This document collects the proceedings of the "Parton Radiation and Fragmentation from LHC to FCC-ee" workshop (http://indico.cern.ch/e/ee jets16) held at CERN in Nov. 2016. The writeup reviews the latest theoretical and experimental developments on parton radiation and parton-hadron fragmentation studies -including analyses of LEP, B-factories, and LHC data-with a focus on the future perspectives reacheable in e + e − measurements at the Future Circular Collider (FCC-ee), with multi-ab −1 integrated luminosities yielding 10 12 and 10 8 jets from Z and W bosons decays as well as 10 5 gluon jets from Higgs boson decays. The main topics discussed are: (i) parton radiation and parton-to-hadron fragmentation functions (splitting functions at NNLO, small-z NNLL resummations, global FF fits including Monte Carlo (MC) and neural-network analyses of the latest Belle/BaBar high-precision data, parton shower MC generators), (ii) jet properties (quark-gluon discrimination, e + e − event shapes and multi-jet rates at NNLO+N n LL, jet broadening and angularities, jet substructure at small-radius, jet charge determination, e + e − jet reconstruction algorithms), (iii) heavy-quark jets (dead cone effect, charm-bottom separation, gluon-to-bb splitting); and (iv) non-perturbative QCD phenomena (colour reconnection, baryon and strangeness production, Bose-Einstein and Fermi-Dirac final-state correlations, colour string dynamics: spin effects, helix hadronization).
The feasibility study for Nano-Infiltration and Transient Eutectic phase process SiC/SiC (NITE SiC/SiC)NITE SiC/SiC as a potential novel target material for pions/muons production at high-power proton accelerators facilities is in progress. Compared with graphite that is the principal target material for pions/muons production, higher transport efficiency and higher oxidation resistance can be expected. However, the residual radiation dose of NITE SiC/SiC is 400 times higher than that of graphite a year after the irradiation. To validate the simulation, the residual radionuclides of the irradiated samples have been analyzed by gamma-ray spectroscopy. To understand the thermal shock behavior, NITE-SiC/SiC was included in the HRMT35 experiment at CERN's HiRadMat facility. In these studies, NITE SiC/SiC is proved to be a promising material for pions/muons production with the higher transport efficiency and the oxidation resistance, though the maintenance scenario has to be carefully designed due to higher residual radiation dose. The thermal shock resistance and proton-irradiation resistance of NITE SiC/SiC will be confirmed to be applied for the pions/muons production.
Beam Intercepting Devices (BIDs) are essential protection elements for the operation of the Large Hadron Collider (LHC) complex. The LHC internal beam dump (LHC Target Dump Injection or LHC TDI) is the main protection BID of the LHC injection system; its main function is to protect LHC equipment in the event of a malfunction of the injection kicker magnets during beam transfer from the SPS to the LHC. Several issues with the TDI were encountered during LHC operation, most of them due to outgassing from its core components induced by electron cloud effects, which led to limitations of the injector intensity and hence had an impact on LHC availability. The absorbing cores of the TDIs, and of beam intercepting devices in general, need to deal with high thermo-mechanical loads induced by the high intensity particle beams. In addition, devices such as the TDI — where the absorbing materials are installed close to the beam, are important contributors to the accelerator impedance budget. To reduce impedance, the absorbing materials that make up the core must be typically coated with high electrical conductivity metals. Beam impact testing of the coated absorbers is a crucial element of development work to ensure their correct operation. In the work covered by this paper, the behaviour of several metal-coated absorber materials was investigated when exposed to high intensity and high energy proton beams in the HiRadMat facility at CERN. Different coating configurations based on copper and molybdenum, and absorbing materials such as isostatic graphite, Carbon Fibre Composite (CfC) and Silicon Carbide reinforced with Silicon Carbide fibres (SiC-SiC), were tested in the facility to assess the TDI's performance and to extract information for other BIDs using these materials. In addition to beam impact tests and an extensive Post Irradiation Examination (PIE) campaign to assess the performance of the coatings and the structural integrity of the substrates, extensive numerical simulations were carried out.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.