Conveners
Vacuum in Accelerators
- Kun Liu (Northeastern University)
Vacuum in Accelerators: 2
- Mauro Taborelli (CERN)
Vacuum in Accelerators: 2
- Mauro Taborelli (CERN)
Vacuum in Accelerators: 3
- Reza Valizadeh (Science and Technology Facilities Council (STFC/DL/ASTeC) Daresbury Laboratory Accelerator Science and Technology Centre)
Vacuum in Accelerators: 3
- Reza Valizadeh (Science and Technology Facilities Council (STFC/DL/ASTeC) Daresbury Laboratory Accelerator Science and Technology Centre)
Modern particle accelerators introduced have more and more demanding specifications to the beam vacuum chambers. From one side, the specified vacuum level is often not only UHV but even XHV, from another side, the cross sectional sizes of beam vacuum chamber are getting smaller and smaller, down to as little as 5 mm. In addition, this can also be complicated by another specification: short...
The main parameters of vacuum systems for heavy ion cyclotron complexes are determined by means of computer programs GENAP and VACLOS that were developed and tested on the basis of experiments on four heavy ion cyclotrons of the FLNR. They estimate ion beam losses based on both the numerical simulation of pressure distribution in vacuum chambers practically of any arbitrary geometry and...
Amorphous carbon(a-C) thin films with low Secondary Electron Yield (SEY) are the baseline solution to mitigate the electron multipacting phenomenon in the beam screens of some critical superconducting magnets of the High Luminosity Large Hadron Collider (HL-LHC). Many of these magnets are already installed in the accelerator ring and the a-C coating has to be done ‘in-situ’. We present the...
The electron cloud phenomenon is currently one of the main limitations to the operation of high intensity positively charged particle accelerators as the LHC. The Secondary Electron Yield (SEY) of the inner surface of the beam vacuum chamber steers the multiplication of primary electrons produced by both synchrotron radiation and ionization of residual gases. For several materials used in...
J-PARC 3 GeV rapid cycling synchrotron (RCS) is one of the highest beam power proton accelerator, which accelerates 8.3 x 10^13 protons at 25 Hz up to 3 GeV, corresponding 1 MW beam power. Challenges for achieving low pressure region of ultrahigh vacuum (UHV) less than 10^-5 Pa in RCS beam line are the following outgassing source.
1. Outgassing from large surface area of beam pipes and other...
The European XFEL is a 3.4 km long branched underground facility that generates extremely intense X-ray flashes to be used by researchers from all over the world. Located in the Hamburg urban area, it officially began operation in September 2017, and the first experiments are running as scheduled since then. Located at the soft X-ray beamline (SASE3), a gas-based intensity modulation cell is...
In future nuclear fusion reactors, the erosion by hydrogenic charge-exchange neutrals will strictly affect the lifetime of the recessed elements of the first wall [1]. Among the possible candidates for these components, reduced activation ferritic martensitic (RAFM) steels, such as Eurofer-97, containing small amounts of high-Z elements like tungsten (W), are a valuable economical and...
A new generation of ultra-high vacuum (UHV) coupling systems for particle accelerators are currently under investigation at CERN [1,2]. In such systems, the unique thermal recovery features of shape memory alloys (SMAs) are exploited. In particular, thanks to the large strain and stress recovery capabilities of SMAs, ring shaped couplers, to be used as beam-pipe connectors, are being...
In terms of the increasing complexity of fundamental research topics at accelerators the requirements concerning the experimental setup of these large vacuum machines gain more and more impact. One crucial aspect to fulfil these experimental requirements is the necessity of monitoring and capturing the process parameters of the accelerator itself, like temperature or position of vacuum...
On the way to High Luminosity LHC the electron cloud build-up has been identified as the main limiting factor. It has been shown that this phenomenon correlates with the secondary electron (SE) yield of the materials used to construct accelerator’s vacuum chambers. To this day, different methods have been developed in order to mitigate the electron multiplication process. Currently, there are...
The electron storage ring of the Swiss Light Source (SLS) is supposed to be exchanged for a new one following the principle of a multibend achromat lattice (MBA). The objective is to shrink the horizontal emittance of the electron beam by a factor forty. All vacuum chambers have to be exchanged for chambers with a much smaller cross section to fit into the numerous strong magnets. In order to...
The SwissFEL facility will have two undulator lines. The one for hard X-rays, with wavelengths of 7 Å (2keV) to 1 Å (12.4 keV), with an electron energy of 5.8 GeV, is named Aramis. The second one, covering the entire soft X-ray range, from about 200 eV to 2 keV with full polarisation control, is named Athos.
Compared to the in-vacuum Aramis-undulators (U15), the Athos-undulators will have a...
CERN has a long experience in the conception, construction and exploitation of particle accelerators for high-energy physics. CERN accelerator complex consists of several installations facing different challenges concerning radiation activation, damage, contamination, etc. determined by the energy and type of beam: protons, heavy ions, radioactive ion beams, neutrons, etc.
This contribution...
In the framework of the EuroCirCol(*) collaboration (work package 4 “Cryogenic Beam Vacuum System”), the fabrication of 3 FCC-hh beam-screen (BS) prototypes has been carried out, with the aim of testing them at room temperature on the KARA (previously known as ANKA) 2.5 GeV light source at Karlsruhe Institute of Technology. The 3 BS prototypes are going to be tested one after the other on a...
The FAIR (Facility for Antiproton and Ion Research) accelerator complex is under construction at the GSI campus in Darmstadt in Germany. It consists of about 4 km of beam vacuum system, where the vacuum requirements are different for almost all machines. While in the fast ramped SIS100 one has to deal with cryogenic and room temperature operated sections with static vacuum pressure in the...
In 2018 the SLAC vacuum laboratory will prepare, test, particle free clean and assemble all the components of LCLS-II beamline. This presentation will go through the manufacturing process and the quality checks adopted at SLAC to meet the LCLS-II UHV requirements. In addition an overview of the new facilities and procedures put in place to clean and assemble the Particle Free beamline regions...
