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Arredondo I.,ESS Bilbao | Del Campo M.,ESS Bilbao | Echevarria P.,ESS Bilbao | Jugo J.,University of the Basque Country | Etxebarria V.,University of the Basque Country
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2013

This work presents a multipurpose configurable control system which can be integrated in an EPICS control network, this functionality being configured through a XML configuration file. The core of the system is the so-called Hardware Controller which is in charge of the control hardware management, the set up and communication with the EPICS network and the data storage. The reconfigurable nature of the controller is based on a single XML file, allowing any final user to easily modify and adjust the control system to any specific requirement. The selected Java development environment ensures a multiplatform operation and large versatility, even regarding the control hardware to be controlled. Specifically, this paper, focused on fast control based on a high performance FPGA, describes also an application approach for the ESS Bilbao's Beam Position Monitoring system. The implementation of the XML configuration file and the satisfactory performance outcome achieved are presented, as well as a general description of the Multipurpose Controller itself. © 2013 Elsevier B.V.

Jugo J.,University of the Basque Country | Eguiraun M.,ESS Bilbao
Proceedings of the IEEE International Conference on Control Applications | Year: 2010

Event-based control (EBC) is growing in importance since this paradigm leads to a better integration with networked systems. Particularly due to the distributed and asynchronous inherent nature of such systems. The reported main advantage is the reduction of the control rate allowing a less saturated communication network. This fact has been proved with different EBC schemes, as using impulse control schemes within stochastic environments and different PID structures. In this work, the experimental study of an event based input-output control scheme is presented, following the sporadic control approach and implemented in a networked environment. In this scenario, noise minimizes the advantages of event-based schemes. The use of a filtering strategy minimizes its effect, restoring the reduction of the control rate. This kind of approach leads to interesting practical applications. Simulation and experimental results show the performance of the control approach under study. © 2010 IEEE.

PubMed | National Institute of Nuclear Physics, Italy and ESS Bilbao
Type: Journal Article | Journal: The Review of scientific instruments | Year: 2016

The note presents the first plasma density measurements collected by a novel microwave interferometer in a compact Electron Cyclotron Resonance Ion Sources (ECRIS). The developed K-band (18.5 26.5 GHz) microwave interferometry, based on the Frequency-Modulated Continuous-Wave method, has been able to discriminate the plasma signal from the spurious components due to the reflections at the plasma chamber walls, when working in the extreme unfavorable condition

Cortazar O.D.,University of Castilla - La Mancha | Megia-Macias A.,E.S.S. Bilbao | Vizcaino-De-Julian A.,E.S.S. Bilbao | Tarvainen O.,University of Jyväskylä | And 2 more authors.
Review of Scientific Instruments | Year: 2014

First results from an ultra-fast frame image acquisition diagnostic coupled to a 2.45 GHz microwave hydrogen discharge are presented. The plasma reactor has been modified to include a transparent doubled shielded quartz window allowing to viewing the full plasma volume. Pictures describing the breakdown process at 1 μs exposure time have been obtained for integrated visible light signal, Balmer-alpha, Balmer-beta lines, and Fulcher-band. Several different plasma emission distributions are reported. The distribution depends on the magnetic field configuration, incident microwave power, and neutral gas pressure. © 2013 AIP Publishing LLC.

Megia-Macias A.,E.S.S. Bilbao | Cortazar O.D.,E.S.S. Bilbao | Cortazar O.D.,University of Castilla - La Mancha | Vizcaino-De-Julian A.,E.S.S. Bilbao
Review of Scientific Instruments | Year: 2014

A comparative study of two microwave driver systems (preliminary and optimized) for a 2.45 GHz hydrogen Electron Cyclotron Resonance plasma generator has been conducted. The influence on plasma behavior and parameters of stationary electric field distribution in vacuum, i.e., just before breakdown, along all the microwave excitation system is analyzed. 3D simulations of resonant stationary electric field distributions, 2D simulations of external magnetic field mapping, experimental measurements of incoming and reflected power, and electron temperature and density along the plasma chamber axis have been carried out. By using these tools, an optimized set of plasma chamber and microwave coupler has been designed paying special attention to the optimization of stationary electric field value in the center of the plasma chamber. This system shows a strong stability on plasma behavior allowing a wider range of operational parameters and even sustaining low density plasma formation without external magnetic field. In addition, the optimized system shows the capability to produce values of plasma density four times higher than the preliminary as a consequence of a deeper penetration of the magnetic resonance surface in relative high electric field zone by keeping plasma stability. The increment of the amount of resonance surface embedded in the plasma under high electric field is suggested as a key factor. © 2014 AIP Publishing LLC.

Huerta-Parajon M.,ESS Bilbao | Martinez-Ballarin R.,ESS Bilbao | Abad E.,ESS Bilbao
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2015

The ESS-Bilbao proton accelerator facility has been designed fulfilling the European Spallation Source (ESS) specifications to serve as the Spanish contribution to the ESS construction. Furthermore, several applications of the ESS-Bilbao proton beam are being considered in order to contribute to the knowledge in the field of radiobiology, materials and aerospace components. Understanding of the interaction of radiation with biological systems is of vital importance as it affects important applications such as cancer treatment with ion beam therapy among others. ESS-Bilbao plans to house a facility exclusively dedicated to radiobiological experiments with protons up to 50 MeV. Beam line design, optimisation and initial calculations of flux densities and absorbed doses were undertaken using the Monte Carlo simulation package FLUKA. A proton beam with a flux density of about 106 protons/cm2 s reaches the water sample with a flat lateral distribution of the dose. The absorbed dose at the pristine Bragg peak calculated with FLUKA is 2.4 ± 0.1 Gy in 1 min of irradiation time. This value agrees with the clinically meaningful dose rates, i.e. around 2 Gy/min, used in hadrontherapy. Optimisation and validation studies in the ESS-Bilbao line for radiobiological experiments are detailed in this article. © 2014 Elsevier B.V. All rights reserved.

Cortazar O.D.,University of Castilla - La Mancha | Megia-Macias A.,E.S.S. Bilbao | Vizcaino-De-Julian A.,E.S.S. Bilbao
Review of Scientific Instruments | Year: 2012

An experimental study of temperature and density evolution during breakdown in off-resonance ECR hydrogen plasma is presented. Under square 2.45 GHz microwave excitation pulses with a frequency of 50 Hz and relative high microwave power, unexpected transient temperature peaks that reach 18 eV during 20 μs are reported at very beginning of plasma breakdown. Decays of such peaks reach final stable temperatures of 5 eV at flat top microwave excitation pulse. Evidence of interplay between incoming power and duty cycle giving different kind of plasma parameters evolutions engaged to microwave coupling times is observed. Under relative high power conditions where short microwave coupling times are recorded, high temperature peaks are measured. However, for lower incoming powers and longer coupling times, temperature evolves gradually to a higher final temperature without peaking. On the other hand, the early instant where temperature peaks are observed also suggest a possible connection with preglow processes during breakdown in ECRIS plasmas. © 2012 American Institute of Physics.

Cortazar O.D.,ESS Bilbao | Cortazar O.D.,University of Castilla - La Mancha | Megia-Macias A.,ESS Bilbao | Vizcaino-De-Julian A.,ESS Bilbao
Review of Scientific Instruments | Year: 2013

Time resolved electron temperature and density measurements during the decay stage in a hydrogen electron cyclotron resonance (ECR) plasma are presented for a resonance and off-resonance magnetic field configurations. The measurements are conducted on a ECR plasma generator excited at 2.45 GHz denominated test-bench for ion-sources plasma studies at ESS Bilbao. The plasma parameters evolution is studied by Langmuir probe diagnostic with synchronized sample technique developed for repetitive pulsed plasmas with a temporal resolution of 200 ns in typical decay processes of about 40 μs. An afterglow transient is clearly observed in the reflected microwave power signal from the plasma. Simultaneously, the electron temperature evolution shows rebounding peaks that may be related to the interplay between density drop and microwave coupling with deep impact on the Electron Energy Distribution Function. The correlation of such structures with the plasma absorbed power and the coupling quality is also reported. © 2013 AIP Publishing LLC.

Some parts of austenitic stainless steels structures which must operate with radiofrequency in ultra high vacuum need to be machined with very high precision and need to have a copper plating treatment. The heat treatment for stress relief due to machining proposed by the major research centres is performed by vacuum furnaces, that do not damage the structure of the material, but these ovens are very complex and unusual, especially for large pieces. To facilitate this process and reduce its cost is proposed to realize in common furnaces of inert atmosphere. But it is necessary to perform the tests of intergranular corrosion susceptibility and adhesion of copper, to validate the change of the process.

Kaftoosian A.,ESS Bilbao | Gonzalez P.J.,ESS Bilbao
IPAC 2014: Proceedings of the 5th International Particle Accelerator Conference | Year: 2014

Design and development of a 30 kW, 352 MHz pulsed RF solid-state power amplifier to be utilized for feeding re-bunching cavities in proton linac, is in progress at ESSBilbao. This modular transmitter is based on in-phase combination of compact, water-cooled 2 kW RF power modules, each one consists of two combined LDMOS transistors in balanced configuration. The modules include individual bias control, measurement and supply circuits. Gate modulation is foreseen to increase efficiency in pulsed regime that is up to 3ms RF pulse width and 10% duty cycle. The 2 kW RF power module has been developed and the test results are discussed. Copyright © 2014 CC-BY-3.0 and by the respective authors.

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