The H and D Polarized Target for Spin–Filtering Measurements at COSY

In the main frame of the PAX (Polarized Antiproton eXperiments) collaboration, which engaged the challenging purpose of polarizing antiproton beams, the possibility to have H or D polarized targets requires a daily switchable source and its diagnostics: mainly change is a dual cavity tunable for H and D. The commissioning of PAX has been fullfilled, for the transverse case, on the COSY (COoler SYnchrotron) proton ring, achieving milestones on spin–dependent cross–section measurements. Now the longitudinal case could provide sensitive polarization results. An H or D source allows the exploration of the spin–filtering process with a deuterium polarized target, and opens new chances for testing Time Reversal Invariance at COSY (TRIC)

The ASTAROTH project

The most discussed topic in direct search for dark matter is arguably the verification of the DAMA claim. In fact, the observed annual modulation of the signal rate in an array of NaI(Tl) detectors can be interpreted as the awaited signature of dark matter interaction. Several experimental groups are currently engaged in the attempt to verify such a game-changing claim with the same target material. However, all present-day designs are based on a light readout via Photomultiplier Tubes, whose high noise makes it challenging to achieve a low background in the 1-6 keV energy region of the signal. Even harder it would be to break below 1 keV energy threshold, where a large fraction of the signal potentially awaits to be uncovered. ASTAROTH is an R\&D project to overcome these limitations by using Silicon Photomultipliers (SiPM) matrices to collect scintillation light from NaI(Tl). The all-active design based on cubic crystals is operating in the 87-150 K temperature range where SiPM noise can be even a hundred times lower with respect to PMTs. The cryostat was developed following an innovative design and is based on a copper chamber immersed in a liquid argon bath that can be instrumented as a veto detector. We have characterized separately the crystal and the SiPM response at low temperature and we have proceeded to the first operation of a NaI(Tl) crystal read by SiPM in cryogeny.Comment: proceedings of the LRT 2022 conferenc

Towards a muon collider

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work

First consideration on magnetic field for an accumulation cell

The short memo introduces the use of high temperature superconductors for the transverse field of a polarized gaseous target cell for PAX

Electromagnetic Study of a Round Coil Superferric Magnet

A novel type of superferric magnets suitable to arbitrary multipole orders was proposed by I. F. Malyshev and later by V. Kashikhin. This new topology, which we refer to as round coil superferric magnets (RCSM), allows a great simplification of the superconducting part, which in the simplest case may be composed by a single round coil, which has intrinsically a rather large bending radius allowing the use of strain-sensitive superconductors. INFN is designing and building a prototype of a multipolar corrector magnet based on this geometry and using MgB2 tapes. In this paper, we investigate a number of issues pertaining to the electromagnetic characteristics of RCSM. The RCSM magnetic has inherently even harmonics, in addition to usual odd ones and a solenoidal component. Either (but not both) disappears when integrated using a one-coil or a two-coil specular design. We investigate the effect of saturation on the multipolar components and on the load line, since in RCSM, saturation plays a role that differs both from conventional superferric magnets and from round yoke design type

Study of a Sextupole Round Coil Superferric Magnet

Abstract: The LASA Laboratory (INFN, Milan) is developing a new type of superferric magnets suitable to arbitrary multipole order, which we refer to as round coil superferric magnets. It is based on the previous proposal of I. F. Malyshev and V. Kashikhin. This type of magnet is suitable for strain-sensitive superconductors because it only uses a single round coil, which has a large bending radius, to create the magnetic field. The round yoke with arbitrary multipoles is able to create the desired harmonic component for the magnet. A preliminary electromagnetic design of such magnet in sextupole configuration was presented, using MgB2 superconducting tape for the coil. In this paper, we present the advances in the study for the construction of the prototype. We analyze the electromagnetic properties of the coil and of the round multipole iron yoke, focusing on the optimization of the main desired multipole harmonic. We also study the mechanics and quench protection, considering a new type of MgB2 superconducting cable for the coils. At the end of 2017, the magnet will be assembled in the LASA laboratories and then tested in 2018

A SUPERCONDUCTING MAGNETS SYSTEMS FOR A LOW BETA SECTION AT COSY AND AD

In the framework of the FAIR project (GSI, Darmstadt, D), the PAX collaboration has suggested new experiments using polarized antiprotons. The central physics issue is now to study the polarization build-up by spin filtering of antiprotons via multiple passages through an internal polarized gas target. The goals for spin-filtering experiments with protons at COSY Forrschungzentrum Juelich, D) are to test our understanding of the spin-filtering processes and to commission the setup for the experiments with antiprotons at the AD (CERN). Spin-filtering experiments with antiprotons at the AD will allow us to determine the total spin-dependent transversal and longitudinal cross sections. The low-beta section at COSY is composed of two superconducting quadrupole magnets on each side of the target, while at the AD, we will use three quadrupoles on each side. Technical problems and details of the superconducting quadrupoles with their respective cryogenics will be discussed. A flexible cryogenic system fitting at COSY and AD ring characterized by a low liquid helium consumption will be discussed. The status of the construction of the quadrupoles will be reported as well

Lattice studies for low-beta sections at COSY and AD of CERN for spin-filtering studies

In the framework of the FAIR project, the PAX collaboration has suggested new experiments using polarized antiprotons . The central physics issue is now to study the polarization build-up by spin filtering of antiprotons via multiple passage through an internal polarized gas target. The goals for spin-filtering experiments with protons at COSY are to test our understanding of the spin-filtering processes and to commission the setup for the experiments with antiprotons at the Antiproton Decelerator (CERN). Spin-filtering experiments with antiprotons at the AD will allow us to determine the total spin-dependent transversal and longitudinal cross sections

Electrical Quality Assurance for the NbTi Coils of the HL-LHC High Order Corrector Magnets

The INFN-LASA laboratory (Milano, Italy) is involved in the High-Luminosity LHC program for the design, construction, and test of 54 superconducting high-order corrector magnets. One of the challenging project stages was the transition from the construction of laboratory prototypes to the series production, awarded to industries, with the demanding requirement of maintaining high-quality production standards. Common and custom quality assurance (QA) methods were adopted for the analysis of the electrical characteristics of the coils. This paper discusses in detail the principle of the methods, their expected sensitivity, and the final observed effectiveness on the 510 produced coils. In some cases, the methods led to early defect detection thus avoiding possible severe damages during the final cold test that have already occurred for a prototype magnet not subject to the QA procedures described in this paper