi,
M. Bragadireanu,
D. Pantea
, et al. (387 additional authors not shown)
Abstract:
This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment, which is being developed for the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. The performance figures are based on extensive prototype tests and…
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This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment, which is being developed for the Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface.
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Submitted 7 October, 2008;
originally announced October 2008.