211 research outputs found
Performance of the most recent Microchannel-Plate PMTs for the PANDA DIRC detectors at FAIR
In the PANDA experiment at the FAIR facility at GSI two DIRC (Detection of
Internally Reflected Cherenkov light) detectors will be used for /K
separation up to 4 GeV/c. Due to their location in a high magnetic field and
other stringent requirements like high detection efficiency, low dark count
rate, radiation hardness, long lifetime and good timing, MCP-PMTs
(microchannel-plate photomultiplier) were the best choice of photon sensors for
the DIRC detectors in the PANDA experiment. This paper will present the
performance of some of the latest 22 inch MCP-PMTs from Photek and
Photonis, including the first mass production tubes for the PANDA Barrel DIRC
from Photonis. Performance parameters like the collection efficiency (CE),
quantum efficiency (QE), and gain homogeneity were determined. The effect of
magnetic fields on some properties like gain and charge cloud width was
investigated as well. Apart from that the spatial distribution of many internal
parameters like time resolution, dark count rate, afterpulse ratio, charge
sharing crosstalk and recoil electrons were measured simultaneously with a
multihit capable DAQ system. The latest generation of Photonis MCP-PMTs shows
an unexpected "escalation" effect where the MCP-PMT itself produces photons.Comment: Proceedings contribution to RICH2022 (11th International Workshop on
Ring Imaging Cherenkov Detectors
Lifetime and performance of the very latest microchannel-plate photomultipliers
The PANDA experiment at the FAIR facility at GSI will study hadron physics
using a high intensity antiproton beam of up to 15 GeV/c momentum to perform
high precision spectroscopy. Two DIRC detectors with their image planes
residing in an 1 T magnetic field will be used in the experiment. The
only suitable photon detectors for both DIRCs were identified to be
Microchannel-Plate Photomultipliers (MCP-PMTs). Since the aging problems of
MCP-PMTs were solved recently by coating the MCPs with the so-called
ALD-technique (atomic layer deposition) we are investigating devices which are
significantly improved with respect to other parameters, as, e.g., the
collection efficiency (CE) and the quantum efficiency (QE). The latest
generation of MCP-PMTs can reach a detective quantum efficiency DQE = QE - CE
of 30%. This paper will present the performance of the most advanced 53
53 mm ALD-coated MCP-PMTs from Photonis (8 8 and 3
100 anodes) and Photek (8 8 anodes), also inside the magnetic
field. With a picosecond laser and a multi-hit capable DAQ system which allows
read out up to 300 pixels simultaneously, parameters like darkcount rate,
afterpulse probability and time resolution can be investigated as a function of
incident photon position.Comment: Proceedings contribution to NDIP20 (9th Conference on New
Developments in Photodetection
KM3NeT front-end and readout electronics system: hardware, firmware, and software
[EN] The KM3NeT research infrastructure being built at the bottom of the Mediterranean Sea will host
water-Cherenkov telescopes for the detection of cosmic neutrinos. The neutrino telescopes will consist of large
volume three-dimensional grids of optical modules to detect the Cherenkov light from charged particles produced
by neutrino-induced interactions. Each optical module houses 31 3-in. photomultiplier tubes, instrumentation for
calibration of the photomultiplier signal and positioning of the optical module, and all associated electronics
boards. By design, the total electrical power consumption of an optical module has been capped at seven
Watts. We present an overview of the front-end and readout electronics system inside the optical module, which
has been designed for a 1-ns synchronization between the clocks of all optical modules in the grid during a life
time of at least 20 years.The authors acknowledge financial support from the funding agencies: Agence Nationale de la Recherche (Grant No. ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (Grant Nos. ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, Grant No. FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education, Scientific Research and Professional Training, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Plan Estatal de Investigacion [refs. FPA2015-65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)], Severo Ochoa Centre of Excellence program (MINECO), Red Consolider MultiDark (ref. FPA2017-90566-REDC, MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), "la Caixa" Foundation (ID 100010434) through the fellowship LCF/BQ/IN17/11620019, and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 713673, Spain.Aiello, S.; Ameli, F.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.... (2019). KM3NeT front-end and readout electronics system: hardware, firmware, and software. Journal of Astronomical Telescopes, Instruments, and Systems. 5(4):1-15. https://doi.org/10.1117/1.JATIS.5.4.046001S1155
Testing Lorentz Invariance and CPT Conservation with NuMI Neutrinos in the MINOS Near Detector
A search for a sidereal modulation in the MINOS near detector neutrino data
was performed. If present, this signature could be a consequence of Lorentz and
CPT violation as predicted by a class of extensions to the Standard Model. No
evidence for a sidereal signal in the data set was found, implying that there
is no significant change in neutrino propagation that depends on the direction
of the neutrino beam in a sun-centered inertial frame. Upper limits on the
magnitudes of the Lorentz and CPT violating terms in these extensions to the
Standard Model lie between 0.01-1% of the maximum expected, assuming a
suppression of these signatures by factor of .
A Study of Muon Neutrino Disappearance Using the Fermilab Main Injector Neutrino Beam
We report the results of a search for muon-neutrino disappearance by the Main
Injector Neutrino Oscillation Search. The experiment uses two detectors
separated by 734 km to observe a beam of neutrinos created by the Neutrinos at
the Main Injector facility at Fermi National Accelerator Laboratory. The data
were collected in the first 282 days of beam operations and correspond to an
exposure of 1.27e20 protons on target. Based on measurements in the Near
Detector, in the absence of neutrino oscillations we expected 336 +/- 14
muon-neutrino charged-current interactions at the Far Detector but observed
215. This deficit of events corresponds to a significance of 5.2 standard
deviations. The deficit is energy dependent and is consistent with two-flavor
neutrino oscillations according to delta m-squared = 2.74e-3 +0.44/-0.26e-3
eV^2 and sin^2(2 theta) > 0.87 at 68% confidence level.Comment: In submission to Phys. Rev.
Measurement of the Atmospheric Muon Charge Ratio at TeV Energies with MINOS
The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray
muon data since the beginning of August, 2003 at a depth of 2070
meters-water-equivalent in the Soudan Underground Laboratory, Minnesota, USA.
The data with both forward and reversed magnetic field running configurations
were combined to minimize systematic errors in the determination of the
underground muon charge ratio. When averaged, two independent analyses find the
charge ratio underground to be 1.374 +/- 0.004 (stat.) +0.012 -0.010(sys.).
Using the map of the Soudan rock overburden, the muon momenta as measured
underground were projected to the corresponding values at the surface in the
energy range 1-7 TeV. Within this range of energies at the surface, the MINOS
data are consistent with the charge ratio being energy independent at the two
standard deviation level. When the MINOS results are compared with measurements
at lower energies, a clear rise in the charge ratio in the energy range 0.3 --
1.0 TeV is apparent. A qualitative model shows that the rise is consistent with
an increasing contribution of kaon decays to the muon charge ratio.Comment: 16 pages, 17 figure
Measurement of neutrino velocity with the MINOS detectors and NuMI neutrino beam
The velocity of a ~3 GeV neutrino beam is measured by comparing detection times at the near and far detectors of the MINOS experiment, separated by 734 km. A total of 473 far detector neutrino events was used to measure (v-c)/c=5.12.910-5 (at 68% C.L.). By correlating the measured energies of 258 charged-current neutrino events to their arrival times at the far detector, a limit is imposed on the neutrino mass of mnu<50 MeV/c2 (99% C.L.)
Feasibility studies of the time-like proton electromagnetic form factor measurements with PANDA at FAIR
The possibility of measuring the proton electromagnetic form factors in the
time-like region at FAIR with the \PANDA detector is discussed. Detailed
simulations on signal efficiency for the annihilation of into a
lepton pair as well as for the most important background channels have been
performed. It is shown that precision measurements of the differential cross
section of the reaction can be obtained in a wide
angular and kinematical range. The individual determination of the moduli of
the electric and magnetic proton form factors will be possible up to a value of
momentum transfer squared of (GeV/c). The total cross section will be measured up to (GeV/c).
The results obtained from simulated events are compared to the existing data.
Sensitivity to the two photons exchange mechanism is also investigated.Comment: 12 pages, 4 tables, 8 figures Revised, added details on simulations,
4 tables, 9 figure
First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector
The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nuµ and [overline nu ]µ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nuµ and [overline nu ]µ interactions are separated. The ratio of [overline nu ]µ to nuµ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nuµ and [overline nu ]µ
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, , is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance
- …