For the upgrade of the innermost station of the forward muon spectrometer of the ATLAS experiment large Micromegas (MM) detectors of 2 and 3 m2 with 4 active layers each are foreseen. Four types of ...MM chambers are produced among four sites. Each sites has to deliver 32 quadruplets or 128 active planes. The tiny 120μm distance between the 600 V resistive strip anodes and the ground micro-meshes for these large areas require adequate and well adapted cleaning procedures to guarantee high voltage stability. This is particularly critical for strip shaped surfaces made from resistive material where remnants from the lithographic production processes must be completely removed. The procedure foreseen a visual inspections to be carried on during cleaning and assembly procedures; a wet cleaning procedure to remove dust and possible ionic components of salts from the anode surfaces; a dry cleaning procedure to remove dust; HV tests to be done to validate the cleaning. The cleaning procedure will be illustrated for a New Small Wheel (NSW) Outer Small Module (SM2) of 2 m2.
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The design, construction and test of a charged particle detector made of scintillation counters read by Silicon Photomultipliers (SiPM) is described. The detector, which operates in vacuum and is ...used as a veto counter in the NA62 experiment at CERN, has a single channel time resolution of 1.14 ns, a spatial resolution of ~2.5 mm and an efficiency very close to 1 for penetrating charged particles.
The NA62 experiment 1 will measure the BR (K super(+) arrow right capital pi super(+)vv) to within about 10%. To reject the dominant background from final state photons, the large-angle vetoes (LAVs) ...must detect particles with better than 1 ns time resolution and 10% energy resolution over a very large energy range. A low threshold, large dynamic range, Time-over-threshold based solution has been developed for the LAV front end electronics. Our custom 32 channel 9U board uses a pair of low threshold discriminators for each channel to produce LVDS logic signals. The achieved time resolution obtained in laboratory, coupled to an HPTDC based readout board, is similar to 150 ps.
Readout studies for the HIKE main electromagnetic calorimeter Francesconi, M.; Ambrosino, F.; Antonelli, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
October 2024, Volume:
1067
Journal Article
Peer reviewed
The High-Intensity Kaon Experiment (HIKE) is a proposed future kaon experiment designed for the CERN SPS accelerator. To cope with a planned increase of beam intensity by a factor of 4 with respect ...to the current NA62 experiment, the new Main Electromagnetic Calorimeter (MEC) has to provide a similar improvement in time resolution over the current Liquid Krypton calorimeter, down to ≈100ps for a 40GeV photon, while maintaining a comparable energy and spatial resolution. To achieve these goals, the planned detector consists of a shashlik calorimeter paired with high-resolution analog to digital converter for both energy deposit and arrival time estimates, operating at fast sample rates (∼1GHz).
This contribution describes a prototype of the readout system using commercial “off-the-shelf” boards. In particular, we focused on feature extraction and tested it using a pulse generator. We included a data readout logic based on the TCP/IP protocol allows for easy deployment in beam tests.
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A precision measurement of the ratio RK of the rates of kaon leptonic decays K±→e±ν and K±→μ±ν with the full data sample collected by the NA62 experiment at CERN in 2007–2008 is reported. The result, ...obtained by analysing ∼150000 reconstructed K±→e±ν candidates with 11% background contamination, is RK=(2.488±0.010)×10−5, in agreement with the Standard Model expectation.
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This paper shows the experimental results obtained using a nanocoating (developed by ISTEC-C.N.R.) applied to the slippers of an axial piston pump to reduce the friction losses in order to improve ...the pump overall efficiency map. It is well known that the mechanical power losses in a hydraulic pump come from the friction between parts in relative motion. The need to provide, especially at low rotational speed, hydrodynamic lift causes power losses in terms of volumetric and mechanical efficiency, due to the contrasting need to increase leakage to provide lubrication and to keep a minimum clearance in meatus to limit the volumetric losses. The application of special surface treatments have been exploited in pioneering works in the past, trying different surface finishing or adding ceramic or heterogeneous metallic layers, but the potential of structured coatings at nanoscale, with superhydrophobic and oleophobic characteristics, has never been exploited. Using a dedicated test rig developed at IMAMOTER-C.N.R., able to ensure hydrostatic working condition during the mutual rotation between the slippers and the swash plate, the functional performance of the nanocoated slippers' surface have been studied. In the first part of the paper, the functionalization method is presented; in the second part, a comparison between the experimental performances of coated and uncoated surfaces is showed.
The NA62 LAV front-end electronics Antonelli, A; Corradi, G; Moulson, M ...
Journal of instrumentation,
01/2012, Volume:
7, Issue:
1
Journal Article
Peer reviewed
Open access
The branching ratio for the decay K super(+) arrow right capital pi super(+) upsilon upsilon is sensitive to new physics; the NA62 experiment will measure it to within about 10%. To reject the ...dominant background from channels with final state photons, the large-angle vetoes (LAVs) must detect particles with better than 1 ns time resolution and 10% energy resolution over a very large energy range. Our custom readout board uses a time-over-threshold discriminator coupled to a TDC as a straightforward solution to satisfy these requirements. A prototype of the readout system was extensively tested together with the ANTI-A2 large angle veto module at CERN in summer 2010.
The branching ratio (BR) for the decay K+ → π+ν is a sensitive probe for new physics. The NA62 experiment at the CERN SPS will measure this BR to within about 10 . To reject the background from ...dominant kaon decays with final state photons, the large-angle photon vetoes (LAVs) must detect photons of energy as low as 200 MeV with an inefficiency of less than 10−4. The LAV detectors make use of lead glass blocks recycled from the OPAL electromagnetic calorimeter barrel. We describe the mechanical design and challenges faced during construction, the characterization of the lead glass blocks and solutions adopted for monitoring their performance, and the development of front-end electronics to allow simultaneous time and energy measurements over an extended dynamic range using the time-over-threshold technique. Our results are based on test-beam data and are reproduced by a detailed Monte Carlo simulation that includes the readout chain.
We have measured the cross section σ(e+e−→π+π−γ(γ)) at DAΦNE, the Frascati ϕ-factory, using events with initial state radiation photons emitted at small angle and inclusive of final state radiation. ...We present the analysis of a new data set corresponding to an integrated luminosity of 240 pb−1. We have achieved a reduced systematic uncertainty with respect to previously published KLOE results. From the cross section we obtain the pion form factor and the contribution to the muon magnetic anomaly from two-pion states in the mass range 0.592<Mππ<0.975 GeV. For the latter we find Δππaμ=(387.2±0.5stat±2.4exp±2.3th)×10−10.
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