Abstract
The next generation of muon spin spectrometers at the ISIS pulsed source are being developed to make efficient use of the increased source intensity. They will provide a transformational ...improvement in counting rates: ‘Super-MuSR’ will be the first of these instruments, capable of counting at ≈1 G·event·hr
−1
. Key to delivering this capability is the development of highly pixelated, high density detector arrays that cover an appreciable solid angle, with each detector element optimised for counting at very high data rates. A series of ‘firsts’ are planned to optimise individual element count rate capability, where analogue waveforms recorded from SiPMs are fully digitised and processed using digital signal processing (DSP) methods at either software or firmware level. Full raw-signal digitisation will be achieved using the Xilinx Zynq
®
UltraScale+
TM
series of ‘system on a chip’ operating with ADCs capable of 1 GHz sampling, data handling using event streaming technology, and DSP to provide novel data correction techniques. We will discuss our concept and present preliminary results. Our prototype digitising data acquisition system, which is key to implementing a ‘digital data pipeline’ (DDP) is presented.
Charged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on ...350μm diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented.
The liquid-hydrogen absorber for MICE Bayliss, V; Boehm, J; Bradshaw, T ...
IOP conference series. Materials Science and Engineering,
04/2019, Letnik:
502, Številka:
1
Journal Article
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This paper describes the liquid hydrogen system constructed for The Muon Ionization Cooling Experiment (MICE); MICE was built at the STFC Rutherford Appleton Laboratory to demonstrate the principle ...of muon beam phase-space reduction via ionization cooling. Muon beam cooling will be required at a future proton-derived neutrino factory or muon collider. Ionization cooling is achieved by passing the beam through an energy-absorbing material, such as liquid hydrogen, and then re-accelerating the beam using RF cavities. This paper describes the system creating the 22l of liquid hydrogen within the MICE beamline; the necessary safety engineering, the liquid hydrogen absorber and its associated cryogenic and gas systems are presented, along with its performance.
The off-detector part of the optical links for the ATLAS SCT and Pixel detectors is described. The VCSELs and p–i–n diodes used and the associated ASICs are described. A novel array packaging ...technique is explained and an analysis of the performance of the arrays and the overall system performance is given. The proposed procedure for the set-up of the optical links in ATLAS is described.
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, ...whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2-2.3 π mm-rad horizontally and 0.6-1.0 π mm-rad vertically, a horizontal dispersion of 90-190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.
Super-MuSR is the first of the next generation of muon spin spectrometers and is currently being built at the ISIS pulsed source, UK. Funded via the 'Endeavour Programme', Super-MuSR is a six million ...pound development which will provide novel muon techniques at transformational counting rates. The expected counting rate is an order of magnitude greater than the existing instrument, exceeding 10^ 9 *counts*hr -1 . The improved count rate capability comes from the use of silicon photomultipliers (SiPM) to build a high density detector array and the implementation of a new digital signal processing pipeline. The array will exceed 700 independent detector channels in a barrel geometry, roughly 1 m in length and 0.35 m in diameter. Each SiPM is coupled to a plastic scintillator using wavelength shifting fibers. Encapsulation of the 'tile' assembly is required for light collection and optical isolation from the environment. Comparison of encapsulation methods, including spray-coatings are reported. Signal digitisation, processing and streaming are provided by Nuclear Instruments DAQ 121, which uses a Xilinx Zynq ® UltraScale +TM 'system on a chip' with ADCs capable of 1 GHz sampling. Super-MuSR's count-rate stability specification, a 0.032% variation, translate into a demanding thermal stability requirement. To hold the array at a fixed temperature a novel temperature control system has been developed. A resistive heater has been embedded inside the readout PCB in a 'serpentine' pattern, capable of delivering 400 mW of power, heating the SiPM to ≈45 °C.
Accelerated muon beams have been considered for next-generation studies of high-energy lepton-antilepton collisions and neutrino oscillations. However, high-brightness muon beams have not yet been ...produced. The main challenge for muon acceleration and storage stems from the large phase-space volume occupied by the beam, derived from the muon production mechanism through the decay of pions from proton collisions. Ionization cooling is the technique proposed to decrease the muon beam phase-space volume. Here we demonstrate a clear signal of ionization cooling through the observation of transverse emittance reduction in beams that traverse lithium hydride or liquid hydrogen absorbers in the Muon Ionization Cooling Experiment (MICE). The measurement is well reproduced by the simulation of the experiment and the theoretical model. The results shown here represent a substantial advance towards the realization of muon-based facilities that could operate at the energy and intensity frontiers.
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