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Technical preparatory work and demonstration of principle for a high power target station for production of beams of fission fragments using the mercury proton-to-neutron converter-target and cooling technology in collaboration with the communities working on the spallation neutron sources, accelerator driven systems and the neutrino factories.
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Internal Task note
Development of the EURISOL Multi-Megawatt Target Station (2005-2009): Executive Summary
Karel Samec et al. (CERN, IPUL, ITN and PSI)
Advances in nano-technology, bio-technology, nuclear medicine and the fundamental sciences require a facility to continue improving current capabilities in Europe beyond the year 2010. European competitiveness could benefit greatly from a unique research facility, flexible enough to satisfy users from many different fields of science and technology. The facility would be a valuable asset enabling economies of scale and giving Europe access to cutting-edge technology at the heart of future technological advances of major economic importance. Specialised facilities already operating at full capacity such as SINQ in Switzerland, ILL in France, have demonstrated the benefits of bringing together users from different scientific backgrounds and different countries. Such a research policy may be reinforced by the improved performance and greater reach of the EURISOL project which is aimed at a larger research community. Beneficiaries include the medical sciences such as oncology, medical imagery or studies of protein, as well as physics, astrophysics and cosmology, not forgetting nano-technology, supra-conductivity and general material technology.
An initial Design Study funded by the European FP6 research framework program was able to establish the case for the project on a well-founded scientific and technical basis in terms of user cost-benefit analysis, risk identification and mitigation. Two major risk items were identified early on in the EURISOL program: the proton beam LINAC driver and the Multi-Megawatt target station. The current summary addresses the latter task which was assigned to a project group headed by CERN in Geneva and comprising PSI in Switzerland for the liquid metal converter target development, INFN in Italy for the fission targets and IPUL in Latvia for essential liquid metal technology testing.
Deliverable D5: The Multi-Megawatt Target Station (Final Report)
Karel Samec et al. (CERN, IPUL, ITN, PSI)
The Eurisol initiative seeks to develop an isotope production facility to provide the scientific community with the means to achieving high yields of isotopes and extending the variety of isotopes thus produced towards more exotic types rarely seen in existing facilities.
The Multi-MW converter target at the heart of the projected facility is designed to create isotopes by fissioning uranium carbide (UC) target arranged coaxially around a 4 MW converter target. It is therefore essential that the target be as compact as possible to avoid losing neutrons to capture whilst maximising the neutron flux to enhance the number of fissions per second in the UC targets.
The proposed ISOL facility would use both (a) several 100 kW proton beams on a thick solid target to produce
RIBs directly, and (b) a liquid metal 4 MW ‘converter’ target to release high fluxes of spallation neutrons which would then produce RIBs by fission in a secondary uranium carbide (UCx) target. An alternative windowless liquid mercury-jet ‘converter’ target to generate the neutrons has also been proposed for this Multi-MW target station.
EURISOL-DS Multi‐MW Target: Radiological Protection, Radiation Safety and Shielding Aspects
Y. Romanets and R. Luís (ITN)
The objective of this work was to carry out a detailed study and analysis of all aspects related to
radioprotection and radiation safety of the spallation target area and the whole spaces reserved
for the fission targets and spallation target maintenance. Operational and no‐operational
conditions were considered for an evaluation of the radiation safety conditions.
An analysis of the proposed shielding dimensions and configuration was performed for the
system during operation time. Parameters as activation, dose rate, energy deposition, etc. are
more important for the no‐operation period, in order to evaluate the hazard level and
determine the staff access type to the maintenance areas (direct or remote control).
Such elements as the fission targets and the whole structure involved on it were studied in more
detail because of the disposal issues, after operation. Activation, dose rate and residual nuclides
were studied for each element of the assembly. All parameters were analyzed according to their
time evolution after the shutdown of the facility.
The studies were carried out using the state‐of‐the‐art Monte Carlo programs FLUKA and
MCNPX.
EURISOL-DS Overall Design of the Multi-MW Target Station
Olivier Choisnet, Cyril Kharoua, Yacine Kadi, Karel Samec (CERN)
The EURISOL Design Study investigated the feasibility of a complex instrument to push back the boundaries of current physics knowledge amidst today’s ever-increasing need for realism due to constraints imposed by safety, performance and, not least, budgetary responsibility.
In order to attend to these concerns, the EURISOL Multi-Megawatt converter target, its associated fission targets and the three 100 kW direct targets are all integrated into a single facility housing the ancillary equipment as well. The overall layout of the facility, its functional break-down and the main modes of operation are presented in the current report.
EURISOL-DS Multi-Megawatt Target: Remote Handling Equipment
Cyril Kharoua, Olivier Choisnet, Yacine Kadi, Karel Samec (CERN)
The design proposed within Task #2 of the EURISOL Design Study for the remote handling of the mercury converter target and its associated loop is presented with particular emphasis on achieving rapid turn-around during routine maintenance.
The converter target needs to be completely exchanged every four months due to the high irradiation damage sustained. Other components are less susceptible to damage but may need periodic maintenance; in particular the on-line isotopic separation unit in the mercury loop.
EURISOL-DS Multi-Megawatt Target: Remote Handling Equipment
Cyril Kharoua, Olivier Choisnet, Yacine Kadi, Karel Samec (CERN)
The design proposed within Task #2 of the EURISOL Design Study for the remote handling of the mercury converter target and its associated loop is presented with particular emphasis on achieving rapid turn-around during routine maintenance.
The converter target needs to be completely exchanged every four months due to the high irradiation damage sustained. Other components are less susceptible to damage but may need periodic maintenance; in particular the on-line isotopic separation unit in the mercury loop.
EURISOL-DS Multi-MW Target: Cost Analysis for a Proposed Development Phase
Karel Samec, Mats Lindroos, Yacine Kadi, Etam Noah, Jacques Lettry (CERN)
Werner Wagner, Knud Thoms...
The EURISOL Design Study has reached final completion and the three institutes, CERN, IPUL and PSI, participating in the development of the Multi-Megawatt target station have met the objective of a reliable, affordable and credible design. The costs involved in the full development of such a target are forecast to reach 200 million €, approximately 15% of the total costs of the EURISOL facility.
A breakdown of the costs is presented as well as an outline of future possible R&D efforts aimed at improving reliability and safety of the facility. Another important goal of the proposed R&D is to minimise development risk by focusing resources, early on in the project, on areas identified as presenting a particular risk. An example clearly identified in the study would be the conditioning of the contaminated Mercury, both during the lifetime of the facility and after decommissioning.
Deliverable D4: Off line thermal and fluid dynamics test
K. Samec et al.
Early on in the EURISOL-DS study the converter target was identified as a major component on the critical path to demonstrating the overall concept of such a facility; without the target the entire project would not be feasible. The very harsh environment under which a target is to operate under irradiation is best summed by its governing parameters listed in Table 1.
Obtaining experimental proof of two independent target designs; one featuring a beam window, the other without, was therefore instrumental to proving a viable concept for the overall EURISOL facility. Considerable effort was expended on ensuring adequate testing of the designs for which all participants, in particular IPUL, devoted much time and effort.
Deliverable D1: Engineering study of the Hg converter
K. Samec et al.
The development of high-power converter targets otherwise known as neutron sources is today the focus of much attention, driven by the need for ever greater densities of neutron fluxes which are required in the fundamental sciences such as neutron imagery, isotope production and also for the more long-term goal of realising a hybrid sub-critical nuclear reactor. The neutrons in a converter target are produced by a process known in physics as spallation whereby a heavy Z atom releases neutrons below 20 [MeV] when hit by an incoming proton.
The Eurisol initiative seeks to develop such an isotope production facility to provide the scientific community with the means to achieving high yields of isotopes and extending the variety of isotopes thus produced towards more exotic types rarely seen in existing facilities.
The proposed ISOL facility would use both (a) several 100 kW proton beams on a thick solid target to produce RIBs directly, and (b) a liquid metal 1–5 MW ‘converter’ target to release high fluxes of spallation neutrons which would then produce RIBs by fission in a secondary uranium carbide (UCx) target. An alternative windowless liquid mercury-jet ‘converter’ target to generate the neutrons has also been proposed for this Multi-MW target station.
The Multi-MW converter target at the heart of the projected facility is designed to create isotopes by fissioning uranium carbide (UC) target arranged coaxially around a 4 MW converter target. It is therefore essential that the target be as compact as possible to avoid losing neutrons to capture whilst maximising the neutron flux to enhance the number of fissions per second in the UC targets.
EURISOL-DS Multi-MW Target: A safe way to run the CGS converter
Cyril Kharoua, Yacine Kadi, Karel Samec (CERN)
This technical note summarizes the design calculations performed within Task#2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) on the safety hull of the CGS design of the mercury converter. A study was carried out in order to propose a configuration for the safety hull and the connection between the target and the accelerator. The results of these calculations show a layout and a design proposal for the safety barrier of the EURISOL DS target design.
EURISOL-DS Multi-MW Target: Cavitations detection by the a Laser Doppler Vibrometer
Cyril Kharoua, Yacine Kadi, Jacques Lettry, Laure Blumenfeld, Karel Samec (CERN)
Knud Thomsen, Serg...
This technical note summarises the innovative measurement devices used within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) to detect the occurrence of cavitation in liquid metal flowing inside the CGS target mock-up.
During the METEX hydraulic experiment carried out at IPUL (Institute of Physics of the University of Latvia), a Laser Doppler Vibrometer was used to characterize the wall vibrations of the beam window at different flow regimes. A series of tests proved the high sensitivity of the LDV to detect the occurrence of cavitation in the liquid metal flowing inside the target. In this context, a dedicated test procedure was developed to establish the validity of using LDV for detecting the onset of cavitation.
EURISOL-DS Multi-MW Target: Study of the WTF Liquid Metal Proton-to-Neutron Converter
Cyril Kharoua, Yacine Kadi (CERN)
Erik Platacis, Kalvis Kravalis (IPUL)
This technical note summarises the design calculations and experiments performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) for the WTF (Windowless Transverse Film) mercury converter.
A preliminary study was carried out in order to determine the heat deposition within the mercury and estimate the flow velocity needed in the film. The geometry used is based on previous analysis simulated using the Monte Carlo code FLUKA.
Many experiments have been performed at IPUL to optimise an inlet nozzle capable to create a stable film. The experimental program followed to design the film former will be detailed in this report.
The results of these calculations are addressing the baseline parameters. Particularly, a 1 GeV proton beam with a sigma ~2 mm Gaussian distribution impacting on a 4x30x40cm long target. The very high power density requires about 5m/s velocity in the region where the heat deposition is maximum.
CFD post analysis of METEX-tests
Laure Blumenfeld, Cyril Kharoua, Yacine Kadi, Karel Samec, Mats Lindroos (CERN)
This technical note summarises the additional CFD performed after the completion of the hydraulic METEX 1 and METEX 2 data tests to validate CFD turbulent simulation of liquid metal with the LES, RANS and SST model.
EURISOL-DS Multi-MW Target: Risk Register
C. Kharoua and Y. Kadi (CERN)
The purpose of the risk register is to identify and rank the risk inherent to the installation, operation, maintenance, dismantling and disposal of each item of the facility and to propose ways of mitigating such risks.
It is an important input for the safety report which will be mandatory for the study towards the construction of the EURISOL Facility.
EURISOL-DS Multi-MW Target: Design of the EURISOL Liquid metal loop
K. Samec (PSI)
A Mercury loop capable of evacuating 2.7 MW of the 4 MW deposited in the Eurisol liquid metal neutron spallation target is described in the present design study.
The study takes into account the effects on the loop of temperature, pressure, irradiation, liquid metal corrosion, including both steady state operations and normal transients.
Accidental conditions are only briefly alluded to in the form of a description of the protection barriers and envisaged mitigation strategies.
Innovative Waste Management in the Mercury Loop of the EURISOL Multi-MW Converter Target
PSI: Jörg Neuhausen, Dorothea Schumann, Rugard Dressler, Susanne Horn, Sabrina Lüthi, Stephan ...
The choice of mercury as target material imposes various questions concerning the safe operation of such a system that are related to the physical and chemical properties of the target material itself and the nuclear reaction products produced within the target during its life time of several decades. Therefore, a subtask was created within the EURISOL-DS project that is concerned with studying an innovative waste management for the generated radioactivity by chemical means. Such a study strongly depends on the radioactive inventory and its distribution throughout the target and loop system. Radioactive inventory calculations were performed within task 5 [6]. The distribution of nuclear reaction products and their chemical state that can be expected within the target and loop system is one of the topics covered in this report. Based on the results obtained by theoretical studies as well as laboratory scale experiments, the feasibility of waste reduction using chemical methods, both conventional (e.g. leaching, distillation) and innovative (e.g. surface adsorption) are studied experimentally. The results and their implications on separation procedures that can be favourably applied to a spallation target system are discussed with respect to both handling of the radioactive waste and extraction of valuable nuclides for medical, scientific and industrial applications.
EURISOL-DS Multi-MW Target: Thermal Behaviour of the fission target disk arrangement inspired by the MAFF project
Cyril Kharoua, Yacine Kadi and the EURISOL-DS Task#2 collaboration
This technical note summarises the design calculations performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) [1] for the thermal behaviour of the fission target.
A preliminary study was carried out in order to determine the heat deposition within the fissile material and estimate the temperature rise. This new solution takes into account the problems related to effusion/diffusion of radioactive isotopes inside a thick target. To enhance the extraction rates and the thermal behaviour it is proposed to study a solution where the fissile material is split into an arrangement of disks.
Multi MW target station: Engineering design construction of functional Hg Loop
I. Bucenieks, N. Jēkabsons, P. Lūķis, K. Kravalis, A. Romančuks, J. Šeimanis and...
Task#2 Deliverable D3
EURISOL-DS Multi-MW Target: Experimental program associated to validation of CFD simulations of the mercury loop
Laure Blumenfeld, Cyril Kharoua, Yacine Kadi, Karel Samec, Mats Lindroos and the EURISOL-DS Task#2 c...
At the core of the Eurisol project facility, the neutron source produces spallation neutrons from a proton beam impacting dense liquid. The liquid circulates at high speed inside the source, a closed vessel with beam windows.
This technical note summarises the needed of the hydraulic METEX 1 and METEX 2 data tests to contribute to validate CFD turbulent simulation of liquid metal with the LES model and FEM structural model as well as a-dimensional analysis of Laser Dopplet Velocimetry for cavitation measurements.
EURISOL-DS Multi-MW Target. Test predictions for the converter target
Karel Samec, Mats Lindroos, Yacine Kadi,
Roberto Rocca, Cyril Kharoua
AB Dept. ATB
The Eurisol project has been initiated by the European Commission to demonstrate the
feasibility of a facility for producing large yields of exotic isotopes.
At the core of the projected facility, the neutron source produces spallation neutrons from a
proton beam impacting dense liquid metal. The liquid metal circulates at high speed inside
the source, a closed vessel with a beam window. The type of the design is diversely
described as coaxially guided stream or CGS; an outer annulus converges towards a
concave conical shell from which the liquid metal reverses back in the opposite direction.
The current CGS design of the source has been built and is to be tested. This technical
report summarises preparations for the test and predictions.
EURISOL-DS Multi-MW Target Preliminary Study of the Thermal Behaviour of the fission target inspired by the MAFF project
Cyril Kharoua, Yacine Kadi
This technical note summarises the design calculations performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) [1] for the thermal behaviour of the fission target. A preliminary study was carried out in order to determine the heat deposition within the fissile material and estimate the temperature raise.
EURISOL-DS Multi-MW Target Preliminary Study of the WTF(Windowless Transverse Film) Liquid Metal Proton-to-Neutron Converter
Cyril Kharoua, Yacine Kadi, Karel Samec, Roberto Rocca
This technical note summarises the design calculations performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL-DS) [1] for the WTF (Windowless Transverse Film) mercury converter. A preliminary study was carried out in order to determine the heat deposition within the mercury and estimate the mercury velocity needed in the film. The geometry used is based on previous analysis simulated using the Monte Carlo code FLUKA [2]. The results of these calculations show the baseline parameters, which will be used for the detailed design. Particularly, with a 1 GeV proton beam with a ~2 mm Gaussian distribution on a 4x30x40cm long target and with a 5m/s velocity at the peak power density region seems a suitable solution.
Design of a liquid metal target loop for a high power spallation
Andreas Vetter (PSI)
Diplomarbeit zur Erlangung des Grades Diplom-Ingenieur
Technische Universität Berlin
This thesis shows the lay-out of the liquid metal loop, which is designed to evacuate 3.0 MW of thermal power. It describes the function and sizing of the piping and components. The thesis deals with the choice of the pump, the expansion tank/gas separator and the heat exchanger using water as cooling fluid as well as instrumentation.
EURISOL-DS METEX1: LDV measurement to detect Cavitations
Jacques Lettry, Yacine Kadi, Cyril Kharoua, Karel Samec
Laser Doppler Vibrometers (LDV) are optical instruments for accurately measuring velocity and displacement of vibrating structures completely without contact.
A rugged optic head (roughly the same size as a video camera) mounts to a tripod and can be easily pointed at a vibrating object.
EURISOL-DS METEX: CERN SAFETY COMMISSION RECOMMENDATIONS
J.Gulley (CERN: SC/GS)
Following a request from M. Lindroos (CERN, AB Department) a visit to the EURISOL mercury target experiment at
IPUL (Institute of Physics of University of Latvia) outside Riga in Latvia was organized for 17th September 2008 with J.
Gulley (CERN Safety Commission, chemical safety expert) accompanied by K. Samec (CERN, AB Department) and K.
Thomsen (Paul Scherrer Institute, PSI). The aim of the visit was to provide general recommendations to IPUL on health
and safety issues related to the use of mercury, with the objective being to reduce exposure to acceptable levels, so
far as is reasonably practicable. An in‐depth process safety study using a systematic risk assessment/hazard
identification technique was outside the scope of the study.
EURISOL-DS METEX: Operation Manual for the METEX1-Exeriment in IPUL
E. Platacis, A. Zik (IPUL),
F.Groeschel, S. Dementjev (PSI)
Within the EURISOL DS project of the 6th Framework Program the METEX1 experiment will be carried out in the Hg-loop at IPUL to test the target mockup developed and built by PSI. The tests should demonstrate the feasibility of such a target to cope with the hydraulic conditions required to manage a 4 MW proton beam. The flow conditions have been extensively modeled by CFD calculations and the experiment serves to validate such calculations. The mockup has been built at PSI applying strict quality rules with respect to conformance of design, inspection of welds. The mockup has been pressure tested at 12.5 bar prior to shipment.
The Hg loop has been modified by IPUL to comply with the test requirements (see [1]). The necessary quality checks have been carried out in the February of 2008 at a pressure of 7 bar.
The endeavor is a joint undertaking of the Task 2 partners CERN, IPUL and PSI.
EURISOL-DS METEX1: Hydraulic mercury test of the target mock-up. Technical requirements on mercury loop
S.Dementjev, R.Milenkovic, and F.Groeschel
The target hydraulic test will be carried out on IPUL (Latvia) mercury loop DN100. The loop will be adapted for the experiment on the basis of these technical requirements.
EURISOL-DS METEX: Post-processing of the experimental data: Test matrix, Pre-calculations, Data Recording and Mining, Statistical and Advance Data Analysis
R. Milenkovic and S. Demetjevs
E. Manfrin, F. Barbagallo, S. Joray, J. Patorski, F. Groeschel
At its first stage, the hydraulic and structural test of the EURISOL target mock-up, named METEX1 (MErcury Target EXperiment 1), accompanied by extended thermal-hydraulic and structural computational studies, have been carefully planned and prepared at PSI (PaulScherrer Institut). The experiment will be performed by PSI on the adopted IPUL-loop in June, 2008 at IPUL, Riga, Latvia.
The main objective of this document is to give a brief overview of the following: the test matrixaccompanied by computational results, the procedures and methods, which are to be used fordata acquisition, signal post-processing and validation of the computational methods.
Hydraulic simulation of the flow condition at the inlet of the beam entrance window of the EURISOL converter target
V. Geza and R. Milenkovic
The main objective of the computational study presented here, is to calculate the velocity distribution at the inlet of the beam entrace window and to provide computational data, which are to be compared with the experimental data. The experimental data are to be acquired during forthcoming hydraulic test of the Eurisol target mock-up.
EURISOL-DS METEX: Cooling and Temperature Control of the Mercury Loop
Stefan Joray
The cooling of the mercury loop is described on pages two, three and four. The gaps in the water jackets of the heat exchangers are too large and the cooling water capacity is too low. Convection from the wall into water is bad. The mercury temperature is too high. On page five is a proposal how the mercury temperature can be kept low and constant.
EURISOL-DS Multi-MWatt Hg Target: Parameters List
Y. Kadi, C. Kharoua and Y. Romanets
The following table describes the main parameters affecting the design of the multi-MW Hg target station
Engineering design and construction of a function Hg – loop & Contribution of IPUL in windowless Hg-target feasibility studies
J. Freibergs, E. Platacis, K. Kravalis, A. Ziks
&
I.Platnieks
Within EURISOL – DS, a liquid metal /LM/ spallation target with a power of several Megawatt is designed to provide neutrons to a fission target. The target station that allows the full intensity of a 4 MW proton beam to be used for RIB production will require new advanced technology. It is a critical component of EURISOL.
For a power density above 103 MW/m3 the windowless, free-surface, molten LM-jet is proposed as a target since it avoids the very serious lifetime – shortening damage caused by the power proton beam in any system
Thermo-Hydraulic Optimisation of the EURISOL-DS MMW Hg target
M. Ashrafi-Nik
The present document describes the thermal and the stress analysis of the final design of the EURISOL DS target. The preliminary design by Q. Prétet, R. Milenkovic and B. Smith was used as a starting point for further improvements to reduce stresses in the hull; the results of these computations are summarised in this document.
All variants studied to attain the objective are documented using CFD to assess the effects of different flow configurations on the temperature distribution in the target liquid metal and structural analysis for determining the stresses and temperatures in the target structure.
Multi-MW target station: Beam Window Issues and Transverse Film Target
A.Herrera-Martinez and Y.Kadi
The analysis of the EURISOL-DS Multi_MW target precise geometry has proved that large fission yields can be achieved with a 4 MW, providing a technically feasible design to evacuate the power deposited in the liquid mercury. Different designs for the mercury flow have been proposed, which maintain its temperature below the boiling point with moderate flow speeds (maximum 4 m/s).
Analysis of the target window
Quentin Prétet
Rade Milenkovic
Brian Smith
Preliminary CFD and structural analysis of the liquid metal target window. A first atatempt at optimising the structure from the point of view of reducing stresses has achieved in a small reduction. Further efforts are needeed and on-going
Multi-MW target station: Baseline Parameters
Y.Kadi
Baseline parameters of the Multi-MW liquid Hg neutron converter
HIE-ISOLDE: Baseline Design of a Solid Neutron Converter Driven by 160 MeV Protons
Y.Kadi and A.Herrera-Martinez
The European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS) aims at the design of several spallation and fission targets for the production of radioactive isotopes. Namely, direct targets, where high-energy protons interact directly with the fission targets, as well as the design of a Multi-MW proton-to-neutron converter coupled with a fission target. For the later, several options have been proposed, including the use of a relatively low energy (in the hundreds of MeV) high intensity proton beam. In this scope, the neutronic characteristics of a tantalum n-converter/fission-target system have been established (although not yet optimised) for a reference proton energy of 160 MeV. A set of simulations has been carried out for different design requirements and different characteristics of the proton beam. An extensive comparison of the main physical parameters has also been carried out, in order to allow the optimal engineering design of the whole target station.
Multi-MW target station: Comparative Neutronic Performance of the Baseline Configuration vs. the Hg-Jet Option
A.Herrera-Martinez and Y.Kadi
This technical report summarises the comparative study between several design options for the Multi-MW target station performed within Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS) [1].
Previous analyses were carried out, using the Monte Carlo code FLUKA [2], to determine optimal values for relevant parameters in the target design [3] and to analyse a preliminary Multi-MW target assembly configuration [4]. The second report showed that the aimed fission rates, i.e. ~1015 fissions/s, could be achieved with such a configuration. Nevertheless, a preliminary study of the target assembly integration [5] suggested reducing some of the dimensions. Moreover, the yields of specific isotopes have yet to be assessed and compared to other target configurations.
This note presents a detailed comparison of the baseline configuration and the Hg-jet option, in terms of primary and neutron distribution, power densities and fission product yields. A scaled-down version of the baseline configuration (i.e. reduced radius and length), is proposed and compared with the other designs.
The results confirm the feasibility of the reduced target configuration, while obtaining fission product yields comparable to those of the Hg-jet layout, without the technical problems of the latter. Significant fission rates may be obtained with 4 MW of beam power and few one-litre UnatC3 targets. Moreover, the energy deposited in the liquid metal may be evacuated with reasonable flow rates.
Multi-MW target station: Neutronic Calculations of the Baseline Design
A.Herrera-Martinez and Y.Kadi
This document summarises the study performed within the Task #2 of the European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS) [1] to design the Multi-MW proton-to-neutron converter.
A preliminary study [2] was carried out in order to understand the nature of the interactions taking place in the proton-to-neutron converter and their impact on the design of the facility. Namely, the target dimensions and material composition, type of incident particle, its energy and the beam profile were analysed in the aforementioned technical note, and their optimum values were suggested in the conclusions.
The present work is based on the results of the previous study and uses the same methodology, namely Monte Carlo simulations with FLUKA [3]. This note describes the performance of a Hg target design and addresses more detailed issues, such as the composition of the fission target and use of a neutron reflector. It also attempts to integrate those components together and estimate the whole performance in terms of number of fissions, isotopic yields and power densities.
The results of these calculations show the feasibility of this Multi-MW target design and the possibility of achieving the aimed fission rates with a reduced fission target. The assembly has been characterised in terms of neutronics and power densities, both key factors in the technical design, due to the high isotopic yields aimed and the large power densities foreseen.
EURISOL Multi-MW Target: First thermal-hydraulic studies for the EURISOL high-power liquid-metal target using Computational Fluid Dynamics
Trevor V. Dury
A scoping study of a mercury target for the Multi-Megawatt Proton-to-Neutron Converter of the
EURISOL Project has been made at PSI using the Computational Fluid Dynamics (CFD) code
CFX-4. A mesh model of a horizontal target with forced circulation was used which had been
originally proposed for the European Spallation Source (ESS). The heat deposition profile
which was applied produced a total of 4 MW of heat in the fluid and 13.4 kW in the window,
EURISOL Multi-MW Target: Investigation of the hydrodynamics of liquid metal (Hg) jet
J. Freibergs et al.
In order to develop a windowless target it is necessary to investigate the hydrodynamics of liquid metal (Hg) jet. On the basis of the schematic layout of a high-power target module presented in Ref. [2], and the parameters of the windowless target (speed of the mercury jet up to 30 m/s, diameter of jet 10-20 mm and length of jet about 1 m), a first estimation of the parameters of the main components of a Hg-loop has been obtained by the Institute of Physics, University of Latvia. A preliminary engineering design of a functional Hg-loop to be constructed soon is also proposed. A simplified water stand has been developed with the ability of testing different Hg-nozzle configurations. The tests carried out showed that the kinetic energy of the jet is so high that the coaxial water flow at contact point is transformed into small bubbles (spray). The characteristics of the jet were shown to depend on the pressure of the stand.
EURISOL Multi-MW Target: Preliminary Study
A.Herrera-Martínez and Y.Kadi
This technical note summarises the design calculations performed within Task #2 of the EURopean Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS).
A preliminary study was carried out in order to determine the optimum value of relevant parameters in the target design. Different scenarios were simulated using the Monte Carlo code FLUKA. Namely, sensitivity studies were performed to assess the impact of the projectile particle energy on the neutronics and energy deposition in the spallation target. The optimum target dimension was also studied for every case as well as the proper target material for the liquid metal proton-to-neutron converter, since mercury and lead-bismuth eutectic are reasonable options. The effect of the beam width on the power densities was also evaluated, taking into account the geometrical limitations of the facility. Finally, a comparison between protons and deuterons as primary particles was performed, acknowledging the limitations of using FLUKA for these simulations.
The results of these calculations show the benefit of using protons as primary particles and increasing their energy, in order to reduce the high power densities occurring in the first few centimetres downstream from the interaction point. Particularly, a 2 GeV proton beam with a ? ~15 mm Gaussian distribution on a 15 cm radius 50 cm long target seems a suitable trade between increasing the neutron and fission yields and reducing the power densities in both, the liquid metal and fission targets.
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