The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will explore the phase diagram of strongly interacting matter at high baryon ...density and moderate temperatures in A+A collisions. The energy spectrum will start at 2 AGeV/c and extend up to 11 AGeV/c for the heaviest nuclei at the SIS 100 accelerator set-up. To explore the physics program of CBM, a RICH detector will be employed for electron identification and pion suppression in a momentum range up to 8 GeV/c. Mirror alignment is a key issue for a proper detector operation. The final conceptual design for a monitoring system of the alignment of the mirrors of the CBM RICH detector will be introduced. It consists of a fast qualitative check of the alignment as well as two different methods to derive quantitative numbers for misalignments. A software correction cycle had been developed which, once applied allows to get back to physics performances as in an ideally aligned case.
•A hardware-based method used to quantify mirror rotations is presented.•Errors up to 2.75% of the applied rotation are observed for a vertical rotation.•Errors up to 14.25% of the applied rotation are observed for a diagonal rotation.•A correction cycle correcting ring-track distance with misaligned mirrors is shown.•Software improvements in ring-track matching and electron ID efficiencies are seen.
A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of ...energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air showers the two different hadronic interaction models QGSJet and SIBYLL are used for their generation. The resulting primary energy spectra show that the knee in the all particle spectrum is due to a steepening of the spectra of light elements but, also, that neither of the two simulation sets is able to describe the measured data consistently over the whole energy range with discrepancies appearing in different energy regions.
We report the observation of a steepening in the cosmic ray energy spectrum of heavy primary particles at about 8×10(16) eV. This structure is also seen in the all-particle energy spectrum, but is ...less significant. Whereas the "knee" of the cosmic ray spectrum at 3-5×10(15) eV was assigned to light primary masses by the KASCADE experiment, the new structure found by the KASCADE-Grande experiment is caused by heavy primaries. The result is obtained by independent measurements of the charged particle and muon components of the secondary particles of extensive air showers in the primary energy range of 10(16) to 10(18) eV. The data are analyzed on a single-event basis taking into account also the correlation of the two observables.
► All-particle energy spectrum of cosmic rays between knee and ankle is not a single power law. ► Just above 1016eV the spectrum exhibits a hardening. ► Around 8×1016eV there is a knee-like feature ...in the spectrum.
The energy spectrum of cosmic rays between 1016eV and 1018eV, derived from measurements of the shower size (total number of charged particles) and the total muon number of extensive air showers by the KASCADE-Grande experiment, is described. The resulting all-particle energy spectrum exhibits strong hints for a hardening of the spectrum at approximately 2·1016eV and a significant steepening at ≈8·1016eV. These observations challenge the view that the spectrum is a single power law between knee and ankle. Possible scenarios generating such features are discussed in terms of astrophysical processes that may explain the transition region from galactic to extragalactic origin of cosmic rays.
The RICH detector of the CBM experiment Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2017, Volume:
876
Journal Article
Peer reviewed
The CBM-RICH detector is designed to identify electrons with momenta up to 8GeV/c and high purity as this is essential for the CBM physics program. The detector consist of a CO2-gaseous radiator, a ...spherical mirror system, and Multi-Anode PhotoMultiplier Tubes (MAPMT) of type H12700 from Hamamatsu as photon detectors. The detector concept was verified through R&D studies and a laterally scaled prototype. The results were summarized in a TDR, in which open issues were defined concerning the readout electronics, the shielding of the magnetic stray field in the MAPMT region, the radiation hardness of the MAPMT sensors, and the mechanical holding structure of the mirror system. In this article an overview is given on the CBM RICH development with focus on those open issues.
The KASCADE-Grande experiment Apel, W.D.; Arteaga, J.C.; Badea, A.F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2010, Volume:
620, Issue:
2
Journal Article
Peer reviewed
Open access
KASCADE-Grande is the enlargement of the KASCADE extensive air shower detector, realized to expand the cosmic ray studies from the previous 10
14–10
17
eV primary energy range to 10
18
eV. This is ...performed by extending the area covered by the KASCADE electromagnetic array from 200×200 to 700×700
m
2 by means of 37 scintillator detector stations of 10
m
2 area each. This new array is named Grande and provides measurements of the all-charged particle component of extensive air showers (
N
ch
), while the original KASCADE array particularly provides information on the muon content
(
N
μ
)
. Additional dense compact detector set-ups being sensitive to energetic hadrons and muons are used for data consistency checks and calibration purposes. The performance of the Grande array and its integration into the entire experimental complex is discussed. It is demonstrated that the overall observable resolutions are adequate to meet the physical requirements of the measurements, i.e. primary energy spectrum and elemental composition studies in the primary cosmic ray energy range of 10
16–10
18
eV.
The radio technique is a promising method for detection of cosmic-ray air showers of energies around 100PeV and higher with an array of radio antennas. Since the amplitude of the radio signal can be ...measured absolutely and increases with the shower energy, radio measurements can be used to determine the air-shower energy on an absolute scale. We show that calibrated measurements of radio detectors operated in coincidence with host experiments measuring air showers based on other techniques can be used for comparing the energy scales of these host experiments. Using two approaches, first via direct amplitude measurements, and second via comparison of measurements with air shower simulations, we compare the energy scales of the air-shower experiments Tunka-133 and KASCADE-Grande, using their radio extensions, Tunka-Rex and LOPES, respectively. Due to the consistent amplitude calibration for Tunka-Rex and LOPES achieved by using the same reference source, this comparison reaches an accuracy of approximately 10% – limited by some shortcomings of LOPES, which was a prototype experiment for the digital radio technique for air showers. In particular we show that the energy scales of cosmic-ray measurements by the independently calibrated experiments KASCADE-Grande and Tunka-133 are consistent with each other on this level.
Status of the CBM and HADES RICH projects at FAIR Adamczewski-Musch, J.; Akishin, P.; Bendarouach, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2020, Volume:
952
Journal Article
Peer reviewed
The upgraded HADES RICH detector, as well as the future CBM RICH detector, will both use the same Hamamatsu H12700 Multianode PMTs read out by the newly developed DiRICH FPGA-TDC readout chain for ...MAPMTs and MCPs. The upgrade of the HADES RICH photon detector has meanwhile been completed, and we are now looking forward to the upcoming physics run in spring 2019. A brief overview on the status of both detector projects is given and supplemented with the recent test-beam results which confirmed the functionality of the DiRICH development before the start of the mass-production of all DiRICH components needed for the HADES RICH upgrade.
Calibration and characterization of the IceCube photomultiplier tube Abdou, Y.; Baker, M.; Bay, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2010, Volume:
618, Issue:
1
Journal Article
Peer reviewed
Open access
Over 5000 PMTs are being deployed at the South Pole to compose the IceCube neutrino observatory. Many are placed deep in the ice to detect Cherenkov light emitted by the products of high-energy ...neutrino interactions, and others are frozen into tanks on the surface to detect particles from atmospheric cosmic ray showers. IceCube is using the 10-in. diameter R7081-02 made by Hamamatsu Photonics. This paper describes the laboratory characterization and calibration of these PMTs before deployment. PMTs were illuminated with pulses ranging from single photons to saturation level. Parameterizations are given for the single photoelectron charge spectrum and the saturation behavior. Time resolution, late pulses and afterpulses are characterized. Because the PMTs are relatively large, the cathode sensitivity uniformity was measured. The absolute photon detection efficiency was calibrated using Rayleigh-scattered photons from a nitrogen laser. Measured characteristics are discussed in the context of their relevance to IceCube event reconstruction and simulation efforts.
Single photon test bench for series tests of HAMAMATSU H12700 MAPMTs Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2017, Volume:
876
Journal Article
Peer reviewed
In 2015 1100 Multi-Anode Photo-Multipliers (MAPMTs) of type HAMAMATSU H12700 were ordered to equip the photon detection plane of the CBM-RICH and HADES-RICH detectors. Both experiments aim to study ...the properties of dense matter produced in heavy ion collisions. To measure the characteristics of all ordered MAPMTs and give feedback to the manufacturer, a test bench was built at the University of Wuppertal. This paper describes the working principle of the test bench and compiles the measurements of the first 400 H12700 MAPMTs delivered. The average characteristics of the H12700 gathered from these measurements are discussed and compared to measurements of the HAMAMATSU H8500.
•Valuable MAPMT characteristics retrievable from single photon test bench.•The HAMAMATSU H12700 is more efficient than the HAMAMATSU H8500 at ∼460nm.•First H12700 shows a gradient in the single photon detection efficiency in X-direction.
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