Electron cloud observations with the Vacuum Pilot Sector - Quentin Duong // The beam screen test bench experiment (BESTEX) and results of recent sample measurements - Peter Henriksen // New conflat chain design - Roberto Prieto Garcia

Tuesday 20 Feb 2024, 10:30 → 12:00 Europe/Zurich

30/7-018 - Kjell Johnsen Auditorium (CERN)

Quentin DUONG, Peter Lindquist Henriksen (CERN), Roberto Prieto Garcia (CERN), Quentin Duong (Université Paris-Saclay (FR))

10:30 → 10:50 Electron cloud observations with the Vacuum Pilot Sector

Abstract:
Recent and future high-energy storage rings operate at high-luminosity, resulting from closely spaced and intense particle bunches collisions. The successive bunch passages and its interaction with the beam pipe lead to the formation of an electron cloud that may be an hard limit for machine operation if left uncontrolled.
The Vacuum Pilot Sector, installed in the LHC ring, allows to study the beam interactions with diverse type of materials: copper, TiZrV alloy both LHC materials, and amorphous carbon coated copper, HL-LHC base line material.
This presentation focuses on electron and pressure responses to two different filling scheme during run 2023, for a bulk and amorphous carbon coated copper materials.
Electron currents and pressures are higher in the bulk copper station than in the amorphous carbon one, and the hybrid filling scheme (mix of 8b4e and 36b) offers an advantage on the 72b one in terms of electron-cloud build-up.
Moreover, first measurements tend to show that the electron energy distribution is not affected by the beam energy increase while the energy gained by accelerated electrons decreases with the protons per bunch parameter.

Speaker: Mr Quentin DUONG

2024_VSC_Seminar_ResultsVPS_DUONG.pdf

2024_VSC_Seminar_ResultsVPS_DUONG.pptx

10:50 → 11:10 The beam screen test bench experiment (BESTEX) and results of recent sample measurements

The vacuum requirements for future accelerators such as FCC-hh, make it necessary to study the materials used for the beam screen in a representative synchrotron radiation environment, to evaluate the resulting photon-stimulated desorption.
This presentation gives an overview of the beam screen test bench experiment (BESTEX) at the KARA synchrotron and how simulations are used to aid in the processing of data. Beam screen prototypes manufactured for BESTEX measurements are presented, and preliminary results and implications of the measured photon-stimulated desorption are discussed.

Speaker: Peter Lindquist Henriksen (CERN)

BESTEX_seminar_2024_02.pdf

BESTEX_seminar_2024_02.pptx

11:10 → 11:30 New conflat chain design

‘’The Quick ConFlat (QCF) connection shows the further development of existing CF flange join system. The employment of QCF chain clamps ensures a quicker, easier and less space-demanding assembly compared with standard bolted CF flanges. The design approach of new QCF chain clamps with an angle of 15° and its experimental validation procedure is presented’’.

Speaker: Roberto Prieto Garcia (CERN)

2024_02_20_VSC_Seminar_Roberto_Prieto_Garcia.pdf

2024_02_20_VSC_Seminar_Roberto_Prieto_Garcia.pptx