Thermal Issues for the Optical Transition Radiation Screen for the ELI-NP Compton Gamma Source (original) (raw)

Thermal Simulations for Optical Transition Radiation Screen for ELI-NP Compton Gamma Source

2017

The ELI-NP GBS (Extreme Light Infrastructure-Nuclear Physics Gamma Beam Source) is a high brightness electron LINAC that is being built in Romania. The goal for this facility is to provide high luminosity gamma beam through Compton Backscattering. A train of 32 bunches at 100Hz with a nominal charge of 250pC is accelerated up to 740 MeV. Two interaction points with an IR Laser beam produces the gamma beam at different energies. In order to measure the electron beam spot size and the beam properties along the train, the OTR screens must sustain the thermal and mechanical stress due to the energy deposited by the bunches. This paper is an ANSYS study of the issues due to the high quantity of energy transferred to the OTR screen. They will be shown different analysis, steady-state and thermal transient analysis, where the input loads will be the internal heat generation equivalent to the average power, deposited by the ELI-GBS beam in 512 ns, that is the train duration. Each analyses w...

For the Optical Transition Radiation Screens for the Eli-NP Compton Gamma Source

2016

A high brightness electron Linac is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32, 16 ns spaced, bunches with a nominal charge of 250 pC will collide with the laser beam in the interaction point. Electron beam spot size is measured with optical transition radiation proile monitors. In order to measure the beam properties along the train, the screens must sustain the thermal stress due to the energy deposited by the bunches; moreover the optical radiation detecting system must have the necessary accuracy and resolution. This paper deals with the analytical studies as well as numerical simulations to investigate the thermal behavior of the screens impinged by the nominal bunch.

Beam Energy Measurements With a Optical Transition Radiation for the ELI-NP Compton Gamma Source

2018

A high brightness electron LINAC is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with the laser beam in the interaction point at two electron beam energies, namely 280 MeV and 720 MeV. Electron beam spot size is measured with optical transition radiation (OTR) profile monitors. The paper deals with the possibility of using the OTR monitors to measure also beam energy along the machine; such measurements may help monitoring the accelerating sections performances, especially when the whole bunch train is being accelerated. We discuss the measurement principle, the expected accuracy and the main characteristic of the optical line to retrieve the angular distribution of the emitted radiation.

Design of the Diagnostic Stations for the ELI-NP Compton Gamma Source

2018

A high brightness electron Linac is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with the laser beam in the interaction point. Electron beam spot size is measured with optical transition radiation (OTR) profile monitors. Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine. This will be useful, for instance, during the commissioning phase of the GBS in order to verify the correct functionality of the C-Band accelerating structures, due to the fact that there are OTR screens after each accelerating module. This paper deals with the studies of different optic configurations to achieve the field of view, resolution and accuracy in order to measur...

Technology Developments for ELI-NP Gamma Beam System

2019

The ELI-NP gamma beam system (GBS) is a linac based gamma-source in construction in Magurele (RO) by the European consortium EuroGammaS led by INFN. Photons with tunable energy, from 0.2 to 19.5 MeV, and with intensity and brilliance beyond the state of the art, will be produced by Compton back-scattering between a high quality electron beam (up to 740 MeV) and an intense laser pulse at 100 Hz repetition rate. Production of very intense photon flux with narrow bandwidth requires multi-bunch operation and laser recirculation at the interaction point. In this paper, the main technological developments carried out by the EuroGammaS consortium for the generation of the ELI-NP gamma beam will be described with a special emphasis on the electron linac technology, such as: RF-gun and C-band accelerating structures design fabrication and tests; low level RF (LLRF) and synchronization systems specifications and development. Finally, the laser recirculation apparatus design is briefly describ...

Technical Design Report EuroGammaS proposal for the ELI-NP Gamma beam System

2014

The machine described in this document is an advanced Source of up to 20 MeV Gamma Rays based on Compton back-scattering, i.e. collision of an intense high power laser beam and a high brightness electron beam with maximum kinetic energy of about 720 MeV. Fully equipped with collimation and characterization systems, in order to generate, form and fully measure the physical characteristics of the produced Gamma Ray beam. The quality, i.e. phase space density, of the two colliding beams will be such that the emitted Gamma ray beam is characterized by energy tunability, spectral density, bandwidth, polarization, divergence and brilliance compatible with the requested performances of the ELI-NP user facility, to be built in Romania as the Nuclear Physics oriented Pillar of the European Extreme Light Infrastructure. This document illustrates the Technical Design finally produced by the EuroGammaS Collaboration, after a thorough investigation of the machine expected performances within the...

ELI-NP Gamma Beam System - Current Project Status

2019

The Gamma Beam System at the ELI-NP (Extreme Light Infrastructure – Nuclear Physics) under construction in Bucharest-Magurele, Romania, aims at producing high brilliance gamma-rays, based on the laser Compton backscattering, up to 3.5 and 19.5 MeV out of two interaction chambers. The design of a warm radio frequency linac is optimized to meet a unique source specification i.e. high brilliance, small relative bandwidth, tunable energy, and high spectral density. Together with the technological development in the field of high energy/high quality lasers it will open new opportunities for nuclear physics research in fields like nuclear photonics, nuclear astrophysics, photofission, and production of exotic nuclei, applications in industry, medicine, and space science. The S-band laser driven RF gun and two accelerating sections constitute the injector. Then the beam is accelerated by C-band linac up to 350 and 720 MeV. The GBS was designed and is being constructed by the EuroGammaS Ass...

Gamma beam industrial applications at ELI-NP

International Journal of Modern Physics: Conference Series, 2016

The Nuclear Physics oriented pillar of the pan-European Extreme Light Infrastructure (ELI-NP) will host an ultra-bright, energy tunable, and quasi-monochromatic gamma-ray beam system in the range of 0.2–19.5 MeV produced by laser Compton backscattering. This gamma beam satisfies the criteria for large-size product investigations with added capabilities like isotope detection through the use of nuclear resonance fluorescence (NRF) and is ideal for non-destructive testing applications. Two major applications of gamma beams are being envisaged at ELI-NP: industrial applications based on NRF and industrial radiography and tomography. Both applications exploit the unique characteristics of the gamma beam to deliver new opportunities for the industry. Here, we present the experimental setups proposed at ELI-NP and discuss their performance based on analytical calculations and GEANT4 numerical simulations. One of the main advantages of using the gamma beam at ELI-NP for applications based ...

Electron Linac design to drive bright Compton back-scattering gamma-ray sources

Journal of Applied Physics, 2013

The technological development in the field of high brightness linear accelerators and high energy/high quality lasers enables today designing high brilliance Compton-X and Gamma-photon beams suitable for a wide range of applications in the innovative field of nuclear photonics. The challenging requirements of this kind of source comprise: tunable energy (1–20 MeV), very narrow bandwidth (0.3%), and high spectral density (104 photons/s/eV). We present here a study focused on the design and the optimization of an electron Linac aimed to meet the source specifications of the European Extreme Light Infrastructure—Nuclear Physics project, currently funded and seeking for an innovative machine design in order to outperform state-of-the-art facilities. We show that the phase space density of the electron beam, at the collision point against the laser pulse, is the main quality factor characterizing the Linac.

A gamma beam profile imager for ELI-NP Gamma Beam System

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2018

The Gamma Beam System of ELI-Nuclear Physics is a high brilliance monochromatic gamma source based on the inverse Compton interaction between an intense high power laser and a bright electron beam with tunable energy. The source, currently being assembled in Magurele (Romania), is designed to provide a beam with tunable average energy ranging from 0.2 to 19.5 MeV, rms energy bandwidth down to 0.5% and flux of about 10 8 photons/s. The system includes a set of detectors for the diagnostic and complete characterization of the gamma beam. To evaluate the spatial distribution of the beam a gamma beam profile imager is required. For this purpose, a detector based on a scintillator target coupled to a CCD camera was designed and a prototype was tested at INFN-Ferrara laboratories. A set of analytical calculations and Monte Carlo simulations were carried out to optimize the imager design and evaluate the performance expected with ELI-NP gamma beam. In this work the design of the imager is described in detail, as well as the simulation tools used and the results obtained. The simulation parameters were tuned and cross-checked with the experimental measurements carried out on the assembled prototype using the beam from an x-ray tube. 1. Introduction 1 ELI-Nuclear Physics (NP), currently being built in Magurele, Roma-2 nia, is one of the three pillars of ELI (Extreme Light Infrastructures) 3 European Project [1,2]. This facility will host the Gamma Beam System 4 (GBS), an intense and monochromatic gamma source based on inverse 5 Compton interaction between a high power laser and a high brightness 6 electron beam produced by a warm LINAC. In 2014, EuroGammaS asso-7 ciation, composed by many European research institutes and companies, 8 leaded by INFN, won a tender to provide the design, manufacturing, 9 installation and commissioning of ELI-NP-GBS [3-5]. The gamma beam 10 is expected to feature energy ranging from 0.2 to 19.5 MeV, 0.5% rms 11 bandwidth, flux of about 10 8 collimated photons/s and unprecedented