English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The Large Hadron Collider (LHC) Injector Upgrade (LIU) Project at CERN calls for increasing beam intensity for the LHC accelerator chain. Some machine components will not survive the new beam characteristics and need to be rebuilt for the new challenging scenario. This is particularly true for beam intercepting devices (BIDs) such as dumps, collimators, and absorber/scrapers, which are directly exposed to beam impacts. In this context, this work summarizes conceptual design studies on the new Proton Synchrotron Booster (PSB) Absorber/Scraper (PSBAS), a device aimed at cleaning the beam halo at the very early stage of the PSB acceleration. This paper outlines the steps performed to fulfill the component design requirements. It discusses thermomechanical effects as a consequence of the beam-matter collisions, simulated with the FLUKA Monte Carlo code and ANSYS finite element software; and the impedance minimization study performed to prevent beam instabilities and to reduce RF-heating on the device. INTRODUCTION The beam cleaning system (collimation and scraping) is essential for the entire CERN accelerator chain. This system absorbs unstable external beam particles, i.e. beam halos, in controlled areas preventing them from irradiating against sensitive equipment, minimizing the risk of damage [1]. In the framework of the CERN HL-LHC [2] and the LIU [3] projects, the beam intensity will be increased and the current cleaning system needs to be upgraded accordingly. In this context, Cieslak-Kowalska et al. [4] have demonstrated that the present scraping device in the PSB, the windows beam scope, will not be able to scrape the high intensity HL-LHC beams. This paper presents the conceptual design of its upgrade: the PSBAS. The PSBAS will represent the major aperture restriction of the PSB. It will scrape up to 6% of the total number of protons ( 2.95 10 [5]) for a HL-LHC beam during the very early stages of acceleration (kinetic energy per nucleon up to 200 MeV). It must be able to survive a direct accidental beam impact and its impedance (the electromagnetic resistivity at the beam transit) has to be minimized. Further, in order to correctly scrape halos the PSBAS geometry has to follow the beam transverse envelope shape (i.e. the square root of the beta function) and its longitudinal evolution inside the ∗ lorenzo.teofili@uniroma1.it device itself, [6]. To fulfill the outlined requirements the design shown in Fig. 1 was conceived. The two graphite masks, cylinders with a truncated squared based pyramid holes to follow the beam β function, are the actual beam scraper. They can be positioned in two working configurations (Fig. 1) according to the operational requirements: movable mask out provides a wide aperture for the initial beam commissioning while movable mask in limits the aperture for an optimal beam cleaning during nominal operation.

Design of the new proton synchrotron booster absorber scraper (PSBAS) in the framework of the large hadron collider injection upgrade (LIU) project