Aerogel for different types of Cherenkov detectors is produced by a collaboration of Budker Institute of Nuclear Physics and Boreskov Institute of Catalysis during more than two decades. So far only ...the production of two sizes was possible in large numbers: 50 × 50 and 115 × 115mm2. This work is devoted to the development of the production technology of large scale aerogel radiators for use in the Ring-imaging Cherenkov (RICH) detectors. These detectors require additional parameters to be controlled for each aerogel tile during production. Procedures of measurement of the aerogel tiles refractive index, the light scattering length, the upper surface flatness are described.
Operation and performance of the ASHIPH counters at the KEDR detector Barnyakov, A.Yu; Barnyakov, M.Yu; Boborovnikov, V.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
In 2014 the fully installed ASHIPH (Aerogel, SHifter, PHotomultiplier) system began its operation in the KEDR experiment at the VEPP-4M e+e−-collider. The system contains 1000liters of aerogel with ...refractive index n=1.05 in 160 counters that are arranged in two layers. Cherenkov light collection is preformed by means of wavelength shifters (WLS). 160Micro-Channel Plate (MCP) PMTs with multialkali photocathode are used as photodetectors. Efficiency of relativistic particles detection was measured with e+e−→e+e− events and cosmic muons. Detection efficiency for under-threshold particles was measured with cosmic muons. From these data π/K-separation of 4σ at the momentum 1.2GeV/c was obtained.
PID system based on focusing aerogel RICH for the super C-τ factory Barnyakov, A.Yu; Barnyakov, M.Yu; Boborovnikov, V.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2020, Letnik:
952
Journal Article
Recenzirano
A high performance particle identification (PID) system is essential for the successful realization of the broad physics program at the future Super C-τ Factory in Novosibirsk. The main requirements ...for the PID system are as follows: good π/K-separation in the entire operational momentum range and good μ∕π-separation in the momentum range from 0.3 to 1.2 GeV/c. The RICH detector based on focusing aerogel radiator (FARICH) and position-sensitive photon detector meets all these requirements. The FARICH method is described, and the beam test results are presented. The FARICH system design outline for the Super C-τ Factory project is presented. Most promising photon detector options are considered.
We investigate the influence of carbon nanotubes (CNT) aligned array on the magnetic properties of ensemble of densely packed Co nanoparticles (NPs) embedded inside CNT. Each CNT contains only one ...nanosized Co. Such a special structure was formed by catalyst chemical vapor deposition (CCVD) activated by current discharge plasma and hot filament. The Co NPs, previously deposited onto SiO2/Si substrate, acted as a catalyst. By varying the parameters of the CCVD process, we were able to also sputter the substrate instead of CNT growth. Co NPs were used as a mask and the structure of Si-based nanocones with Co NPs on the top of each cone was formed. Exhaustive investigation of the structural, morphology and crystalline properties of Co nanoparticles were performed. The magnetic properties of two kinds of samples, Co on the Si-based nanocone and Co inside CNT, were differ drastically. In the former case, the magnetic anisotropy of thin-film-type has been observed with large magnetic domains. Whereas for the Co-CNT samples ferromagnetic NPs were magnetically isolated. It was established that the magnetic anisotropy of nanosized Co plays more dominant role than the dipole interaction between Co NPs. The role of the CNT container in this is discussed.
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Particle detection efficiency of the KEDR detector ASHIPH system Barnyakov, A.Yu; Barnyakov, M.Yu; Bobrovnikov, V.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2020, Letnik:
952
Journal Article
Recenzirano
The particle identification system ASHIPH (Aerogel, SHifter, PHotomultiplier) has been working in the KEDR experiment at VEPP-4M collider (Budker INP, Novosibirsk) since 2014. The system consists of ...160 counters arranged in two layers and covers the 96% of the solid angle. Two layer system permits to use different approaches for π/K separation. Three such approaches are described. The status of the system is presented. Main system parameters such as BhaBha suppression factor, π/K separation power, relativistic particle detection efficiency were measured with help of cosmic particles and experimental data collected at the peak of J/ψ-meson. π/K separation in the momentum range from 0.95 to 1.45GeV/c is better than 4σ. Monte-Carlo simulation procedures are described and results are presented as well.
The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters ASHIPH (Aerogel, SHifter, PHotomultiplier).The simulation program of the ASHIPH counters was ...developed on the base of the Geant3.21 package and integrated into the KEDR full detector simulation.
In this work, we investigate magnetic properties of iron based nanoparticles (NP) intercalated into carbon nanotube (CNT) aligned arrays synthesized by injection chemical vapor deposition. We have ...analyzed the temperature (T) and the ferrocene concentration (CF) dependences of the macroscopic magnetic parameters. From these experiments a weaker interaction between magnetic moments of NP was obtained for low CF values. The random anisotropy model for the experimental data analysis was applied and micromagnetic parameters were evaluated. The law of the approach to magnetic saturation (LAS) was analyzed using the general expression with the correlation function C(r=x/Ra) of magnetic axes, Ra being the magnetic anisotropy correlation length. We obtained that, while for CF=0.5% C(r) is a step-like (C(r<10)=1, C(r>10)=0), for CF⩾1% C(r) decays rapidly on a short range, (2-3)Ra. Such extended correlations for CF=0.5% could be associated with the dominant role of the coherent anisotropy, which is caused by the influence of the alignment of CNT. When the aligned CNTs for CF=0.5% are destroyed into powder, the LAS is changed to H−1/2, which means the dominant role of the exchange mechanism.
Impact of polishing on the light scattering at aerogel surface Barnyakov, A.Yu; Barnyakov, M.Yu; Bobrovnikov, V.S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
Particle identification power of modern aerogel RICH detectors strongly depends on optical quality of radiators. It was shown that wavelength dependence of aerogel tile transparency after polishing ...cannot be described by the standard Hunt formula. The Hunt formula has been modified to describe scattering in a thin layer of silica dust on the surface of aerogel tile. Several procedures of polishing of aerogel tile have been tested. The best result has been achieved while using natural silk tissue. The resulting block has optical smooth surfaces. The measured decrease of aerogel transparency due to surface scattering is about few percent. This result could be used for production of radiators for the Focusing Aerogel RICH detectors.
Status of aerogel production in Novosibirsk Barnyakov, A.Yu; Barnyakov, M.Yu; Beloborodov, K.I. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
639, Številka:
1
Journal Article
Recenzirano
Silica aerogel blocks are being produced for use in Cherenkov detectors by a collaboration of Boreskov Institute of Catalysis and Budker Institute of Nuclear Physics since 1986. Novosibirsk aerogel ...is used in several detectors; among them are KEDR, SND (BINP, Novosibirsk), LHCb (CERN, Geneva), AMS (for International Space Station mission) and others. Currently our investigations are going on in two directions: multilayer aerogels for Focusing Aerogel RICH and aerogels with high index of refraction. We have synthesized two-, three- and four-layer aerogel tiles with dimensions of 115
mm×115
mm. We have modernized the method of pinhole drying for preparation of aerogels with refractive index in the range of 1.07–1.20.
Focusing Aerogel RICH for particle identification and momentum measurement Barnyakov, A.Yu; Barnyakov, M.Yu; Basok, I.Yu ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Letnik:
639, Številka:
1
Journal Article
Recenzirano
The work is devoted to the development of the Focusing Aerogel RICH (FARICH). The option of the forward RICH for the SuperB project in Italy is presented. It features an aerogel-NaF radiator and MCP ...photodetectors. Monte Carlo simulation predicts the
π
/ K separation at the level better than
3
σ
from 0.2 to 7
GeV/
c, the
μ
/
π
separation—from 0.13 to 1.3
GeV/
c, and the kaon momentum measurement with an accuracy of about 1% at 1
GeV/
c. FARICH for the Super Charm-Tau Factory project in Novosibirsk is proposed. Monte Carlo simulation predicts
μ
/
π
separation at the level better than
3
σ
for a momentum from 0.3 to 1.7
GeV/
c. A prototype will be tested on the new electron test beam facility at VEPP-4M collider.
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