PRESENT STATUS AND PROGRESSES OF RFQ OF IFMIF/EVEDA

Abstract The IFMIF project aims to produce an intense neutron flux (14.4 MeV) to test and qualify materials suitable for the construction of fusion power plants. The DEMO project will be the first plant for civil and industrial power production. The neutron flux is obtained by impacting two 125 mA deuteron beams, produced by two parallel LINACs, onto a liquid Lithium target. We are working on the engineering validation phase of the project (IFMIF-EVEDA) The RFQ of IFMIF/EVEDA is composed of 18 modules flanged together for a total length of 9.8 m designed to accelerate the 125 mA D+ beam from 0.1 MeV to 5 MeV at a frequency of 175 MH

Fission Target Design

The report describes the technical concepts and the main parameters adopted for the first design for the fission target of the multi-MW Target Station of EURISOL. Starting from the dimensions of liquid neutron converter as defined by Baseline Design, eight fission target containers were disposed around the converter and closely coupled to eight ion-sources. Two versions of design are presented , proposing different solutions at all levels: target geometry, heating resistance, thermal expansion compensation, supporting in the view of remote handling, type of ion source, current and high voltage powering scheme, cooling and others. At this stage of design many details are skipped, while the dimensions of different components are not yet the result of mechanical/electrical/thermal calculations

FISSION TARGET DESIGN AND INTEGRATION OF NEUTRON CONVERTER FOR EURISOL-DS PROJECT

A study of a new fission target for EURISOL-DS is presented with a detailed description of the target. Calculations of several configurations were done using Monte Carlo code FLUKA aimed to obtaining 1015 fissions/s on single target. In Eurisol, neutrons inducing the fission reactions are produced by a proton beam 1GeV-4mA interacting with a mercury converter. The target configuration was customized to gain fission yield from the large amount of low energy neutrons produced by the Hg converter. To this purpose, the fissile material is composed by discs of 238-Uranium carbide enriched with 15 g of 235-U. Studies of several geometries were done in order to define the shape and composition of uranium target, taking into account the mechanical and space constraint

EURISOL Fission Target Design adapting MAFF concept

The first two version of design as described in “Fission Target Design” report available on Task 4 pages on EURISOL web-site (http://www.eurisol.org), integrating a number of eight fission targets and ion sources around the multiMW Hg target inside one large vacuum vessel, have raised several concerns about the viability of the concept. Following the decision of EURISOL-DS Management Board, the adaptation of solutions proposed for MAFF project was studied from different points of view within tasks 2-4. In the present report, the new engineering design coming out form these studies is described and discussed

Improved Design of EURISOL Fission Target Systems and Handling

The report discusses the constraints, solutions and options for integration of the main systems needed to assure the operation and maintenance/exchange of the fission target – ion sources assemblies capable to withstand very high neutron fluxes around EURISOL multi-MW neutron converter, to provide the desired fission rate of 10e15 fis./sec. and to extract with highest possible efficiencies the fission products as radioactive ion beam. Adapting the concepts developed for a single fission target within PIAFE and MAFF projects, simultaneous operation of six fission targets was proposed for EURISOL. A first design following these concepts was presented in a previous report. Here we describe several improvements implemented in the design for a more efficient, more reliable and safer operation. An optimized layout of the part of the EURISOL MMW station related to fission target services and handling is proposed as well

Measurement of the Response Time of the Delay Window for the Neutron Converter of the SPIRAL2 Project

Research and development of a safety system for the SPIRAL2 facility has been conceived to protect the UCx target from a possible interaction with the 200 kW deuteron beam. The system called "delay window" (DW) is designed as an integral part of the neutron converter module and is located in between the neutron converter and the fission target. The device has been designed as a barrier, located directly behind the neutron converter on the axis of the deuteron beam, with the purpose of "delaying" the eventual interaction of the deuteron beam with the UCx target in case of a failure of the neutron converter. The "delay" must be long enough to allow the interlock to react and safely stop the beam operation, before the beam will reach the UCx target. The working concept of the DW is based on the principle of the electrical fuse. Electrically insulated wires placed on the surface of a Tantalum disk assure a so called "free contact", normally closed to an electronic circuit located on the HV platform, far from the radioactive environment. The melting temperature of the wires is much less than Tantalum. Once the beam is impinging on the disk, one or more wires are melted and the "free contact" is open. A solid state relay is changing its state and a signal is sent to the interlock device. A prototype of the DW has been constructed and tested with an electron beam of power density equivalent to the SPIRAL2 beam. The measured "delay" is 682.5 ms (σ=116 ms), that is rather long in comparison to the intrinsic delays introduced by the detectors itself (2 ms) and by the associated electronic devices (120 ns). The experimental results confirm that, in the case of a failure of the neutron converter, the DW as conceived is enable to withstand the beam power for a period of time sufficiently long to safely shut down the SPIRAL2 accelerator

Photonuclear spectroscopy with the ELIADE array at ELI-NP

The Extreme Light Infrastructure - Nuclear Physics in Bucharest-Magurele, Romania, is a major European undertaking with the aim of constructing a facility that can produce the worlds highest intensity laser beams as well as unique high-brilliance, narrow-bandwidth gamma-ray beams using laser-based inverse Compton scattering. One of the main instruments being constructed for the nuclear physics and applications with high-brilliance gamma-beams research activity is the ELIADE detector array of eight segmented HPGe clover detectors. Using the nuclear resonance fluorescence technique this setup will provide us with access to several nuclear observables like spins, parities, level widths, and branching ratios in the decay. From these observables we expect to draw conclusions about, for example, nuclear dipole response, properties of pygmy resonance and collective scissors mode excitations, parity violation in nuclear excitations, and matrix elements for neutrinoless double-beta decay, among other topics. The uniqueness of the environment in which ELIADE will operate presents several challenges in the design and construction of the array. In this contribution we will present some of these challenges and how these challenges are overcome

NUCLEAR RESONANCE FLUORESCENCE EXPERIMENTS AT ELI-NP

The development at ELI-NP of a new laser-based Inverse Compton Scattering gamma beam system, featuring extremely high intensities at very narrow bandwidths, opens new and important opportunities in nuclear science research. Nuclear photonics is undergoing a revival, the gamma beams with unprecedented features delivered at ELI-NP paving the way for high accuracy and detailed nuclear physics studies. A wide range of industrial, homeland security and healthcare applications will also experience an important boost. The combination of nuclear photonics with the technique of Nuclear Resonance Fluorescence (NRF) allows for the recovery of several physical quantities characterizing the excited nuclear states in a completely model independent way. These observables include the excitation energies, level widths, gamma decay branching ratios, spin quantum numbers, and parities. In the last decade, the NRF technique allowed for the discovery and detailed study of various phenomena in atomic nuclei. Examples are the collective magnetic dipole Scissors Mode in deformed nuclei, quadrupole excitations with mixed proton neutron symmetry, the electric Pygmy Dipole Resonance, octupole coupled excitations, or alpha-cluster states. The present Technical Design Report (TDR) deals with the application of the NRF technique at ELI-NP to study forefront nuclear structure research topics. The document presents some of the physics cases to be investigated and discusses the feasibility of the proposed experiments. The advanced characteristics of the gamma beams available at ELI-NP and the use of high efficiency detection systems will offer a powerful combination, unique in the world, for the investigation of the proposed physics cases. The main detection system for the NRF studies is a multi-detector array (ELIADE - ELI-NP Array of DEtectors) based on the use of composite high-purity Ge detectors and large volume LaBr3 scintillator detectors able to detect with high efficiency gamma rays with energies up to several MeV in the presence of the high radiation background produced by the gamma beams. Gamma-ray energies and angular distributions will be measured with high accuracy. The design of the array is made highly flexible to allow for an easy transposition in different locations in the high- and low-energy gamma beam areas, a fast change of configuration based on the needs of the experiments, the use of the detectors in other setups and easy maintenance to reduce the downtimes. NRF measurements will be possible starting from early stages of the Gamma Beam System operation at ELI-NP with both low- and high-energy gamma beams. Already in the initial phase of operation at low-energies below 3.5 MeV the gamma beams at ELI-NP will be competitive with the present state-of-the-art gamma beam systems