We developed two complementary ways to measure the position of SiPMs inside liquid xenon detector for MEG II experiment; one uses laser tools and the other uses an X-ray beam. We measured the ...position of all SiPMs to an accuracy of 320 μm.
•Precise alignment of SiPMs in liquid xenon detector with X-ray and laser.•The SiPM array is scanned with X-ray beam that makes a local energy deposit.•Reconstructed 3D SiPM array from an image taken by a laser scanner.•Reasonable thermal contraction was observed from the comparison.•Consistent shape of the SiPM array measured by two measurements.
A novel Resistive Plate Chamber (RPC) was designed with Diamond-Like Carbon (DLC) electrodes and performance studies were carried out for 384μm gap configuration with a 2cm×2cm prototype. The use of ...thin films coated with DLC enables an ultra-low mass design of less than 0.1%X0 with up to a four-layer configuration. At the same time, 42% MIP efficiency, and 180ps timing resolution per layer were achieved in a measurement performed under a 1 MHz/cm2 non-MIP charged particle beam. In addition, we propose a further improved design for a 20cm-scale detector that can achieve 90% four-layer efficiency in an even higher 4 MHz/cm2 beam. In this paper, we describe the detector design, present the results of performance measurements, and characterize the rate capability of the DLC-based RPCs with a performance projection for an improved design.
A new type of resistive plate chamber with thin-film electrodes based on diamond-like carbon is under development for background identification in the MEG II experiment. Installed in a low-momentum ...and high-intensity muon beam, the detector is required to have extremely low mass and a high rate capability. A single-layer prototype detector with 2 cm × 2 cm size was constructed and evaluated to have a high rate capability of 1 MHz/cm2 low-momentum muons. For a higher rate capability and scalability of the detector size, the electrodes to supply high voltage were segmented at a 1 cm pitch by implementing a conductive pattern on diamond-like carbon. Using the new electrodes, a four-layer prototype detector was constructed and evaluated to have a 46% detection efficiency with only a single layer active at a rate of O(10 kHz). The result with the new electrodes is promising to achieve the required detection efficiency of 90% at a rate of 4 MHz/cm2 with all the layers active.
A new type of resistive plate chamber (RPC) is under development using thin-film resistive electrodes based on diamond-like carbon (DLC). Planned to be put on the path of high-intensity low-momentum ...muon beam of the MEG II experiment, this detector is required to be high-rate capable and ultra-low mass. Using a prototype detector with 2 cm × 2 cm size and 0.1%
X
0
material budget, performance studies were conducted for MIP detection efficiency, timing resolution and high rate capability in low-momentum muon beam. In this paper, the measured performance is presented including the result with low-momentum muon beam at rate up to 1 MHz/cm
2
. Based on the result, the expected performance of the full-scale detector in the MEG II experiment is also discussed.
The MEG experiment took data at the Paul Scherrer Institute in the years 2009–2013 to test the violation of the lepton flavor conservation law, which originates from an accidental symmetry that the ...Standard Model of elementary particle physics has, and published the most stringent limit on the charged lepton flavor violating decay μ+→e+γ: BR(μ+→e+γ) <4.2×10-13 at 90% confidence level. The MEG detector has been upgraded in order to reach a sensitivity of 6×10-14. The basic principle of MEG II is to achieve the highest possible sensitivity using the full muon beam intensity at the Paul Scherrer Institute (7×107 muons/s) with an upgraded detector. The main improvements are better rate capability of all sub-detectors and improved resolutions while keeping the same detector concept. In this paper, we present the current status of the preparation, integration and commissioning of the MEG II detector in the recent engineering runs.
A novel Resistive Plate Chamber (RPC) was designed with Diamond-Like Carbon
(DLC) electrodes and performance studies were carried out for 384$\,\mathrm{\mu
m}$ gap configuration with a ...$2\,\mathrm{cm}\times2\,\mathrm{cm}$ prototype.
The use of thin films coated with DLC enables an ultra-low mass design of $<
0.1\%\,X_0$ with up to a four-layer configuration. At the same time, 42% MIP
efficiency, and 180 ps timing resolution per layer were achieved in a
measurement performed under a $1\,\mathrm{MHz/cm^2}$ non-MIP charged particle
beam. In addition, we propose a further improved design for a
$20\,\mathrm{cm}$-scale detector that can achieve 90% four-layer efficiency in
an even higher $4\,\mathrm{MHz/cm^2}$ beam. In this paper, we describe the
detector design, present the results of performance measurements, and
characterize the rate capability of the DLC-based RPCs with a performance
projection for an improved design.
A new type of resistive plate chamber with thin-film electrodes based on diamond-like carbon is under development for background identification in the MEG II experiment. Installed in a low-momentum ...and high-intensity muon beam, the detector is required to have extremely low mass and a high rate capability. A single-layer prototype detector with 2 cm \(\times\) 2 cm size was constructed and evaluated to have a high rate capability of 1 MHz/cm\(^2\) low-momentum muons. For a higher rate capability and scalability of the detector size, the electrodes to supply high voltage were segmented at a 1 cm pitch by implementing a conductive pattern on diamond-like carbon. Using the new electrodes, a four-layer prototype detector was constructed and evaluated to have a 46% detection efficiency with only a single layer active at a rate of \(\cal O\)(10 kHz). The result with the new electrodes is promising to achieve the required detection efficiency of 90% at a rate of 4 MHz/cm\(^2\) with all the layers active.
A new type of resistive plate chamber (RPC) is under development using thin-film resistive electrodes based on diamond-like carbon (DLC). Planned to be put on the path of high-intensity low-momentum ...muon beam of the MEG II experiment, this detector is required to be high-rate capable and ultra-low mass. Using a prototype detector with 2 cm \(\times\) 2 cm size and 0.1 % \(X_0\) material budget, performance studies were conducted for MIP detection efficiency, timing resolution and high rate capability in low-momentum muon beam. In this paper, the measured performance is presented including the result with low-momentum muon beam at rate up to 1 \(\mathrm{MHz/cm^2}\). Based on the result, the expected performance of the full-scale detector in the MEG~II experiment is also discussed.
