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General Allgemeines ual Design Report ual Design Report Concept Jülich High Brilliance Neutron Source Source Jülich High Brilliance Neutron 8 Conceptual Design Report Jülich High Brilliance Neutron Source (HBS) T. Brückel, T. Gutberlet (Eds.) J. Baggemann, S. Böhm, P. Doege, J. Fenske, M. Feygenson, A. Glavic, O. Holderer, S. Jaksch, M. Jentschel, S. Kleefisch, H. Kleines, J. Li, K. Lieutenant,P . Mastinu, E. Mauerhofer, O. Meusel, S. Pasini, H. Podlech, M. Rimmler, U. Rücker, T. Schrader, W. Schweika, M. Strobl, E. Vezhlev, J. Voigt, P. Zakalek, O. Zimmer Allgemeines / General Allgemeines / General Band / Volume 8 Band / Volume 8 ISBN 978-3-95806-501-7 ISBN 978-3-95806-501-7 T. Brückel, T. Gutberlet (Eds.) Gutberlet T. Brückel, T. Jülich High Brilliance Neutron Source (HBS) 1 100 mA proton ion source 2 70 MeV linear accelerator 5 3 Proton beam multiplexer system 5 4 Individual neutron target stations 4 5 Various instruments in the experimental halls 3 5 4 2 1 5 5 5 5 4 3 5 4 5 5 Schriften des Forschungszentrums Jülich Reihe Allgemeines / General Band / Volume 8 CONTENT I. Executive summary 7 II. Foreword 11 III. Rationale 13 1. Neutron provision 13 1.1 Reactor based fission neutron sources 14 1.2 Spallation neutron sources 15 1.3 Accelerator driven neutron sources 15 2. Neutron landscape 16 3. Baseline design 18 3.1 Comparison to existing sources 19 IV. Science case 21 1. Chemistry 24 2. Geoscience 25 3. Environment 26 4. Engineering 27 5. Information and quantum technologies 28 6. Nanotechnology 29 7. Energy technology 30 8. Cultural heritage 31 9. Soft matter, biomaterials and health 31 10. Radiation safety 32 11. Neutron methods 35 11.1 Elastic scattering 35 11.2 Inelastic scattering 36 11.3 Analytics 38 11.4 Imaging 40 12.5 Irradiation 41 11.6 Isotope production 42 11.7 Particle physics 43 11.8 Nuclear spectroscopy 44 11.9 Neutron interferometry 45 CDR | HBS 3 V. Conceptual design 47 1. Neutron production 48 2. Accelerator 49 2.1 Top level requirements 49 2.2 Choice of technology 51 2.3 Design philosophy 54 2.4 Proton source 56 2.5 Low energy beam transport and chopper 57 2.6 Radio frequency quadrupoles 59 2.7 Medium energy beam transport 62 2.8 Drift tube linac 62 2.9 RF system 64 3. Multiplexer 66 3.1 Requirements 67 3.2 Layout 68 3.3 Beam dynamics 70 3.4 Magnet design 72 4. Proton beam transport 74 4.1 Proton beam dump 77 5. Target 78 5.1 Material selection 79 5.2 Neutron spectrum 80 5.3 Basic target design 80 6. Moderator-reflector assembly 87 6.1 Thermal moderator 88 6.2 Cold moderators 92 7. Reflector 96 8. Shielding 97 9. Target station design 101 9.1 Cooling 102 9.2 Neutron beam extraction 104 9.3 Target handling 105 VI. Instrumentation 107 1. Imaging 109 1.1 Cold neutron imaging 109 1.2 Thermal neutron imaging beamline 110 1.3 Diffractive neutron imaging beamline 112 1.4 Epithermal and high energy neutron imaging beamline 113 4 CDR | HBS 2. Diffraction 113 2.1 Thermal powder diffractometer with flexible and high resolution 114 2.2 Diffractometer for nanoscaled and disordered materials 115 2.3 Single crystal and powder magnetism diffractometer 117 2.4 Macromolecular diffractometer 118 2.5 Engineering diffractometer 120 3. SANS 121 3.1 High resolution SANS 121 3.2 GISANS 123 4. Reflectometry 124 4.1 Specular reflectometer with SELENE optics 124 4.2 Reflectometer with off-specular scattering 126 5. Spectroscopy 127 5.1 Cold chopper spectrometer 127 5.2 High energy chopper spectrometer 128 5.3 XTOF spectrometer with high Q -resolution 129 5.4 Vibrational spectrometer 131 ⃗ 5.5 Backscattering spectrometer 131 5.6 Neutron spin echo 132 6. Analytics 134 6.1 Prompt gamma neutron activation analysis 134 6.2 Neutron depth profiling 136 VII. Operation 139 1. Regular operation 139 2. Control systems 139 2.1 HBS machine control system 140 3. Instrument control system 142 3.1 Requirements and functionality 142 3.2 Architecture and implementation 143 4. Risk management and improvement 145 VIII. Safety 147 1. Non-radiological safety 147 2. Radiological safety 147 3. Handling of activated material 149 CDR | HBS 5 IX. Infrastructure 155 1. Building requirements 156 2. Energy supply and cooling 156 X. Commissioning, decommissioning 159 1. Commissioning 159 2. Decommissioning 159 3. Waste management 160 XI. Investments, costing & timeline 161 XII. Cooperation and delineation 165 Acknowledgement 167 A. Appendices 169 1. Production of secondary products 169 2. Beam brilliance at HBS 172 3. Brilliance calculation 173 6 CDR | HBS . I I. EXECUTIVE SUMMARY • The solution of major grand challenges of humankind is largely based on progress in mate- rials research of natural and articial matter. Success depends critically on the availability of powerful methods being able to unravel structure and function of matter at dierent length and time scales. • In this context, neutrons are indispensable microscopic probes. They are used to unravel the structure and dynamics of matter from the mesoscale to the picoscale and from seconds to femtoseconds in an ever-increasing number of disciplines and thus make essential contribu- tions to solutions of the grand scientic and technological challenges of the future. • Europe has the world leading neutron user community. More than 8000 users utilize the available neutron sources in Europe, requesting twice the available capacity oered per year. Within Europe, Germany has the most productive community in terms of scientic output. • The European success of research with Neutrons is based on a hierarchical network of neutron facilities: from low ux sources, which provide the foundation by educating the next generation of neutron users and oering a platform for method development, via medium ux sources having a broader instrumentation, which provide in addition capacity and capability, to ag ship facilities (ILL and in future ESS) which are essential for the most demanding ux-hungry experiments. • As has been pointed out by an ESFRI working group, this leading position is currently challenged by the slow dying o of older research reactors which became critical in the middle of last century. This problem has been addressed in the national strategy papers of several European neutron communities and is being tackled at present within the League of advanced European Neutron Sources (LENS). • With the goal to reestablish a healthy ecosystem of neutron facilities within Europe and to further develop the neutron landscape for science and industry in Germany and Europe, the Julich¨ Centre for Neutron Science (JCNS) of Forschungszentrum Julich¨ GmbH has worked on a novel approach to neutron research facilities: the HBS project for a High Brilliance neutron Source. The present document summarizes the concept of such a facility in a Conceptional Design Report (CDR). • The fresh approach of the HBS project is due to several paradigm changes: – the basic process for neutron release from atomic nuclei of the HBS is neither ssion, nor spallation, but nuclear reactions based on the impact of low energy protons on a metal target. While this concept has already been realized in small Compact Accelerator CDR | HBS 7 . I driven Neutron Sources (CANS), it only now becomes viable for a high-end facility by employing the latest scientic and technological advances. Such a facility avoids the need for nuclear licensing and signicantly reduces the shielding requirements. – instead of aiming at the highest source strength, HBS maximizes brilliance, the relevant physical parameter for most neutron beam instruments; ”HBS produces less neutrons, but uses them more eciently”. This approach immediately translates in decreased costs for installation and operation. – instead of providing one neutron source / moderator for all instruments, which necessarily requires compromises, HBS considers the source as an integral part of the instrument and delivers optimal pulse structure and neutron spectrum to every single instrument; ”HBS delivers individually tailored beam characteristics for each instrument, instead of one ts all”. This approach increases the performance of the instruments. – instead of aiming at a certain size for a facility, the HBS concept is highly exible and scalable from large laboratory size for local use at universities and industrial companies to full-edged and highly competitive user facility. The conceptual design for the large laboratory facility has already been published under the name NOVA ERA. Such a neutron source has the potential to ”bring neutrons to the users instead of users to neutrons”. • HBS type of sources will provide new capacity and additional capability to research with neu- trons. Optimizing for brilliance makes the HBS type of sources well suited for research on small sample volumes, important e.g. in the elds of life science, nanotechnology or engineering. Figure I.1: General layout of the accelerator-based high brilliance neutron source facility • The reference design of HBS comprises the following main components (see gure): – a high power linear proton accelerator with an end energy of 70 MeV, a proton beam current of 100 mA and a duty cycle of 4.3% – a multiplexer which distributes the proton pulses to three target stations which operate at dierent frequencies of 24, 96 and 384 Hz, each one optimized for a certain group of neutron beam instruments 2 8 CDR | HBS . – target-moderator-reector assemblies that oer pulsed neutron beams at optimal fre- I quency, pulse duration and neutron energy spectrum to full the needs of each individual instrument. – a number of instruments grouped around each target station so that they receive the optimal pulse structure while individual one dimensional ”nger” moderators provide the adapted phase space volume to each individual instrument • With this reference design, neutron beam instruments at the HBS will be highly competitive to instruments at existing medium-to high ux neutron sources thus underpinning the future agship facility ESS.
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