Design and analysis of a RFQ resonant cavity for the IFMIF project

The IFMIF RFQ is designed with very challenging specifications to accelerate a 125mA deuterons beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz, consists of 18 modules with length of ~550 mm each. The total lenght is 9.78 m. During the three years of PhD the candidate was involved on different aspects, from the mechanical design to the quality control on the production process. Chapter 1 presents a general overview of the IFMIF project and the scientific context. On chapter 2 the design of the cooling system of the modules of the accelerator will be described, with the development of thermal-structural and fluid-thermal-structural numerical analyses. Chapters 3 and 4 will describe the development of an in-house technology for the vertical brazing and the fixation tooling, by means a strict collaboration of the section of Padova of INFN and the LNL. The developments of 1D and 3D FE analyses for the prediction of the thermal brazing cycle will be described. Moreover, the improvements on the control (visual and ultrasonic inspection) of the brazed joints and the feedbacks to the mechanical design will be presented. Chapter 5 will describe the various phases of the production of the modules of the RFQ with the most important mechanical design aspects. The production of the IFMIF EVEDA RFQ accelerator is a quite challenging task due to the narrow tolerance of the pieces that should be guarantee also after some thermal treatments for the brazing. The focus will be in particular to the quality control of the single elements and the entire modules during the production: -The dimensional quality control, prevalently by CMM with active scanning probe. -The quality assurance of the brazed joints by visual and the ultrasonic inspection. Their influence for the design choices and the solution of eventual problem will be described

Status of the RFQ linac installation and conditioning of the Linear IFMIF Prototype Accelerator

Abstract The Radio Frequency Quadrupole (RFQ) linac and 1.6 MW RF power system of the Linear IFMIF Prototype Accelerator (LIPAc) facility in the International Fusion Energy Research Center (IFERC) in Rokkasho (Japan) has been installed and conditioned. During the assembly and tuning process, the RFQ cavity was protected with a temporary tent from the potential deterioration of performance caused by dust. The vacuum in the cavity was improved through the 100 °C baking process of the cavity. The high power test of the 175 MHz RF systems up to 200 kW in CW for each of the eight RF chains was performed for checking its stable output reproducibility in Japan, before connecting 9–3/16 inch coaxial transmission lines from the RF chains to the RF input couplers of the cavity. It was confirmed that the eight RF chains provided the balanced RF power to the single RFQ cavity in-phase using a feedback loop and a synchronization system. The peak power in the cavity achieved 150 kW in the pulsed mode, which corresponds approximately to the required electric field to accelerate proton beam. Such RF conditioning process is ongoing to achieve 600 kW approximately required for deuteron beam commissioning planned in 2018

Design and analysis of a RFQ resonant cavity for the IFMIF project

The IFMIF RFQ is designed with very challenging specifications to accelerate a 125mA deuterons beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz, consists of 18 modules with length of ~550 mm each. The total lenght is 9.78 m. During the three years of PhD the candidate was involved on different aspects, from the mechanical design to the quality control on the production process. Chapter 1 presents a general overview of the IFMIF project and the scientific context. On chapter 2 the design of the cooling system of the modules of the accelerator will be described, with the development of thermal-structural and fluid-thermal-structural numerical analyses. Chapters 3 and 4 will describe the development of an in-house technology for the vertical brazing and the fixation tooling, by means a strict collaboration of the section of Padova of INFN and the LNL. The developments of 1D and 3D FE analyses for the prediction of the thermal brazing cycle will be described. Moreover, the improvements on the control (visual and ultrasonic inspection) of the brazed joints and the feedbacks to the mechanical design will be presented. Chapter 5 will describe the various phases of the production of the modules of the RFQ with the most important mechanical design aspects. The production of the IFMIF EVEDA RFQ accelerator is a quite challenging task due to the narrow tolerance of the pieces that should be guarantee also after some thermal treatments for the brazing. The focus will be in particular to the quality control of the single elements and the entire modules during the production: -The dimensional quality control, prevalently by CMM with active scanning probe. -The quality assurance of the brazed joints by visual and the ultrasonic inspection. Their influence for the design choices and the solution of eventual problem will be described.L'RFQ di IFMIF e un acceleratore progettato per accelerare un fascio di deuteroni a 125 mA da 0.1 MeV a 5 MeV ad una frequenza di 175 MHz. E composto da 18 moduli per una lunghezza totale di 9.8 m. In questo lavoro di tesi il candidato si è occupato di diversi aspetti, dalla progettazione meccanica della cavità al controllo qualità del processo produttivo. Il capitolo 1 fornisce una presentazione generale del progetto IFMIF e del contesto scientifico ad esso legato. Il capitolo 2 presenta in dettaglio gli aspetti della progettazione del sistema di raffreddamento dei moduli della linea acceleratrice, attraverso simulazioni numeriche termostrutturale e fluido termo strutturali. Nei capitoli 3 e 4 è descritto lo sviluppo di una propria tecnologia per la brasatura verticale dell’attrezzatura di brasatura attraverso una stretta collaborazione tra l’INFN di Padova per la progettazione e i laboratori INFN di Legnaro per la realizzazione. Inoltre lo sviluppo di strumenti per il calcolo dei cicli termici di brasatura tramite analisi monodimensionali e tridimensionali tramite codici agli elementi finiti è descritto. Lo sviluppo di metodologie per il controllo dei giunti brasati e la loro influenza sulle scelte progettuali saranno presentati. Il capitolo 5 fornisce un quadro delle varie fasi della produzione dei moduli della cavità. La produzione dei moduli dell'RFQ di IFMIF richiede lo sviluppo di soluzioni tecnologiche per le strette tolleranze geometriche che devono essere garantite anche dopo diversi trattamenti termici di brasatura. L’attenzione è stata focalizzata soprattutto sul controllo qualità dei singoli elementi e dei moduli completi nel processo produttivo: -Il controllo dimensionale prevalentemente tramite CMM dotata di testa a scansione attiva. -Il controllo delle brasature tramite ispezione visiva e l’utilizzo della tecnica degli ultrasuoni. La loro influenza sulle scelte progettuali e la soluzione di eventuali problemi saranno descritte

A neutron-induced Single Event Effects facility at the 70 MeV cyclotron of LNL-INFN

AbstractWe describe a proposed neutron irradiation facility for studyi ng neutron-i nduced Single Event Effects (SEE) in microelectronic components and systems at the new variable energy high current proton cyclotron (35-70 MeV; 750μA) soon to be operational at LNL. We descri be the progress in designing two neutron production targets to furnish continuous atmospheric-like neutron differential spectra: a W-based thick target (to stop 70 MeV protons), and an innovative composite target made of Beryllium and Tantal um or Lead. We also describe the layout of the facility that will also house quasi-monoenergetic neutron (QMN) and direct proton beam lines. The thick target beam line could be available as soon as the new cyclotron is commissioned. The composite target and QMN beam lines, to be designed in concert, would be completed soon after

Beam Dynamics of the First Beams for IFMIF-EVEDA RFQ Commissioning

International audienceThe installation of the IFMIF-EVEDA RFQ, MEBT, LEBT, source and beam dump was completed in September 2017. The beam dynamics of the first beams for the IFMIF-EVEDA RFQ commissioning is presented. Moreover, a proposal for the CW RFQ steady state commissioning is shown, with a focus on the beam dynamics challenges of the beam transport after the RFQ