474 research outputs found
Single Spin Asymmetries on a transversely polarised proton target at COMPASS
COMPASS is a running fixed-target experiment at the CERN SPS with a rich physics program focused on nucleon spin structure and on hadron spectroscopy. One of the main goals of the spin program is the measurement of the transverse spin effects in semi-inclusive DIS off transversely polarised nucleons. In the years 2002, 2003 and 2004 data have been taken using a 160 naturally polarised beam and a deuterium target () transversely polarised respect to the beam direction. In 2007 the run year has been devoted to collect data with a proton () target. The preliminary results for the Collins and Sivers asymmetries, extracted from the 2007 data with transverse target polarisation, are presented here. Results are also compared with existing model predictions
Slimmable Encoders for Flexible Split DNNs in Bandwidth and Resource Constrained IoT Systems
The execution of large deep neural networks (DNN) at mobile edge devices
requires considerable consumption of critical resources, such as energy, while
imposing demands on hardware capabilities. In approaches based on edge
computing the execution of the models is offloaded to a compute-capable device
positioned at the edge of 5G infrastructures. The main issue of the latter
class of approaches is the need to transport information-rich signals over
wireless links with limited and time-varying capacity. The recent split
computing paradigm attempts to resolve this impasse by distributing the
execution of DNN models across the layers of the systems to reduce the amount
of data to be transmitted while imposing minimal computing load on mobile
devices. In this context, we propose a novel split computing approach based on
slimmable ensemble encoders. The key advantage of our design is the ability to
adapt computational load and transmitted data size in real-time with minimal
overhead and time. This is in contrast with existing approaches, where the same
adaptation requires costly context switching and model loading. Moreover, our
model outperforms existing solutions in terms of compression efficacy and
execution time, especially in the context of weak mobile devices. We present a
comprehensive comparison with the most advanced split computing solutions, as
well as an experimental evaluation on GPU-less devices
Study of MicroPattern Gaseous detectors with novel nanodiamond based photocathodes for single photon detection in EIC RICH
Identification of high momentum hadrons at the future EIC is crucial, gaseous
RICH detectors are therefore viable option. Compact collider setups impose to
construct RICHes with small radiator length, hence significantly limiting the
number of detected photons. More photons can be detected in the far UV region,
using a windowless RICH approach. QE of CsI degrades under strong irradiation
and air contamination. Nanodiamond based photocathodes (PCs) are being
developed as an alternative to CsI. Recent development of layers of
hydrogenated nanodiamond powders as an alternative photosensitive material and
their performance, when coupled to the THick Gaseous Electron Multipliers
(THGEM)-based detectors, are the objects of an ongoing R\&D. We report about
the initial phase of our studies.Comment: 3 pages, 5 figures, RICH2018 conference proceedin
Remote alignment of large mirror array for RICH detectors
Image focusing in large RICH detectors is obtained by composite systems of mirror elements. Monitoring and adjusting the alignment of the mirror elements during data taking are important handles to improve the detector resolution. Mirror adjustment via piezoelectric actuators can combine unprecedented accuracy and match some fundamental requirements: the detector material budget can be kept low and the high purity of the gas radiator can be preserved, a prerequisite when UV photons are detected. A system based on this principle, well suited for COMPASS RICH-1 mirrors, is proposed
RHIP, a Radio-controlled High-Voltage Insulated Picoammeter and its usage in studying ion backflow in MPGD-based photon detectors
A picoammeter system has been developed and engineering. It consists in a
current-voltage converter, based on an operational amplifier with very low
input current, a high precision ADC, a radio controlled data acquisition unit
and the computer-based control, visualization and storage. The precision is of
the order of a tenth of picoampers and it can measure currents between
electrodes at potentials up to 8 kV. The system is battery powered and a number
of strategies have been implemented to limit the power consumption. The system
is designed for multichannel applications, up to 256 parallel channels. The
overall implementation is cost-effective to make the availability of
multichannel setups easily affordable. The design, implementation and
performance of the picoammeter system are described in detail as well as a an
application: the measurement of ion backflow in MPGD-based photon detectors.Comment: 5th International Conference on Micro-Pattern Gas Detectors
(MPGD2017), presentation by Silvia Dalla Torr
Development of large area resistive electrodes for ATLAS NSW Micromegas
Micromegas with resistive anodes will be used for the NSW upgrades of the ATLAS experiment at LHC. Resistive electrodes are used in MPGD devices to prevent sparks in high-rate operation. Large-area resistive electrodes for Micromegas have been developed using two different technologies: screen printing and carbon sputtering. The maximum resistive foil size is 45 Ă— 220 cm with a printed pattern of 425-ÎĽm pitch strips. These technologies are also suitable for mass production. Prototypes of a production model series have been successfully produced. In this paper, we report the development, the production status, and the test results of resistive Micromegas
Characterization of the water diffusion in GEM foil material
Systematic studies on the GEM foil material are performed to measure the moisture diffusion rate and saturation level.These studies are important because the presence of this compound inside the detector’s foil can possibly change its mechanical and electrical properties,and in such a way,the detector performance can be affected.To understand this phenomenon,a model is developed with COMSOL Multiphysicsv.4.3 which described the adsorption and diffusion within the geometry of GEM foil,the concentration profiles and the time required to saturate the foil.The COMSOL model is verified by experimental observations on a GEM foil sample.This note will describe the model and its experimental verification results
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