LINAC4 Laser Profile and Emittance Meter Commissioning
357
A. Goldblatt, O.Ø. Andreassen, T. Hofmann, F. Roncarolo, J. Tagg
CERN, Meyrin, Switzerland
G.E. Boorman, A. Bosco, S.M. Gibson
Royal Holloway, University of London, Surrey, United Kingdom
The LINAC4 is now equipped with two laser profile and emittance meters, basically non destructive and not limited by beam power density. A pulsed laser is transported through fibres and focused into the 160 MeV H− beam. Its interaction with the H− ions detaches electrons that are collected by an electron-multiplier, while the resultingH0 particles, after being separated from the main H− beam by a dipole magnet, are recorded by a diamond strip detector, few meters away from the interaction point. The emittance and profile are reconstructed from the laser step by step scan of the beam. After several years of feasibility tests and prototyping, this paper will present all details about the final HW and SW implementation and the 2022 experimental results.
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Experimental Investigation of Gold Coated Tungsten Wires Emissivity for Applications in Particle Accelerators
438
A. Navarro Fernandez, M. Martin Nieto, F. Roncarolo
CERN, Meyrin, Switzerland
The operation of wire grids and wire scanners as beam profile monitors can be heavily affected, both in terms of measurement accuracy and wire integrity, by the thermal response of the wires to the energy deposited by the charged particles. Accurate measurements of material emissivity are crucial, as Radiative Cooling represent the most relevant cooling process. In this work, we present a method for emissivity measurements of gold-coated tungsten wires based on calorimetric techniques. The dedicated electrical setup allowed allowed transient and steady state measurements for temperatures up to 2000 K. A theoretical description of the measurement technique will be followed up by the electrical set up description and a detailed discussion about the measured results and uncertainties.
Assessing the Performance of the New Beam Wire Scanners for the CERN LHC Injectors
443
S. Di Carlo, W. Andreazza, D. Belohrad, J. Emery, J.C. Esteban Felipe, A. Goldblatt, D. Gudkov, A. Guerrero, S. Jackson, G.O. Lacarrere, M. Martin Nieto, A.T. Rinaldi, F. Roncarolo, C. Schillinger, R. Veness
CERN, Meyrin, Switzerland
The ability of reliably measuring the transverse beam profile in its injectors is essential for the operation of the LHC. This report aims to assess the reliability, stability, and reproducibility of the new generation of beam wire scanners developed at CERN in the framework of the LHC Injectors Upgrade (LIU). The study includes data from the over 60000 scans performed in 2021 and 2022, with a special focus on reproducibility, investigation of optimal operational settings to ensure a large dynamic range, and evaluation of absolute accuracy through comparison with other instruments present in the injectors.
Secondary Emission Monitor Simulation, Measurements and Machine Learning Application Studies for CERN Fixed Target Beamlines
476
L. Parsons França, M. Duraffourg, F. Roncarolo, F.M. Velotti
CERN, Meyrin, Switzerland
E. Kukstas, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch, H.D. Zhang
Cockcroft Institute, Warrington, Cheshire, United Kingdom
Funding:This work was supported by CERN and the STFC Liverpool Centre for Doctoral Training on Data Intensive Science (LIV. DAT) under grant agreement ST/P006752/1. The CERN fixed target experimental areas have recently acquired new importance thanks to newly proposed experiments, such as those linked to Physics Beyond Colliders (PBC) activities. Secondary Emission Monitors (SEMs) are the instruments currently used for measuring beam current, position and size in these areas. Guaranteeing their reliability, resistance to radiation and measurement precision is challenging. This paper presents the studies being conducted to understand ageing effects on SEM devices, to calibrate and optimise the SEM design for future use in these beamlines. These include feasibility studies for the application of machine learning techniques, with the objective of expanding the range of tools available for data analysis.
Fast Spill Monitor Studies for the SPS Fixed Target Beams
522
F. Roncarolo, P.A. Arrutia Sota, D. Belohrad, E. Calvo Giraldo, E. Effinger, M.A. Fraser, V. Kain, M. Martin Nieto, S. Mazzoni, I. Ortega Ruiz, J. Tan, F.M. Velotti, C. Zamantzas
CERN, Meyrin, Switzerland
M. Bergamaschi
MPI-P, München, Germany
At the CERN Super Proton Synchrotron (SPS) the proton beam is supplied to the fixed target experiments in the North Area facility (NA) via a slow extraction process, taking place at 400 GeV. The monitoring of the spill quality during the extraction, lasting 4.8 seconds with the present SPS setup, is of high interest for minimising beam losses and providing the users with uniform proton-on-target rates. The monitor development challenges include the need for detecting, sampling, processing and publishing the data at rates ranging from few hundred Hz to support the present operation to several hundreds of MHz to serve future experiments proposed within the Physics Beyond Collider (PBC) programme. This paper will give an overview of the ongoing studies for optimizing the existing monitors performances and of the R&D dedicated to future developments. Different techniques are being explored, from Secondary Emission Monitors to Optical Transition Radiation (OTR), Gas Scintillation and Cherenkov detectors. Expected ultimate limitations from the various methods will be presented, together with 2022 experimental results, for example with a recently refurbished OTR detector.
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