The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) at Darmstadt will be a dedicated heavy-ion experiment for the investigation of baryonic matter ...at highest net-baryon densities. A RICH detector with CO
2 as radiator gas is being developed for clean and efficient electron identification which will be necessary for the measurement of some of the key observables of the physics program of CBM. The status of the development of this RICH detector and results on R&D activities concerning self-triggered readout electronics for PMTs, studies on the usage of wavelength-shifting films, as well as the evaluation of glass mirrors from industrial providers will be presented.
The CBM RICH project Adamczewski-Musch, J.; Becker, K.-H.; Belogurov, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2014, Letnik:
766
Journal Article
Recenzirano
The Compressed Baryonic Matter (CBM) experiment will study the properties of super dense nuclear matter by means of heavy ion collisions at the future FAIR facility. An integral detector component is ...a large Ring Imaging Cherenkov detector with CO sub(2) gas radiator, which will mainly serve for electron identification and pion suppression necessary to access rare dileptonic probes like e super(+)e super(-) decays of light vector mesons or J/ psi psi . We describe the design of this future RICH detector and focus on results obtained by building a CBM RICH detector prototype tested at CERN-PS.
A 64-channel readout and data-acquisition module is described in detail. It consists of an H12700 multianode photomultiplier tube, four PADIWA preamplifier boards, and a TRB v3 card that perform the ...functions of a time-to-digital converter and a data concentrator. The software modules that are necessary for operation of the prototype are described. The inter-channel delays are calibrated. The drift of individual delays does not exceed 0.5 ns for the entire measurement time. The spectra of the “time over threshold” (ToT) are investigated. The influence of periodic noise pickups and the need to improve circuit designs are revealed. The timing properties of the wavelength shifter and its effect on the detection efficiency for Cherenkov rings are investigated. The most intense component is characterized by a decay time of 1.1 ns and there are components with characteristic times of 3.8 and 45 ns. The influence of single-electron spectrum features on the detection efficiency for photoelectrons and the probability of false hits are determined. The total time resolution of 131 channels is 1.1 ns (FWHM). The results make it possible to use the investigated system of readout and data acquisition in the CBM experiment. Nevertheless, the elimination of the revealed shortcomings will provide the efficiency margin and improve the reliability of the system during long-term operation.
Event reconstruction in the RICH detector of the CBM experiment at FAIR Adamczewski, J.; Becker, K.-H.; Belogurov, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2014, Letnik:
766
Journal Article
Recenzirano
The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net-baryon densities and moderate temperatures. One of the key signatures ...will be di-leptons emitted from the hot and dense phase in heavy-ion collisions. Measuring di-electrons, a high purity of identified electrons is required in order to suppress the background. Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). In order to access the foreseen rare probes, the detector and the data acquisition have to handle interaction rates up to 10 MHz. Therefore, the development of fast and efficient event reconstruction algorithms is an important and challenging task in CBM. In this contribution event reconstruction and electron identification algorithms in the RICH detector are presented. So far they have been developed on simulated data but could already be tested on real data from a RICH prototype testbeam experiment at the CERN-PS. Efficient and fast ring recognition algorithms in the CBM-RICH are based on the Hough Transform method. Due to optical distortions of the rings, an ellipse fitting algorithm was elaborated to improve the ring radius resolution. An efficient algorithm based on the Artificial Neural Network was implemented for electron identification in RICH. All algorithms were significantly optimized to achieve maximum speed and minimum memory consumption.
The CBM experiment at the future FAIR facility will explore nuclear matter at high net-baryon densities. One of the key observables is di-leptons as they penetrate the created matter without further ...strong interactions. A gaseous RICH detector in a standard projective geometry using spherical mirrors is one of two detector elements for the required electron identification. The mirror system consists of about 72 trapezoidal mirror tiles. Any misalignment between the tiles relative to the nominal common spherical surface leads to reduction of the reconstruction efficiency of Cherenkov rings and deterioration of their resolution. To determine tolerances in mirror misalignment extensive simulation and measurement studies were carried out. Pure CO sub(2) will be used as radiator gas. Gas contamination, mainly moisture and Oxygen, reduces the number of detected photons per ring and worsens the quality of reconstructed Cherenkov rings. Therefore a study was carried out to determine tolerances in radiator gas contamination.
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, Letnik:
876
Journal Article
Recenzirano
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.
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, Letnik:
876
Journal Article
Recenzirano
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.
Development of the CBM RICH readout electronics and DAQ Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2017, Letnik:
876
Journal Article
Recenzirano
A real size prototype of the CBM RICH detector was tested in beam at CERN in November 2014 with new readout electronics. A detailed analysis of the timing characteristics of the readout chain will be ...presented in this article. Results of the time precision measurements for several subsets of all channels and the stability of the fine time calibration will be discussed. The obtained sub-nanosecond time precision allows also to investigate the effect on timing when using additional wavelength-shifting films on top of the MAPMT windows.
The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) will investigate the phase diagram of strongly interacting matter at high net-baryon ...density and moderate temperature in A+A collisions. One of the key detectors of CBM to explore this physics program is a Ring Imaging CHerenkov (RICH) detector for electron identification. For a high performance of the RICH detector precise mirror alignment is essential. A three-step correction cycle has been developed, which will be discussed: First a qualitative, fast check of the mirror positions, second a quantitative determination of possible misalignments and third a software correction routine, allowing a proper functioning of the RICH under misalignment conditions.
•A monitoring system for the mirror alignment of the CBM RICH detector is presented.•A qualitative inspection checks for misalignments between adjacent mirrors.•A method based on accumulated statistics quantifies the misalignments.•A correction routine allows a proper detector operation in misalignments conditions.
Event reconstruction for the CBM-RICH prototype beamtest data in 2014 Adamczewski-Musch, J.; Akishin, P.; Becker, K.-H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2017, Letnik:
876
Journal Article
Recenzirano
The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net baryon densities and moderate temperatures in A+A collisions from 2 to ...11 AGeV (SIS100). Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD).
A real size prototype of the RICH detector was tested together with other CBM groups at the CERN PS/T9 beam line in 2014. For the first time the data format used the FLESnet protocol from CBM delivering free streaming data. The analysis was fully performed within the CBMROOT framework. In this contribution the data analysis and the event reconstruction methods which were used for obtained data are discussed. Rings were reconstructed using an algorithm based on the Hough Transform method and their parameters were derived with high accuracy by circle and ellipse fitting procedures. We present results of the application of the presented algorithms. In particular we compare results with and without Wavelength shifting (WLS) coating.
•Ring Imaging Cherenkov detector will serve for electron identification in CBM.•A real size prototype of the RICH detector was successfully tested at CERN in 2014.•The analysis was fully performed within the CBMROOT framework.•Ring reconstruction algorithms were successfully tested on real data.•Using a WLS coating increases the detected photon yield by 18%.
