H. Vincke - Academia.edu (original) (raw)

Papers by H. Vincke

At CERN, the Super Proton Synchrotron (SPS) is equipped with a resonant slow extraction system in... more At CERN, the Super Proton Synchrotron (SPS) is equipped with a resonant slow extraction system in Long Straight Section 2 (LSS2) towards the fixed target (FT) beam lines in the North Area. The extraction region provides the physics experiments with a quasi-DC flux of high-energy protons over a few seconds, which corresponds to tens of thousands of turns. The resonant slow extraction process provokes beam losses and is therefore the origin of radiation damage and the production of induced radioactivity in this region of the machine. This induced radioactivity imposed high constraints on the equipment design to be reliable to minimise the radiation exposure to personnel during machine maintenance. A detailed FLUKA model was developed in order to better understand the beam loss patterns, activation of the machine and to identify equipment components that could be optimised to reduce the residual dose related hazards. Simulations identified multiple alternative materials for extraction ...

This paper discusses the radiation protection issues which will arise during the TI8 and the sect... more This paper discusses the radiation protection issues which will arise during the TI8 and the sector test. For both tests two main topics are discusses. The first point concentrates on assessments of the prompt radiation levels during the tests and the necessary access restrictions. The second point analyzes the consequences of the activation along the beam line and its surroundings which are caused by the beam losses at the beam line elements and the beam impact in the TED. For the sector test especially the impact for the LHCb area will be discussed in detail.

The paper describes CERN’s approach to radiation protection during LS1. It addresses the regulato... more The paper describes CERN’s approach to radiation protection during LS1. It addresses the regulatory and operational landscape before and during LS1. The lessons learnt from LS1 will be used to define the roadmap towards LS2. Despite the large amount of maintenance and repair work in all radiation areas, CERN succeeded in keeping the collective dose to personnel at a reasonable level. Moreover, CERN’s objective of keeping individual doses below 3 mSv in 2013 was largely achieved; only two experts slightly exceeded the dose objective. In addition, no radiological incident or accident had to be reported.

AWAKE, an Advanced Wakefield Experiment is launched at CERN to verify the proton driven plasma wa... more AWAKE, an Advanced Wakefield Experiment is launched at CERN to verify the proton driven plasma wakefield acceleration concept. Proton bunches at 400 GeV/c will be extracted from the CERN SPS and sent along a 750 m long proton line to a plasma cell, a Rubidium vapour source, where the proton beam drives wakefields reaching accelerating gradients of several gigavolts per meter. A high power laser pulse will copropagate within the proton bunch creating the plasma by ionizing the (initially) neutral gas. An electron beam will be injected into the plasma cell to probe the accelerating wakefield. The AWAKE experiment will be installed in the CNGS facility. First proton beam to the plasma cell is expected by end 2016. The installation planning and the baseline parameters of the experiment are shown. The design of the experimental area and the integration of the new beam-lines as well as the experimental equipment are presented. The needed modifications of the infrastructure in the facility...

arXiv: Accelerator Physics, 2011

Since November 2009, the LHC commissioning progresses very well, both with proton and lead beams.... more Since November 2009, the LHC commissioning progresses very well, both with proton and lead beams. It will continue in 2011 and nominal LHC operation is expected to be attained in 2013. In parallel, plans for various LHC upgrades are under discussion, suggesting a High-Luminosity (HL) upgrade first and a High-Energy (HE) upgrade in a later state. Whereas the upgrade in luminosity would require the modification of only some few key accelerator components like the inner triplets, the upgrade in beam energy from 7 TeV to 16.5 TeV would require the exchange of all dipoles and of numerous other accelerator components. The paper gives an overview of the radiation protection issues related to the dismantling of LHC components prior to the installation of the HE-LHC components, i.e. after about 20 years of LHC operation. Two main topics will be discussed: (i) the exposure of workers to ionizing radiation during the dismantling of dipoles, inner triplets or collimators and experiments and (ii...

Radiation Protection Dosimetry, 2013

Journal of Physics: Conference Series, 2013

Nuclear Technology, 2009

Abstract Radiation monitoring during operation of CERN’s high-energy accelerators in general, and... more Abstract Radiation monitoring during operation of CERN’s high-energy accelerators in general, and the Large Hadron Collider and its experiments in particular, poses a major challenge due to the stray radiation fields, which are characterized by a complex particle composition and a wide range of energies. In order to monitor ambient doses around workplaces and inside the machine tunnel, high-pressure ionization chambers (so-called IG5) and air-filled ionization chambers under atmospheric pressure (PMI) will be used. Because of the complexity of the radiation field, standard gamma or neutron radiation sources are not applicable to accurately calibrate monitors used in such environments. Hence, the use of Monte Carlo simulation programs like FLUKA is indispensable to obtain an appropriate monitor calibration. Following this idea the response of the aforementioned monitors to mixed particle fields ranging from thermal energies to several giga-electron-volts was simulated. Because neutrons are the main contributor to total dose at many locations around the accelerators, dedicated neutron experiments were carried out at the Research Center for Nuclear Physics, Osaka University, utilizing quasi-monoenergetic beams of 250 and 392 MeV to benchmark the simulated detector responses. Good agreement was found at 392 MeV, whereas at 250 MeV the calculations predicted considerably higher readings of the detector than the ones observed experimentally.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2016

The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plas... more The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ∼ 12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (∼ 15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 2020

We determined the distribution of activation products inside the magnet coils of a medical cyclot... more We determined the distribution of activation products inside the magnet coils of a medical cyclotron that has been operational for fifteen years. Besides FLUKA, we based our approach on new software tools (RAW and ActiWiz) developed for high-energy accelerators at CERN. A combined analysis of measurements on the coils with Monte-Carlo simulations resulted in a detailed three-dimensional radiological characterisation of the coils. Our results provide the required information for the radiation protection expert to identify the appropriate waste elimination scheme.

EPJ Web of Conferences, 2017

MedAustron is a synchrotron based accelerator facility for cancer therapy and research in Wiener ... more MedAustron is a synchrotron based accelerator facility for cancer therapy and research in Wiener Neustadt, 50 km south of Vienna. The facility will provide protons up to kinetic energies of 250 MeV and carbon ions up to 400 MeV/n for ion beam therapy. Additionally, protons up to 800 MeV kinetic energy will be used in a dedicated room for non-clinical research. In order to obtain a shielding concept for this facility a detailed geometry of the accelerator facility was implemented into the Monte-Carlo code FLUKA and shielding simulations were performed. In the course of these simulations the contributions of different particle types to the mixed fields around the accelerator and behind shielding were analysed. In an iterative process with the architect the final design of the shielding concept was developed until it was capable of reducing the effect of secondary radiation on humans and the environment below Austrian legal limits.

Journal of Physics: Conference Series, 2018

In 2011 the ActiWiz code was developed at CERN in order to optimize the choice of materials for a... more In 2011 the ActiWiz code was developed at CERN in order to optimize the choice of materials for accelerator equipment from a radiological point of view. Since then the code has been extended to allow for calculating complete nuclide inventories and provide evaluations with respect to radiotoxicity, inhalation doses, etc. Until now the software included only predefined radiation environments for CERN's high-energy proton accelerators which were based on FLUKA Monte Carlo calculations. Eventually the decision was taken to invest into a major revamping of the code. Starting with version 3 the software is not limited anymore to predefined radiation fields but within a few seconds it can also treat arbitrary environments of which fluence spectra are available. This has become possible due to the use of ~100 CPU years' worth of FLUKA Monte Carlo simulations as well as the JEFF cross-section library for neutrons < 20 MeV. Eventually the latest code version allowed for the efficient inclusion of 42 additional radiation environments of the LHC experiments as well as considerably more flexibility in view of characterizing also waste from CERN's Large Electron Positron collider (LEP). New fully integrated analysis functionalities like automatic evaluation of difficult-tomeasure nuclides, rapid assessment of the temporal evolution of quantities like radiotoxicity or dose-rates, etc. make the software a powerful tool for characterization complementary to general purpose MC codes like FLUKA. In this paper an overview of the capabilities will be given using recent examples from the domain of waste characterization as well as operational radiation protection.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009

[5] A. A. Mangiarotti Mangiarotti et al., et al., On On the deterministic the deterministic and a... more [5] A. A. Mangiarotti Mangiarotti et al., et al., On On the deterministic the deterministic and and stochastic solutions stochastic solutions of of Space Space Charge Charge models models and and their impact their impact on high on high resolution timing resolution timing, , Nucl Nucl. Phys. B. Phys. B Proc Proc. .

Proceedings of …, 2004

In preparation of the installation of a radiation monitoring system for the future LHC and its in... more In preparation of the installation of a radiation monitoring system for the future LHC and its injectors comprehensive studies were performed to evaluate the suitability of different existing monitors for radiation protection measurements in pulsed and complex, mixed radiation fields. ...

In the course of designing a radiation monitoring system for the LHC it is necessary to study the... more In the course of designing a radiation monitoring system for the LHC it is necessary to study the response functions of different monitoring devices thoroughly in order to identify suitable candidates. Among the systems currently investigated are IG5 ionisation chambers by Centronic Ltd. Generally, Monte Carlo simulations are a suitable tool to investigate the response to specific particle types over a wide energy range and also to mixed radiation fields. This note describes the simulations performed using the FLUKA particle transport code to calculate response functions for argon- and hydrogen-filled IG5 chambers with respect to various particle types at different energies. The results obtained for photons and neutrons are also compared to measurements that were performed to validate the simulation model.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2008

Neutron energy spectra were measured behind the lateral shield of the CERF (CERN-EU High Energy R... more Neutron energy spectra were measured behind the lateral shield of the CERF (CERN-EU High Energy Reference Field) facility at CERN with a 120 GeV/c positive hadron beam (a mixture of mainly protons and pions) on a cylindrical copper target (7-cm diameter by 50-cm long). An NE213 organic liquid scintillator (12.7-cm diameter by 12.7-cm long) was located at various longitudinal positions behind shields of 80-and 160-cm thick concrete and 40-cm thick iron. The measurement locations cover an angular range with respect to the beam axis between 13 and 133°. Neutron energy spectra in the energy range between 32 MeV and 380 MeV were obtained by unfolding the measured pulse height spectra with the detector response functions which have been verified in the neutron energy range up to 380 MeV in separate experiments. Since the source term and experimental geometry in this experiment are well characterized and simple and results are given in the form of energy spectra, these experimental results are very useful as benchmark data to check the accuracies of simulation codes and nuclear data. Monte Carlo simulations of the experimental set up were performed with the FLUKA, MARS and PHITS codes. Simulated spectra for the 80-cm thick concrete often agree within the experimental uncertainties. On the other hand, for the 160-cm thick concrete and iron shield differences are generally larger than the experimental uncertainties, yet within a factor of 2. Based on source term simulations, observed discrepancies among simulations of spectra outside the shield can be partially explained by differences in the high-energy hadron production in the copper target.

V. Hafych, A. Caldwell, R. Agnello, C.C. Ahdida, M. Aladi, M.C. Amoedo Goncalves, Y. Andrebe, O. ... more V. Hafych, A. Caldwell, R. Agnello, C.C. Ahdida, M. Aladi, M.C. Amoedo Goncalves, Y. Andrebe, O. Apsimon, 6 R. Apsimon, 7 A.-M. Bachmann, M.A. Baistrukov, 9 F. Batsch, M. Bergamaschi, P. Blanchard, P.N. Burrows, B. Buttenschön, J. Chappell, E. Chevallay, M. Chung, D.A. Cooke, H. Damerau, C. Davut, 14 G. Demeter, A. Dexter, 7 S. Doebert, J. Farmer, 1 A. Fasoli, V.N. Fedosseev, R. Fiorito, 5 R.A. Fonseca, 16 I. Furno, S. Gessner, 17 A.A. Gorn, 9 E. Granados, M. Granetzny, T. Graubner, O. Grulke, 20 E. Gschwendtner, E.D. Guran, J.R. Henderson, 21 M. Hüther, M.Á. Kedves, V. Khudyakov, 8 S.-Y. Kim, 3 F. Kraus, M. Krupa, T. Lefevre, L. Liang, 14 N. Lopes, K.V. Lotov, 9 S. Mazzoni, D. Medina Godoy, J.T. Moody, K. Moon, P.I. Morales Guzmán, M. Moreira, T. Nechaeva, E. Nowak, C. Pakuza, H. Panuganti, A. Pardons, A. Perera, 5 J. Pucek, A. Pukhov, B. Ráczkevi, R.L. Ramjiawan, 10 S. Rey, O. Schmitz, E. Senes, L.O. Silva, C. Stollberg, A. Sublet, A. Topaloudis, N. Torrado, P.V. Tuev, 9 M. Turner...