Technical Proposal for FASER: ForwArd Search ExpeRiment at the LHC

FASER is a proposed small and inexpensive experiment designed to search for light, weakly-interacting particles during Run 3 of the LHC from 2021-23. Such particles may be produced in large numbers along the beam collision axis, travel for hundreds of meters without interacting, and then decay to standard model particles. To search for such events, FASER will be located 480 m downstream of the ATLAS IP in the unused service tunnel TI12 and be sensitive to particles that decay in a cylindrical volume with radius R=10 cm and length L=1.5 m. FASER will complement the LHC's existing physics program, extending its discovery potential to a host of new, light particles, with potentially far-reaching implications for particle physics and cosmology. This document describes the technical details of the FASER detector components: the magnets, the tracker, the scintillator system, and the calorimeter, as well as the trigger and readout system. The preparatory work that is needed to install and operate the detector, including civil engineering, transport, and integration with various services is also presented. The information presented includes preliminary cost estimates for the detector components and the infrastructure work, as well as a timeline for the design, construction, and installation of the experiment.Comment: 82 pages, 62 figures; submitted to the CERN LHCC on 7 November 201

The FASER Detector

FASER, the ForwArd Search ExpeRiment, is an experiment dedicated to searching for light, extremely weakly-interacting particles at CERN's Large Hadron Collider (LHC). Such particles may be produced in the very forward direction of the LHC's high-energy collisions and then decay to visible particles inside the FASER detector, which is placed 480 m downstream of the ATLAS interaction point, aligned with the beam collisions axis. FASER also includes a sub-detector, FASER$\nu$, designed to detect neutrinos produced in the LHC collisions and to study their properties. In this paper, each component of the FASER detector is described in detail, as well as the installation of the experiment system and its commissioning using cosmic-rays collected in September 2021 and during the LHC pilot beam test carried out in October 2021. FASER will start taking LHC collision data in 2022, and will run throughout LHC Run 3

Chaise Longue (LC/4)

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Chaise Longue (LC/4)

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Study of the Extracted Beam Energy as a Function of Operational Parameters of a Medical Cyclotron

The medical cyclotron at the Bern University Hospital (Inselspital) is used for both routine 18 F production for Positron Emission Tomography (PET) and multidisciplinary research. It provides proton beams of variable intensity at a nominal fixed energy of 18 MeV. Several scientific activities, such as the measurement of nuclear reaction cross-sections or the production of non-conventional radioisotopes for medical applications, require a precise knowledge of the energy of the beam extracted from the accelerator. For this purpose, a study of the beam energy was performed as a function of cyclotron operational parameters, such as the magnetic field in the dipole magnet or the position of the extraction foil. The beam energy was measured at the end of the 6 m long Beam Transfer Line (BTL) by deflecting the accelerated protons by means of a dipole electromagnet and by assessing the deflection angle with a beam profile detector

Wavelet-based detection of ventricular ectopic beats in heart rate signals

The purpose of this work is to present a method based on the continuous wavelet transform for the detection of heart rhythm perturbations called ventricular ectopic beats. Direct identification of these abrupt changes in heart rate signals is determinant for clinical prognosis since several previous studies have shown that ventricular ectopic beats are potential factors in the triggering of ventricular tachyarrhythmias. The proposed method is a three-step procedure: time-warping-based preprocessing, detection using maxima of the continuous wavelet transform, and final selection of relevant patterns. Several examples of application to heart rate signals retrieved from implanted cardioverter-defibrillators are presented and illustrate the efficiency of the method

ALVAREZ DRIFT TUBE LINAC FOR MEDICAL APPLICATIONS IN THE FRAMEWORK OF HITRIPLUS PROJECT

A first beam dynamics and RF design of an Alvarez-type drift tube linac (DTL) has been defined in the framework of the EU project, HITRIplus. It is meant primarily as a carbon (12C4+) and helium (4He2+) ion injector of a compact synchrotron for patient treatment. As a second implemen-tation, helium particle acceleration with a higher duty cycle (10%) enables radioisotope production. The 352.2 MHz structure efficiently accelerates ion species with A/q=3 and 2, in the energy range from 1 to 5 MeV/u and for a beam current up to ~0.5 mA. The design extends to a full length of ~6.4 meters. Permanent magnet quadrupoles are utilized all along the DTL for focusing both ion beams. This paper presents a first-phase analysis towards a realistic DTL de-sign capable of providing full beam transmission and min-imum overall emittance increase for both A/q values

Structuration des discours au sein de Twitter durant l’élection présidentielle française de 2017: Entre agenda politique et représentations sociales

International audienceThis article describes and studies information exchanges on Twitter during the 2017 French presidential election campaign. Grounded in the theoretical framework of social representations, it investigates the discourses of the support communities of the five main candidates, using methods drawn from network analysis and the statistical analysis of text data. The findings highlight the weight of the psycho-sociological processes that regulate the way social groups relate to their political environment, and the way in which this relationship materializes through the structuring of communication on Twitter. This article thus shows how the ideological background of the different political communities can regulate their perception of certain objects of social representation connected to the presidential campaign.Cette étude se fixe comme objectif de décrire et d’étudier les échanges d’informations au sein de Twitter pendant la campagne électorale pour la présidentielle française de 2017. Inscrite dans le cadre théorique des représentations sociales, elle consiste à investiguer les discours des communautés de soutien des cinq principaux candidats à partir de méthodes relevant de l’analyse des réseaux et de l’analyse statistique des données textuelles. Les résultats mettent en lumière le poids des processus psycho-sociologiques qui régulent le rapport des groupes sociaux à leur environnement politique et la manière dont ils s’actualisent dans la structuration des échanges au sein de Twitter. Ils montrent ainsi comment l’inscription idéologique des différentes communautés politiques peut réguler leur perception de certains objets de représentation sociale en lien avec la campagne présidentielle