Multilayer film shields for the protection of PMT from constant magnetic field

This is the Published Version made available with the permission of the publisher.Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results of measurements of shielding effectiveness of multilayer film magnetic shields on PMT-85 are presented. Shields were formed by alternating layers of a material with high magnetic permeability (Ni-Fe) and high electric conductivity—Cu. The maximum number of bilayers reached 45. It is shown that in weak magnetic fields up to 0.5 mT, the output signal amplitude from PMT-85 does not change for all used multilayer shields. In strong magnetic field of 2–4 mT, the output signal amplitude decrease with 10%–40% depending from the number of layers in the shield. The Pulse distribution of PMT-85 in magnetic field 0.2–4 mT slightly changed in the range 1.1%–1.3% for the case when the number of layers do not exceed 10 and practically did not change for a shield with 45 double layers

Multilayer film shields for the protection of PMT from constant magnetic field

This is the Published Version made available with the permission of the publisher.Photomultiplier tubes (PMTs) are widely used in physical experiments as well as in applied devices. PMTs are sensitive to magnetic field, so creation of effective magnetic shields for their protection is very important. In this paper, the results of measurements of shielding effectiveness of multilayer film magnetic shields on PMT-85 are presented. Shields were formed by alternating layers of a material with high magnetic permeability (Ni-Fe) and high electric conductivity—Cu. The maximum number of bilayers reached 45. It is shown that in weak magnetic fields up to 0.5 mT, the output signal amplitude from PMT-85 does not change for all used multilayer shields. In strong magnetic field of 2–4 mT, the output signal amplitude decrease with 10%–40% depending from the number of layers in the shield. The Pulse distribution of PMT-85 in magnetic field 0.2–4 mT slightly changed in the range 1.1%–1.3% for the case when the number of layers do not exceed 10 and practically did not change for a shield with 45 double layers

SiPM-based azimuthal position sensor in ANITA-IV Hi-Cal Antarctic balloon experiment

Hi-Cal (High-Altitude Calibration) is a balloon-borne experiment that will be launched in December, 2016 in Antarctica following ANITA-IV (Antarctic Impulsive Transient Antenna) and will generate a broad-band pulse over the frequency range expected from radiation induced by a cosmic ray shower. Here, we describe a device based on an array of silicon photomultipliers (SiPMs) for determination of the azimuthal position of Hi-Cal. The angular resolution of the device is about 3 degrees. Since at the float altitude of ~38 km the pressure will be ~0.5 mbar and temperature ~ − 20 °C, the equipment has been tested in a chamber over a range of corresponding pressures (0.5 ÷ 1000) mbar and temperatures (−40 ÷ +50) °C

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

Upregulation of α7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides

BACKGROUND: The alpha-7 nicotinic acetylcholine receptor (alpha7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the alpha7-nAChR, or peptide modulation of receptor expression. METHODOLOGY/PRINCIPAL FINDINGS: This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the alpha7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of alpha7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. CONCLUSIONS/SIGNIFICANCE: The results reported here demonstrate a hitherto unknown relationship between the alpha7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration

ФОТОЭЛЕКТРОННЫЕ УМНОЖИТЕЛИ С МНОГОСЛОЙНЫМИ ПЛЕНОЧНЫМИ ЭКРАНАМИ ДЛЯ ЗАЩИТЫ ОТ ВОЗДЕЙСТВИЯ ВНЕШНИХ ПОСТОЯННЫХ МАГНИТНЫХ ПОЛЕЙ

The effectiveness of the screening constant magnetic field is multi-layered film screens system of NiFe/Cu, formed on the cylindrical housing of photomultiplier tubes, and compared with screen-based steel material – brand 80NHS permalloy. It is shown that the most effective is the screen on the basis of the multilayered film screens, which provide shielding effectiveness value 8–10 in magnetic fields with induction of 0,1–1 mT, and 80–100 – in magnetic fields with induction of 2–4 mT , which is 4–5 times higher than for the screen of the material 80NHS.Изучена эффективность экранирования постоянного магнитного поля многослойными пленочными экранами системы NiFe/Cu, сформированными на цилиндрических корпусах фотоэлектронных умножителей, и проведено сопоставление с экраном на основе металлургического материала – пермаллой марки 80НХС. Показано, что наиболее эффективным является экран на основе многослойных пленочных структур, который обеспечивает значения эффективности экранирования 8–10 в магнитных полях с индукцией 0,1–1 мТл, и 80–100 – в магнитных полях с индукцией 2–4 мТл, что в 4–5 раз выше, чем для экрана из материала 80НХС

Measurement of associated charm production induced by 400 GeV/c protons

An important input for the interpretation of the measurements of the SHiP ex- periment is a good knowledge of the differential charm production cross section, including cascade production. This is a proposal to measure the associated charm production cross section, employing the SPS 400 GeV/c proton beam and a replica of the first two interaction lengths of the SHiP target. The detection of the produc- tion and decay of charmed hadron in the target will be performed through nuclear emulsion films, employed in an Emulsion Cloud Chamber target structure. In order to measure charge and momentum of decay daughters, we intend to build a mag- netic spectrometer using silicon pixel, scintillating fibre and drift tube detectors. A muon tagger will be built using RPCs. An optimization run is scheduled in 2018, while the full measurement will be performed after the second LHC Long Shutdown

The SHiP experiment at the proposed CERN SPS Beam Dump Facility

The Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50 m long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400 GeV protons, the experiment aims at profiting from the 4 x 10(19) protons per year that are currently unexploited at the SPS, over a period of 5-10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few MeV/c(2) up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end

The experimental facility for the Search for Hidden Particles at the CERN SPS

The International School for Advanced Studies (SISSA) logo The International School for Advanced Studies (SISSA) logo The following article is OPEN ACCESS The experimental facility for the Search for Hidden Particles at the CERN SPS C. Ahdida44, R. Albanese14,a, A. Alexandrov14, A. Anokhina39, S. Aoki18, G. Arduini44, E. Atkin38, N. Azorskiy29, J.J. Back54, A. Bagulya32Show full author list Published 25 March 2019 • © 2019 CERN Journal of Instrumentation, Volume 14, March 2019 Download Article PDF References Download PDF 543 Total downloads 7 7 total citations on Dimensions. Article has an altmetric score of 1 Turn on MathJax Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 GeV/c proton beam offers a unique opportunity to explore the Hidden Sector [1–3]. The proposed experiment is an intensity frontier experiment which is capable of searching for hidden particles through both visible decays and through scattering signatures from recoil of electrons or nuclei. The high-intensity experimental facility developed by the SHiP Collaboration is based on a number of key features and developments which provide the possibility of probing a large part of the parameter space for a wide range of models with light long-lived super-weakly interacting particles with masses up to Script O(10) GeV/c2 in an environment of extremely clean background conditions. This paper describes the proposal for the experimental facility together with the most important feasibility studies. The paper focuses on the challenging new ideas behind the beam extraction and beam delivery, the proton beam dump, and the suppression of beam-induced background

Fast simulation of muons produced at the SHiP experiment using generative adversarial networks

This paper presents a fast approach to simulating muons produced in interactions of the SPS proton beams with the target of the SHiP experiment. The SHiP experiment will be able to search for new long-lived particles produced in a 400 GeV/c SPS proton beam dump and which travel distances between fifty metres and tens of kilometers. The SHiP detector needs to operate under ultra-low background conditions and requires large simulated samples of muon induced background processes. Through the use of Generative Adversarial Networks it is possible to emulate the simulation of the interaction of 400 GeV/c proton beams with the SHiP target, an otherwise computationally intensive process. For the simulation requirements of the SHiP experiment, generative networks are capable of approximating the full simulation of the dense fixed target, offering a speed increase by a factor of Script O(106). To evaluate the performance of such an approach, comparisons of the distributions of reconstructed muon momenta in SHiP's spectrometer between samples using the full simulation and samples produced through generative models are presented. The methods discussed in this paper can be generalised and applied to modelling any non-discrete multi-dimensional distribution