Front-end electronics of the Belle II aerogel ring imaging detector Pestotnik, R.; Adachi, I.; Burmistrov, L. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2020, Letnik:
952
Journal Article
Recenzirano
A proximity focusing RICH detector with an aerogel radiator is used for charged particle identification in the forward end-cap of the Belle II spectrometer. The detector, consisting of a 4 cm aerogel ...radiator, a 16 cm expansion volume and a photon detector with 420 Hybrid Avalanche Photo Detectors, is mounted in a very confined space between Central Drift Chamber and Electromagnetic Calorimeter, allowing only 5 cm of space for the readout electronics. In our solution, low power front-end read-out boards are mounted at the back side of each of the HAPD photosensors. These boards have each been tested individually before their installation onto the photosensors and into the spectrometer. Most important design issues and first experiences with the aforementioned front-end read-out boards are presented in this contribution.
In this paper, experimental observations of spontaneously excited waves in the ion cyclotron range of frequency (ICRF) on JT-60U are described. The fluctuations in ICRF are driven by the presence of ...non-thermal ion distribution in magnetically confined plasmas. Two types of magnetic fluctuations are detected: one is due to high-energy D ions from neutral beam (NB) injections and the other is due to fusion products (FPs) of
3
He and T ions. These fluctuations have been reported as ion cyclotron emissions (ICEs) in the burning plasma experiments on large tokamaks. This paper describes the first measurement of the spatial structures of the excited modes in the poloidal and toroidal directions. It is confirmed by using ICRF antennas as pickup loops that all modes excited spontaneously have magnetic components. The modes due to D ions have zero or a small toroidal wave number
k
z
. On the other hand, the measurement of finite
k
z
in the modes due to FP ions supports the excitation of the Alfvén waves, which is the possible origin of FP-ICEs. It is also observed that the excited modes due to FP ions (
3
He and T ions) have different characteristics: driven by different NBs and having different parameter dependences. ICE due to T ions has no harmonics and the value of ω/Ω
ci
is smaller than that due to
3
He. Both beam-driven ICEs and FP-ICEs are clearly observed and their spatial structures are obtained on JT-60U.
Abstract
The Aerogel Ring Imaging Cherenkov (ARICH) counter serves as a particle identification device in the forward end-cap region of the Belle II spectrometer. It is capable of identifying pions ...and kaons with momenta up to $4\>$GeV$\>$c$^{-1}$ by detecting Cherenkov photons emitted in the silica aerogel radiator. After the detector alignment and calibration of the probability density function, we evaluate the performance of the ARICH counter using early beam collision data. Event samples of $D^{\ast +} \to D^0 \pi^+ (D^0 \to K^-\pi^+)$ were used to determine the $\pi(K)$ efficiency and the $K(\pi)$ misidentification probability. We found that the ARICH counter is capable of separating kaons from pions with an identification efficiency of $93.5 \pm 0.6 \, \%$ at a pion misidentification probability of $10.9 \pm 0.9 \, \%$. This paper describes the identification method of the counter and the evaluation of the performance during its early operation.
Background and purpose:
Despite the rapid progress made in understanding the significant role played by signalling via extracellular ATP in physiology and pathology, there has been no clear ...information generated on its involvement in the emetic response.
Experimental approach:
In the present study, the emetogenic potential of extracellular ATP signalling in mammalian species was examined using ferrets and Suncus murinus (house musk shrews). A slowly degradable ATP analogue, α,β‐methyleneATP (α,β‐meATP), was used to activate the P2X receptors, and either the non‐selective P2 receptor antagonist, pyridoxal phosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS), or the specific P2X3 homomer and P2X2/3 heteromer antagonist, A‐317491, were tested against the agonist‐induced response.
Key results:
Intraperitoneal injection of α,β‐meATP produced significant emetic responses in ferrets (1 ‐ 30 mg kg−1) and in Suncus murinus (5 ‐ 50 mg kg−1). The responses occurred frequently within the first 10 min after administration, much less frequently from 11 to 60 min and no responses occurred later than 60 min. The emetic responses were completely inhibited by intraperitoneal pre‐treatment with PPADS (100 mg kg−1) or A‐317491 (100 mg kg−1). Abdominal surgical vagotomy did not reduce the emetic response in Suncus murinus significantly.
Conclusions and implications:
These results for the first time indicate that the activation of P2X receptors evokes emetic responses in mammalian species. The P2X3 homomer and·or P2X2/3 heteromer in the area postrema could be responsible for the emetic response. This finding contributes to the elucidation of the roles played by extracellular ATP signalling in various emetic symptoms.
British Journal of Pharmacology (2007) 152, 464–470; doi:10.1038/sj.bjp.0707418; published online 13 August 2007
A novel air-stable sodium iron hexacyanoferrate (R-Na1.92FeFe(CN)6) with rhombohedral structure is demonstrated to be a scalable, low-cost cathode material for sodium-ion batteries exhibiting high ...capacity, long cycle life, and good rate capability. The cycling mechanism of the iron redox is clarified and understood through synchrotron-based soft X-ray absorption spectroscopy, which also reveals the correlation between the physical properties and the cell performance of this novel material. More importantly, successful preparation of a dehydrated iron hexacyanoferrate with high sodium-ion concentration enables the fabrication of a discharged sodium-ion battery with a non-sodium metal anode, and the manufacturing feasibility of low cost sodium-ion batteries with existing lithium-ion battery infrastructures has been tested.
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