Among other detectors, the T2K neutrino experiment comprises three large time projection chambers segmented into over 124.000 electronics channels. The back-end electronics system is designed to ...distribute a reference clock to the front-end electronics, aggregate event data over seventy-two 2 Gbit/s optical links and format events that are sent via a standard PC to the global data acquisition system of the experiment. The core of this system is a set of 18 Data Concentrator Cards based on an inexpensive commercial Field Programmable Gate Array evaluation kit with specific add-ons. We describe the adaptations that were made to the original platform, and detail the design of the firmware and software running on the embedded PowerPC processor of the FPGA of a Data Concentrator Card. We show how the intrinsic parallelism and a mixed firmware and software implementation of the data reduction and acquisition tasks lead to a flexible system capable of extracting in real time meaningful information from the 2.5 GByte/s of raw event data produced by the front-end electronics at a nominal rate of 20 Hz.
The T2K Fine Grained Detector (FGD) is an active neutrino target that uses segmented scintillator bars to observe short-range particle tracks. 8448 multipixel photon counters (MPPCs) coupled to ...wavelength shifting fibres detect scintillator light. An application specific integrated circuit (ASIC) shapes the MPPC waveform and uses a switched capacitor array (SCA) to store up to 511 analog samples over 10.22 μs. High and low attenuation channels for each MPPC improve dynamic range. 12-bit serial quad-ADCs digitize ASIC analog output and interface with a field programmable gate array (FPGA). Each FPGA simultaneously reads out four ADCs and saves the synchronized samples in an external digital memory. The system produces 13.5 MB of uncompressed data with a target trigger rate of 20 Hz, and requires zero suppression to reduce data size and readout time. Firmware based data compression uses an online pulse-finder that decides whether to output pulse height information, a section of waveform, or to suppress all data. The front end FPGA transfers formatted data to data concentrator cards (DCCs) through a 2 Gb/s optical fiber interface using an efficient custom protocol. We have evaluated the performance of the FGD electronics system and the quality of its online data compression through the course of a physics data run. The average size of a compressed data acquisition is measured as 44 ~ kB.
The T2K fine-grained detectors Amaudruz, P.-A.; Barbi, M.; Bishop, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2012, Letnik:
696
Journal Article
Recenzirano
Odprti dostop
T2K is a long-baseline neutrino oscillation experiment searching for νe appearance in a νμ beam. The beam is produced at the J-PARC accelerator complex in Tokai, Japan, and the neutrinos are detected ...by the Super-Kamiokande detector located 295km away in Kamioka. A suite of near detectors (ND280) located 280 m downstream of the production target is used to characterize the components of the beam before they have had a chance to oscillate and to better understand various neutrino interactions on several nuclei. This paper describes the design and construction of two massive fine-grained detectors (FGDs) that serve as active targets in the ND280 tracker. One FGD is composed solely of scintillator bars while the other is partly scintillator and partly water. Each element of the FGDs is described, including the wavelength shifting fiber and Multi-Pixel Photon Counter used to collect the light signals, the readout electronics, and the calibration system. Initial tests and in situ results of the FGDs' performance are also presented.
A remote control system has been developed for versa module Eurocard (VME) modules located in a radiation environment. Two new VME modules-the remote controller (RC) and local interface modules-are ...introduced to mediate between the local host and remote slave modules. These two modules are connected with optical links and the local host can master the remote VME bus to access the slave modules through these intermediate modules. This control system can perform watchdog for field programmable gate array (FPGA)-embedded modules whose configuration data are susceptible to single event upsets (SEUs). The architectural study and first prototyping of this system are discussed.
A slice test system has been constructed for the ATLAS end-cap muon level-1 trigger. ATLAS is one of the four Large Hadron Collider (LHC) experiment. Although the system has been constructed using ...prototype application specific integrated circuits (ASICs) and electronics modules, the design scheme of the trigger, readout as well as control logic applied to the system is the final one. The size is about 1/300 of the whole number of channels. The purpose of the slice test is to demonstrate the system design and performance in detail prior to production commitment. In this paper, we discuss the validity of the logic through the comparison of the simulation results, the latency measurement and long run tests.
A tool kit for object-oriented network-distributed online-environment (KONOE), a toolkit for data-acquisition software that is based on object-oriented methodology and network-distributed ...architecture, has been developed. KONOE provides a framework for distributed data-acquisition (DAQ) systems. A distributed DAQ has good scalability because the DAQ user can add inexpensive and high-performance PCs to the system. We have developed a network-distributed DAQ for the KEK PS-T473 Experiment by using the KONOE toolkit, and it is confirmed to have sufficiently good performance to satisfy the requirements from the experiment.
Search for heavy neutrinos in K + → μ + ν H decays Artamonov, A. V.; Bassalleck, B.; Bhuyan, B. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
03/2015, Letnik:
91, Številka:
5
Journal Article
Odprti dostop
Here, evidence of a heavy neutrino, νH, in the K+→μ+νH decays was sought using the E949 experimental data with an exposure of 1.70 × 1012 stopped kaons. With the major background from the radiative ...K+→μ+νμγ decay understood and suppressed, upper limits (90% C.L.) on the neutrino mixing matrix element between the muon and heavy neutrinos, |UμH|2, were set at the level of 10–7 to 10–9 for the heavy neutrino mass region 175 to 300 MeV/c2.
Quenching effects in nitrogen gas scintillation Morii, Hideki; Mizouchi, Kentaro; Nomura, Tadashi ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2004, Letnik:
526, Številka:
3
Journal Article
Recenzirano
We report on the studies of quenching effects in N
2 scintillation. Our main interest is to find a practical gas that reduces the scintillation yield in air substantially. We have studied O
2, CO
2, ...and CH
4 in N
2, and have determined their Stern–Volmer constant. When two quenching gases are used in a mixture, the effects are found to be additive. The quenching mechanism of these gases is discussed and its practical application is reported.
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