Electron-hadron colliders are the ultimate tool for high-precision quantum chromodynamics studies and provide the ultimate microscope for probing the internal structure of hadrons. The electron is an ideal probe of the proton structure because it provides the unmatched precision of the electromagnetic interaction, as the virtual photon or vector bosons probe the proton structure in a clean environment, the kinematics of which is uniquely determined by the electron beam and the scattered lepton, or the hadronic final state accounting appropriately for radiation. The Hadron Electron Ring Accelerator HERA (DESY, Hamburg, Germany) was the only electron-hadron collider ever operated (1991–2007) and advanced the knowledge of quantum chromodynamics and the proton structure, with implications for the physics studied in RHIC (BNL, Upton, NY) and the LHC (CERN, Geneva, Switzerland). Recent technological advances in the field of particle accelerators pave the way to realize next-generation electron-hadron colliders that deliver higher luminosity and enable collisions in a much broader range of energies and beam types than HERA. Electron-hadron colliders combine challenges from both electron and hadron machines besides facing their own distinct challenges derived from their intrinsic asymmetry. This review paper will discuss the major features and milestones of HERA and will examine the electron-hadron collider designs of the Electron-Ion Collider (EIC) currently under construction at BNL, the CERN’s Large Hadron electron Collider (LHeC), at an advanced stage of design and awaiting approval, and the Future Circular lepton-hadron Collider (FCC-eh).

/pdf/electron-hadron-colliders-eic-lhec-and-fcc-eh-3ijymuai.pdf

Electron-Hadron Colliders: EIC, LHeC and FCC-eh

The Crab Cavities (CCs) may induce emittance growth, driven by phase and amplitude jitter, and lead to a degradation of the High Luminosity LHC (HL-LHC) beam. Furthermore, the tight HL-LHC space constraints call for non-axially symmetric cavity designs that come with higher order non-linearities which can affect the long-term dynamic aperture (DA). In order to study the effect the CCs have on the beam and the engineering challenges to validate the pre-series design, a prototype HL-LHC CC set was installed in the SPS machine in the year-end technical stop (YETS) of 2017-2018, and the first ever CC tests with protons were performed in 2018. This note is a collection of the reports and work done on the emittance growth measurements prior [1–4] and after [5] the CC installation, as well as simulations [6] and measurements [7] performed to study the CC and SPS nonlinearities effect. Finally, a summary of the instrumentation observations of the SPS CC experimental measurements [8] is presented.

/pdf/deliverable-2-7-analysis-of-the-existing-sources-of-blow-up-puth2dntw2.pdf

Deliverable 2.7: Analysis of the existing sources of blow-up in the SPS by experiments and estimation/measurement of the effect of the crab cavities in the SPS

In this paper, we present the effects of linear transverse-longitudinal coupling on beam size at the interaction point (IP) of a collider with a local crab crossing scheme, when time-dependent transverse deflection (crab kicks) and dispersive orbit intertwine near IP. The analytic propagation formula and the closed orbit form of the crab dispersion and momentum dispersion are derived. The nonzero momentum dispersion at crab cavities and the nonideal phase from crab cavities to IP are detailed with the derived propagation formula to predict the beam size distortion at IP with or without the beam-beam interaction. The linear results are compared with nonlinear simulation using the weak-strong beam-beam code. 

Combined effects of crab dispersion and momentum dispersion in colliders with local crab crossing scheme

CERN1. Challenges for the existing LHC Accelerating System (ACS)Superconducting cavities were introduced at CERN to boost the energy of the Large Electron Positron (LEP) collider and first prototypes of 4cell 352 MHz cavities for LEP2 were produced in 1991.At that time and due to the relatively low frequency, copper cavities sputtered with a thin film of Niobium were shown to provide a reliable performance at the required gradients, and hence was an economical option compared to bulk Niobium.Other benefits include thermal stability due to the large copper substrate and insensitivity to stray magnetic fields.Hence, this technology was adopted to construct 288 cavities for LEP2.For the LHC, a proton machine with significantly lower synchrotron radiation losses per turn, the need for accelerating voltage is greatly reduced and therefore the LEP technology was adapted "as-is" without trying to push cavity performance.Furthermore the technology proved to be reliable and stable during LEP operation.The first LHC module with four single-cell 400.79 MHz cavities was successfully tested in 2000 and all four modules were installed and commissioned with beam by 2008 [Linnecar (2008))], in time for the LHC start-up.LHC cavities Two cryomodules per beam are in operation (see Fig. 1).The cavities are connected with large aperture beam tubes (300 mm) to reduce the longitudinal impedance and thereby transient beam loading. 

Radio Frequency systems

In the Electron-Ion Collider (EIC) design, to avoid vertical orbit bumps in the Electron Storage Ring (ESR) at some crossing points with Hadron Storage Ring (HSR) to preserve the electron polarization, we plan to tilt the ESR plane by 200 μrad with an axis connecting IP6 and IP8. In this article, we study the beam-beam interaction when two rings are not in the same plane. The Lorentz boost formula is derived and the required vertical crabbing strength is calculated to compensate the dynamic effect. The beam-beam simulations are performed to validate the theory.

Beam-beam interaction for tilted storage rings

Many future particle colliders require beam crabbing to recover geometric luminosity loss from the nonzero crossing angle at the interaction point (IP). A first demonstration experiment of crabbing with hadron beams was successfully carried out with high energy protons. This breakthrough result is fundamental to achieve the physics goals of the high luminosity LHC (HL-LHC) and the future circular collider (FCC). The expected peak luminosity gain (related to collision rate) is 65% for HL-LHC and even greater for the FCC. Novel beam physics experiments with proton beams in CERN's Super Proton Synchrotron (SPS) were performed to demonstrate several critical aspects for the operation of crab cavities in the future HL-LHC including transparency with a pair of cavities, a full characterization of the cavity impedance with high beam currents, controlled emittance growth from crab cavity induced rf noise. © 2021 American Physical Society. All rights reserved.

First demonstration of the use of crab cavities on hadron beams

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

L. Arnaudon

Author Tools

Chat about Author

Papers

First demonstration of the use of crab cavities on hadron beams