Beam Loss Monitoring for LHC Machine Protection

Holzer, Eva Barbara; Dehning, B.; Effnger, Ewald; Emery, Jonathan D.; Grishin, V.; Hajdú, C.; Jackson, Stephen; Kurfuerst, C; Marsili, A.; Misiowiec, M.; Nagel, Markus; Busto, Eduardo; Nordt, Annika; Roderick, C; Sapinski, Mariusz; Zamantzas, Christos

doi:10.1016/j.phpro.2012.04.110

Cited by 18 publications

(15 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The detection of potentially dangerous losses using beam loss monitors (BLM) [45] is one of the most important observables for machine-protection purposes. A depleted halo could jeopardise the performance of the current machine-protection strategy.…”

Section: Main Hel Constraints and Requirementsmentioning

confidence: 99%

Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

et al. 2021

View full text Add to dashboard Cite

The design stored beam energy in the CERN high-luminosity large hadron collider (HL-LHC) upgrade is about 700 MJ, with about 36 MJ in the beam tails, according to estimates based on scaling considerations from measurements at the LHC. Such a large amount of stored energy in the beam tails poses serious challenges on its control and safe disposal. In particular, orbit jitters can cause significant losses on primary collimators, which can lead to accidental beam dumps, magnet quenches, or even permanent damage to collimators and other accelerator elements. Thus, active control of the diffusion speed of halo particles is necessary and the use of hollow electron lenses (HELs) represents the most promising approach to handle overpopulated tails at the HL-LHC. HEL is a very powerful and advanced tool that can be used for controlled depletion of beam tails, thus enhancing the performance of beam halo collimation. For these reasons, HELs have been recently included in the HL-LHC baseline. In this paper, we present detailed beam dynamics calculations performed with the goal of defining HEL specifications and operational scenarios for HL-LHC. The prospects for effective halo control in HL-LHC are presented.

show abstract

Section: Main Hel Constraints and Requirementsmentioning

confidence: 99%

Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Both measurements produce very characteristic distributions of losses versus crystal angle and collimator position, described in the following, that only occurs if channeling is present. Local losses were measured using the standard Beam Loss Monitoring (BLM) system of the LHC [16] based on ionization chambers. The LHC BLM system is ideal for these measurements because it has a good sensitivity and each monitor is capable to measure losses as small as 10 −7 Gy/s.…”

Section: Experimental Procedures and Beam Conditionsmentioning

confidence: 99%

First observation of ion beam channeling in bent crystals at multi-TeV energies

et al. 2021

View full text Add to dashboard Cite

Planar channeling in bent crystals has been observed in LHC with multi-TeV proton beam in 2015. Two crystals, mounted on novel high-accuracy goniometers (one in the horizontal and one in the vertical plane), are integrated in the LHC collimation system, for studying the feasibility of the crystal-based collimation scheme. Using this experimental setup, tests with fully-stripped lead ion beams at both 450 Z and 6500 Z GeV were carried during dedicated LHC beam time. Planar channeling was observed for the first time with lead ions at these unprecedented energies surpassing by more than 1 order of magnitude the previous state-of-the-art for lead heavy ions and providing an important experimental basis for future applications of bent crystals in beam manipulations. The set of measurements performed to confirm this observation, as the local loss reduction in presence of channeling and the evidence of a deflected beam downstream of the crystal, are presented.

show abstract

“…Mainly two systems are used for active radiation monitoring in the LHC. [7]: The beam loss monitor (BLM) system has been developed as a part of the LHC machine protection infrastructure. Its aim is to prevent damage to machine components and magnet quenches due to beam losses.…”

Section: Radiation Monitoring In the Lhcmentioning

confidence: 99%

Radiation Environment in the LHC Arc Sections During Run 2 and Future HL-LHC Operations

Biłko

Castro

Brügger

et al. 2020

IEEE Trans. Nucl. Sci.

View full text Add to dashboard Cite

The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) is the largest accelerator in the world, spanning a circumference of 26.7 km. During its operation, small fractions of the beams are being continuously lost. This leads to mixed-field radiation that might affect electronic equipment through both cumulative and single-event effects. This article considers the radiation environment during Run 2 (years 2015-2018) in the LHC arc sectors that constitute approximately 70% of the accelerator, housing a huge amount of electronics. There, the main magnets' configuration is periodic, and the main contributor to losses is the interaction of the beams with residual gas molecules, resulting in relatively low-radiation levels, as opposed to different parts of the LHC. However, as presented, there are locations where losses are no longer dominated by residual gas. In these locations, radiation levels are higher by up to more than two orders of magnitude and could, therefore, be problematic in terms of cumulative radiation effects on electronics. In this article, the dose measurements from beam loss monitors have been combined with the FLUKA simulation for the arc sectors in order to indirectly retrieve the residual gas densities and radiation profile under the magnet cryostats, at the equipment level, for the losses caused by residual gas. Estimations for the radiation levels in the arc sectors during the high-luminosity LHC era and potential implications for the electronics are discussed as well.

show abstract

Beam Loss Monitoring for LHC Machine Protection

Cited by 18 publications

References 1 publication

Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

First observation of ion beam channeling in bent crystals at multi-TeV energies

Radiation Environment in the LHC Arc Sections During Run 2 and Future HL-LHC Operations

Contact Info

Product

Resources

About