Beam loss monitoring with unfolding techniques

AbstractSince the first particle accelerator’s construction in 1931, an exponential spread of these machines occurred worldwide, in different kinds of applications. Nowadays, these are mainly used for industrial (60%) and medical (35%) purposes and for scientific research (5%). High energy secondary mixed fields produced by the particle beams interaction with matter imply a complex environmental dosimetry and special radiation protection regulations able to guarantee workers and population safety. In the medical field, this aspect is particularly emphasized in hadrontherapy centres, where high energy charged particles such as protons and carbon ions modify environmental doses, with a significant increase in the neutron contribution. This work proposes a technique to identify points of losses of the primary particle beam around an acceleration ring and has been developed within the radiation protection section at the National Centre for Oncological Hadrontherapy situated in Pavia. In the first part, the radiation field produced by protons and carbon ions interactions with structural materials at different energies was investigated. The main instrument of analysis is the Monte Carlo code for particle transport FLUKA, supported by experimental measurements in the treatment room carried out with the rem counter LUPIN, designed for pulsed neutron fields dosimetry. This first step allowed an analysis of both the angular and energetic instrumental response and a comparison of experimental results with simulations. The second part proposes a description of the technique for beam loss positions reconstruction around the acceleration ring at CNAO based on the application of unfolding codes.

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Ionization Dosimetry Principles for Conventional and Laser-Driven Clinical Particle Beams

International Journal of Women’s Health Care ◽

10.33140/ijwhc/03/02/00004 ◽

2018 ◽

Vol 3 (2) ◽

Keyword(s):

Ionizing Radiation ◽

Heavy Particle ◽

Absorbed Dose ◽

High Energy ◽

Particle Energy ◽

Particle Accelerators ◽

Carbon Ions ◽

Particle Beams ◽

Radiation Fields ◽

Number Of Particles

In this paper after mentioning the clinical radiation fields of 20 keV-450 MeV/u, they are characterized by the number of particles and their energy. Particle energy is the quantity that determines radiation penetration at the depth at which the tumor is situated (Fig. 1). The number of particles (or beam intensity) is the second major quantity that assures the administration of the absorbed dose in the tumor. The first application shows the radiation levels planned for various radiation fields. Prior to interacting with the medium, the intensity (or energy fluence rate) allows the determination of energy density, energy, power and relativistic force. In the interaction process, it determines the absorbed dose, kerma and exposure. Non-ionizing radiations in the EM spectrum are used as negative energy waves to accelerate particles charged into special installations called particle accelerators. The particles extracted from the accelerator are the source of the corpuscular radiation for high-energy radiotherapy. Of these, light particle beams (electrons and photons) for radiotherapy are generated by betatron, linac, microtron, and synchrotron and heavy particle beams (protons and heavy ions) are generated by cyclotron, isochronous cyclotron, synchro-cyclotron and synchrotron. The ionization dosimetry method used is the ionization chamber for both indirectly ionizing radiation (photons and neutrons) and for directly ionizing radiation (electrons, protons and carbon ions). Because the necessary energies for hadrons therapy are relatively high, 50-250 MeV for protons and 100-450 MeV/u for carbon ions, the alternative to replace non-ionizing radiation with relativistic laser radiation for generating clinical corpuscular radiation through radiation pressure acceleration mechanism (RPA) is presented.

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Beam Hazards and Ionising Radiation

Safety for Particle Accelerators - Particle Acceleration and Detection ◽

10.1007/978-3-030-57031-6_3 ◽

2020 ◽

pp. 55-82

Author(s):

Thomas Otto

Keyword(s):

Charged Particle ◽

Radiation Protection ◽

Radiation Dosimetry ◽

Ionising Radiation ◽

Material Damage ◽

Electronic Components ◽

Particle Beams ◽

Beam Loss ◽

Charged Particle Beams ◽

Radiation Material

AbstractThis chapter treats hazards originating from particle beams. The interaction of charged particle beams with matter is described. Beam loss can cause material damage in structural and electronic components. Ionising radiation is introduced by a description of the different types of radiation. Then, the sources of ionising radiation at accelerators are defined: beam loss is the origin of prompt ionising radiation. Material activated by the passage of particle cascades is a long-lived source of ionising radiation. The chapter is closed with a description of radiation dosimetry and radiation protection at accelerators.

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Heavy-ion radiography facility at the Institute of Modern Physics

Laser and Particle Beams ◽

10.1017/s0263034614000676 ◽

2014 ◽

Vol 32 (4) ◽

pp. 651-655 ◽

Cited By ~ 6

Author(s):

Lina Sheng ◽

Yongtao Zhao ◽

Guojun Yang ◽

Tao Wei ◽

Xiaoguo Jiang ◽

...

Keyword(s):

Image Plane ◽

Heavy Ion ◽

High Energy ◽

Experimental Result ◽

Monte Carlo Code ◽

Carbon Ions ◽

Proton Radiography ◽

Magnetic Lens ◽

Modern Physics ◽

Pass Through

AbstractIn order to identify the density and material type, high energy protons, electrons, and heavy ions are used to radiograph dense objects. The particles pass through the object, undergo multiple coulomb scattering, and are focused onto an image plane by a magnetic lens system. A modified beam line at the Institute of Modern Physics of the Chinese Academy of Sciences has been developed for heavy-ion radiography. It can radiograph a static object with a spatial resolution of about 65 µm (1 σ). This paper presents the heavy-ion radiography facility at the Institute of Modern Physics, including the beam optics, the simulation of radiography by Monte Carlo code and the experimental result with 600 MeV/u carbon ions. In addition, dedicated beam lines for proton radiography which are planned are also introduced.

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Neural networks to identify particles using topological properties of calorimeters

Sba Controle & Automação Sociedade Brasileira de Automatica ◽

10.1590/s0103-17592004000100008 ◽

2004 ◽

Vol 15 (1) ◽

pp. 62-70

Author(s):

Denis Oliveira Damazio ◽

José Manoel de Seixas

Keyword(s):

Particle Beam ◽

High Energy ◽

Generation Process ◽

Topological Properties ◽

Energy Particle ◽

Particle Beams ◽

Classifier System ◽

Topological Mapping ◽

Classifier Performance ◽

Online Implementation

The present work describes a neural particle classifier system based on topological mapping of the segmented information provided by a high-energy calorimeter, a detector that measures the energy of incoming particles. The achieved classification efficiencies are above 97.50% for the higher energy particle beams, even when experimental data exhibit unavoidable contamination due to the particle beam generation process, what could jeopardize the classifier performance. Some deterioration in the performance for the lower energy range is also discussed. The reduction on the dimensionality of the data input space caused by the topological mapping may be very helpful when online implementation of the classifier is required.

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Light emission from particle beam induced plasma: An overview

Laser and Particle Beams ◽

10.1017/s0263034611000838 ◽

2012 ◽

Vol 30 (2) ◽

pp. 199-205 ◽

Cited By ~ 10

Author(s):

Andreas Ulrich

Keyword(s):

Light Emission ◽

Ion Beam ◽

Particle Beam ◽

Heavy Ion ◽

High Energy ◽

Light Sources ◽

Particle Beams ◽

Excimer Molecules ◽

First Results ◽

Low Energy Electron

AbstractExperiments to study the light emission from plasma produced by particle beams are presented. Fundamental aspects in comparison with discharge plasma formation are discussed. It is shown that the formation of excimer molecules is an important process. This paper summarizes various studies of particle beam induced light emission and presents the first results of a direct comparison of light emission induced by electron- and ion beam excitation. Both high energy heavy ion beam and low energy electron beam experiments are described and an overview over applications in the form of light sources, lasers, and ionization devices is given.

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High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

Nanoscale Research Letters ◽

10.1186/s11671-020-03433-7 ◽

2020 ◽

Vol 15 (1) ◽

Author(s):

Vladimir Yu. Osipov ◽

Fedor M. Shakhov ◽

Kirill V. Bogdanov ◽

Kazuyuki Takai ◽

Takuya Hayashi ◽

...

Keyword(s):

Polycrystalline Diamond ◽

Particle Beam ◽

Production Method ◽

High Energy ◽

Nitrogen Vacancy ◽

High Energy Particle ◽

Paramagnetic Resonance ◽

Precursor Material ◽

Mean Size ◽

Characteristic Features

Abstract We demonstrate a high-pressure, high-temperature sintering technique to form nitrogen-vacancy-nitrogen centres in nanodiamonds. Polycrystalline diamond nanoparticle precursors, with mean size of 25 nm, are produced by the shock wave from an explosion. These nanoparticles are sintered in the presence of ethanol, at a pressure of 7 GPa and temperature of 1300 °C, to produce substantially larger (3–4 times) diamond crystallites. The recorded spectral properties demonstrate the improved crystalline quality. The types of defects present are also observed to change; the characteristic spectral features of nitrogen-vacancy and silicon-vacancy centres present for the precursor material disappear. Two new characteristic features appear: (1) paramagnetic substitutional nitrogen (P1 centres with spin ½) with an electron paramagnetic resonance characteristic triplet hyperfine structure due to the I = 1 magnetic moment of the nitrogen nuclear spin and (2) the green spectral photoluminescence signature of the nitrogen-vacancy-nitrogen centres. This production method is a strong alternative to conventional high-energy particle beam irradiation. It can be used to easily produce purely green fluorescing nanodiamonds with advantageous properties for optical biolabelling applications.

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Synchronized Periodic Solutions of a Class of Periodically Driven Nonlinear Oscillators

Journal of Applied Mechanics ◽

10.1115/1.3125856 ◽

1988 ◽

Vol 55 (3) ◽

pp. 721-728 ◽

Cited By ~ 9

Author(s):

Gamal M. Mahmoud ◽

Tassos Bountis

Keyword(s):

Periodic Solutions ◽

Periodic Orbits ◽

Nonlinear Oscillators ◽

High Energy ◽

Second Order ◽

Multiple Time ◽

Particle Beams ◽

Periodically Driven ◽

Time Scaling ◽

A New Technique

We consider a class of parametrically driven nonlinear oscillators: x¨ + k1x + k2f(x,x˙)P(Ωt) = 0, P(Ωt + 2π) = P(Ωt)(*) which can be used to describe, e.g., a pendulum with vibrating length, or the displacements of colliding particle beams in high energy accelerators. Here we study numerically and analytically the subharmonic periodic solutions of (*), with frequency 1/m ≅ √k1, m = 1, 2, 3,…. In the cases of f(x,x˙) = x3 and f(x,x˙) = x4, with P(Ωt) = cost, all of these so called synchronized periodic orbits are obtained numerically, by a new technique, which we refer to here as the indicatrix method. The theory of generalized averaging is then applied to derive highly accurate expressions for these orbits, valid to the second order in k2. Finally, these analytical results are used, together with the perturbation methods of multiple time scaling, to obtain second order expressions for regions of instability of synchronized periodic orbits in the k1, k2 plane, which agree very well with the results of numerical experiments.

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Vertically Integrated Amorphous Silicon Particle Sensors

MRS Proceedings ◽

10.1557/proc-808-a10.7 ◽

2004 ◽

Vol 808 ◽

Cited By ~ 5

Author(s):

N. Wyrsch ◽

C. Miazza ◽

S. Dunand ◽

A. Shah ◽

D. Moraes ◽

...

Keyword(s):

Amorphous Silicon ◽

Material Properties ◽

Dark Current ◽

Silicon Particle ◽

Particle Beam ◽

High Energy ◽

Beta Particle ◽

Particle Detection ◽

Glass Substrates ◽

Hydrogenated Amorphous

ABSTRACTVertically integrated particle sensors have been developed using thin-film on ASIC technology. Hydrogenated amorphous silicon n-i-p diodes have been optimized for particle detection. These devices were first deposited on glass substrates to optimize the material properties and the dark current of very thick diodes (with thickness up to 50 m). Corresponding diodes were later directly deposited on two types of CMOS readout chips. These vertically integrated particle sensors were tested in beta particle beam from 63Ni and 90Sr sources. Detection of single low- and high- energy beta particle was achieved.

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