This paper provides an overview of the final design and fabrication status of the IFMIF cryomodule, including the design issues, and deals with the strategies implemented in order to mitigate the main technical and logistical risks identified. The seismic constraints as well as licensing requirements, transportation issue and assembly process are also addressed. The IFMIF cryomodule presented here will be part of the Linear IFMIF Prototype Accelerator (LIPAc) whose construction is ongoing [1, 2]. It is a full scale prototype of one of the IFMIF accelerators, from the injector to the first cryomodule, aiming at validating the technical options for the future accelerator-based D-Li neutron source to produce high intensity high energy neutron flux for testing of candidate materials for use in fusion energy reactors. The cryomodule contains all the equipment to transport and accelerate a 125 mA deuteron beam from an input energy of 5 MeV up to 9 MeV. It consists of a horizontal cryostat of about 6 m long, 3 m high and 2 m wide, which includes 8 superconducting HWRs for beam acceleration working at 175 MHz and at 4.5 K, 8 power couplers to provide RF power to cavities, and 8 Solenoid Packages as focusing elements. OVERVIEW OF THE IFMIF LIPAC PROJECT The International Fusion Materials Irradiation Facility (IFMIF) aims at producing intense neutron fluxes so as to characterize materials envisioned for future fusion reactors. To this end, two identical Linacs, each accelerating a continuous-wave 125-mA deuteron beam at the final energy of 40 MeV, would be necessary to produce by break-up interactions of the D beam with the Li target the required 10 neutrons per seconds with the appropriate energy [3]. Because the accelerators have to reach unprecedented performances, the feasibility is being tested through the design, manufacturing, installation, commissioning and testing activities of a 1:1-scale prototype accelerator from the injector to the first cryomodule referred to as the Linear IFMIF Prototype Accelerator (LIPAc) shown in Figure 1. The IFMIF project is carried out under the framework of the Broader Approach Agreement between Europe and Japan. It is presently in its Engineering Validation and Engineering Design Activities (EVEDA), and the accomplishment in summer 2013, on schedule, of its Engineering Design Activities (EDA) allowed the successful development of the IFMIF Intermediate Engineering Design Report (IIEDR) [4]. The EU contributions to the LIPAc accelerator (CEASaclay, CIEMAT, INFN Legnaro and SCK-CEN Mol) are coordinated by the Fusion for Energy organization. The D injector and LEBT have been installed and are nowadays being tested on the Rokkasho site (JAEA) in Japan. Figure 1: IFMIF LIPAc accelerator.

Technical and Logistical Challenges for IFMIF-LIPAC Cryomodule Construction

The Linear IFMIF Prototype Accelerator (LIPAc), which is presently under design and realization, aims to accelerate a 125 mA deuteron beam up to 9 MeV. Therefore, a low-beta 175 MHz Half-Wave Resonator (HWR) was initially designed and manufactured with a tuning system based on a capacitive plunger located in the electric field region. Following the results of the vertical tests at 4.2K, this tuning system was abandoned and replaced by a conservative solution based on the HWR wall deformation using an external mechanical tuner. This paper will focus on the manufacturing of the prototype cavity, the studies realized to explain the first test results and the solutions taken to overcome the difficulties, leading to the validation of the prototype. Then, we will present the new cavity design.

Cavity Development for the Linear IFMIF Prototype Accelerator

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), a superconducting option has been chosen for the 5 MeV RF Linac of the engineering validation phase of the project (LIPAc), based on a cryomodule composed of 8 half-wave resonators (HWR), 8 RF couplers and 8 solenoid packages. The latest developments of the SRF Linac are presented in [1]. This paper will focus on the beam vacuum of the cryomodule. The cryomodule beam line is made of the pattern solenoid package / cavity-coupler, and a valve on each side of the cryomodule. During the installation of the cryomodule on the accelerator system, the cavity string has to be pumped down with the beam valves closed. Thereby a manifold is connected to the cavities during the assembly of the beam line components in the clean room. In previous conferences, the cryomodule was presented with a vacuum manifold connected to each cavity [2]. A study realized on this complex vacuum configuration with Molflow, a test-particle Monte-Carlo simulator for ultrahigh vacuum systems, permitted to reduce the number of cavities connected to the manifold and by consequence to reduce the risk of pollution during the clean room assembly.

VACUUM STUDY OF THE CAVITY STRING FOR THE IFMIF - LIPAc CRYOMODULE

Tuner systems for accelerating cavities are required to compensate static and dynamic frequency perturbations during beam operation. In the case of superconducting cavities, these are commonly tuned by deforming the cavity wall in specific places of the geometry. Nevertheless, considering the mechanical properties and frequency versus displacement sensitivity of some structures, tuning by deformation doesn’t allow meeting the requirements. In these specific cases, inspired from the “room temperature technology”, an alternative tuning technique by insertion of a helium-cooled superconducting plunger can be considered and has been studied for several projects (IFMIF, ESS-BILBAO). Advantages and drawbacks of such solution will be discussed and the successful results on SPIRAL2 cryomodule developed at IPNO will be presented.

A Cold Tuner System With Mobile Plunger

The IFMIF accelerator aims to provide an acceleratorbased D-Li neutron source to produce high intensity high energy neutron flux for testing of candidate materials for use in fusion energy reactors. The first phase of the project, called EVEDA (Engineering Validation and Engineering Design Activities) aims at validating the technical options by constructing an accelerator prototype, called LIPAc (Linear IFMIF Prototype Accelerator) whose construction has begun [1], [2]. It is a full scale of one of the IFMIF accelerator from the injector to the first cryomodule. The cryomodule contains all the necessary equipment to transport and accelerate a 125 mA deuteron beam from an input energy of 5 MeV up to output energy of 9 MeV. It consists of a horizontal vacuum tank approximately 6 m long, 3 m high and 2.0 m wide, and includes 8 superconducting HWRs working at 175 MHz and at 4.45 K for beam acceleration. 8 Power Couplers provide RF power to the cavities up to 70 kW CW in the LIPAc case and 200 kW CW in the IFMIF case, with 8 Solenoid Packages acting as focusing elements. This paper gives an overview of the progress, achievements and status of the IFMIF SRF LINAC.

Design and Manufacturing Status of the IFMIF-LIPAC SRF LINAC

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV in CW, a Linear IFMIF Prototype Accelerator (LIPAc), is presently under design and realization for the first phase of the project [1]. This accelerator prototype includes a Superconducting RadioFrequency Linac (SRF Linac), which is designed for the transportation and focalization of the deuteron beam up to 9 MeV. This SRF Linac is a large cryomodule of ~6 m long, working at 4.4 K and at the frequency of 175 MHz in continuous wave. It is mainly composed of 8 low-beta Half-Wave Resonators (HWR), 8 Solenoid Packages and 8 RF Power Couplers. This paper focuses on the recent developments and changes made on the SRF Linac design: following the abandon of the HWR frequency tuning system, initially based on a plunger located inside the central region of the resonator, a new external tuning system has been designed, implying a complete redesign of the resonator and consequently impacting the cryomodule lattice. The recent changes in the design are presented in this paper. In addition, cold tests were performed on a HWR prototype and cold tests results of the magnets prototypes are also presented.

https://epaper.kek.jp/ipac2013/papers/thpfi004.pdf

Progress on the srf linac developments for the ifmif- lipac project

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

J. Neyret

Author Tools

Chat about Author

Papers

Progress on the srf linac developments for the ifmif- lipac project