IFMIF-DONES is a facility under construction in Granada, whose main goal is the validation and characterization of materials under a fusion prototypic irradiation field. This field is created by the ...interaction of a high energy intense continuous deuteron beam and a flowing liquid lithium target. The requirements imposed on the beam at the interaction point are a complex trade-off among the scientific experimental needs for the materials irradiation defined at the top-level requirements (20 dpa in a volume of 0.3 dm3 and 50 dpa in 0.1 dm3), and the technical constraints of several systems such as the Accelerator Systems, the Lithium Systems, and the Test Systems. Recent simulations with the initial definition of beam-on-target requirements showed the necessity of redefining them in order to fulfill the irradiation needs. This contribution will address the main challenges to gather the inputs for the definition and reassessment of the beam-on-target requirements. A comparison detailing the main changes compared to the previous ones will be given, together with a short overview of the studies ongoing by different systems to analyze the impact of each beam-on-target requirements on the performance of the whole facility.
•Fusion materials irradiation.•Deuteron accelerator.•High current accelerator.•Beam delivery system.•Beam on-target.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
For the Isotope Decay At Rest (IsoDAR) experiment in neutrino physics (searching for sterile neutrinos), we have developed a novel compact isochronous cyclotron with direct injection through ...an axially embedded RFQ. For IsoDAR to be decisive within five years of running, 10 mA of protons, cw at 80% duty factor are needed on a neutrino production target. To alleviate space charge in the cyclotron driver, we accelerate 5 mA of
H
2
+
, to be broken up into 10 mA of protons after extraction from the cyclotron. An open question that we are answering with this paper is whether the beam losses from gas-stripping (the removal of electrons from
H
2
+
through the interaction of the beam ions with the residual gas in the accelerator) are going to be a significant challenge. Using a newly added feature to the well-established Object-Oriented Parallel Accelerator Library code, we calculate gas-stripping losses in the IsoDAR cyclotron using realistic beam distributions, magnetic fields, gas composition, and pressure. We show that to maintain losses due to dissociation below 1% over the entire acceleration region, a vacuum of at least 6 × 10
−7
mbar is required.
The ion source is one of the most relevant elements in a cyclotron, since it determines the injection into the accelerator. An internal cold-cathode Penning ion source has been chosen for the AMIT ...compact cyclotron. This kind of source is extensively used in cyclotrons to produce negative hydrogen ions. The compactness of the accelerator constrain the beam diagnostic in the cyclotron, motivating the development of an external experimental facility for the commissioning of the ion source. In this paper, the validation of the ion source design and the characterization of the H− beam production are presented. Different chimney geometries modifying the distance between the plasma column and the extraction wall have been tested to obtain the best relation between ion production and plasma conditions. In addition, experimental measurements of the beam profile have been carried out. Current experimental results provide relevant information for the operation in the final cyclotron assembly and the final beam current optimization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
IFMIF-DONES (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is a fusion materials testing facility that is currently being designed under the framework of a work ...package of the EUROfusion Consortium. It will use a 125mA at 40MeV deuteron beam to generate a high neutron flux through Li(d,xn) stripping nuclear reactions in a liquid lithium target. The High Energy Beam Transport line (HEBT), the most upstream system of the IFMIF-DONES accelerator, is responsible for the guidance and shaping of the beam towards the target. Additionally, during commissioning periods, the HEBT is also responsible for diverting the beam, through the Beam Dump Transport Line, to the Beam Dump for testing purposes. The HEBT is spread along different rooms and zones: the Accelerator Vault, the Radiation Interface Zone (RIZ), and Target Interface Room (TIR). The engineering design of the HEBT components situated within the TIR and RIZ has been updated to satisfy new requirements, with a focus on ensuring the protecting of the Fast Isolation Valve (FIV) from the backscattered radiation from the target. These modifications include relocating the FIV from the TIR to the RIZ, adjusting the building layout to accommodate the new FIV module, configuring an enclosure cabinet for the RIZ, and adding local shielding to extend the lifetime of the FIV seal actuators. This work describes the current status of these TIR and RIZ engineering design, including radioprotection, commissioning and maintenance plan, beam diagnostics devices, beam dynamics and new remote handling approaches, as well as the layout and integration of the required components along the beamline. The TIR and RIZ are critical areas for IFMIF-DONES, and their design and operation must be compliant with functional, reliability and safety requirements. The updated design addresses potential issues and enhances the facility’s overall functionality.
•Collimator redesigned with new coolant fluid for the near TS safety measures.•TIR layout shift to two LRU frees space for new elements.•TIR-RIZ wall thickness reduced by one meter for space.•Enclosure cabinet in RIZ stores argon atmosphere for the FIV.•FIV lifespan doubled by implementing local shielding strategies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
5.
Preliminary design of the HEBT of IFMIF DONES Nomen, Oriol; Sanchez-Herranz, Daniel; Oliver, Concepción ...
Fusion engineering and design,
April 2020, 2020-04-00, 20200401, Volume:
153
Journal Article
Peer reviewed
Open access
•Preliminary design of the HEBT of the DONES accelerator is described.•Requirements considered for the design has been included.•Beam dynamics, diagnostics and vacuum studies are explained.•Remote ...handling and radioprotection studies are described.•The feasibility of a HEBT design fulfilling all the requirements is demonstrated.
IFMIF-DONES (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is currently being developed in the frame of the EUROfusion Early Neutron Source work package (WPENS) and will be an installation for fusion material testing, that will generate a flux of neutrons of 1018 m−2s−1 with a broad peak at 14 MeV by Li(d,xn) nuclear reactions thanks to a 40 MeV deuteron beam colliding on a liquid Li flow.
The accelerator system is in charge of providing such high energy deuterons in order to produce the expected neutron flux. The High Energy Beam Transport line (HEBT) is the last subsystem of the accelerator and its main functions are to guide the deuteron beam towards the Lithium target and to shape it by the use of magnetic elements to the reference beam footprint at the Lithium Target.
The present work summarizes the current status of the HEBT design, including beam dynamics, vacuum, radioprotection, diagnostics and remote handling studies performed, along with the layout and integration of the line.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
6.
The LIPAc beam dump Brañas, Beatriz; Arranz, Fernando; Nomen, Oriol ...
Fusion engineering and design,
02/2018, Volume:
127
Journal Article
Peer reviewed
•The complete design of the Beam dump for the LIPAc (1 MW 9 MeV continuous deuteron accelerator) is presented.•The beam stopping piece is a water cooled copper cone with a 6.8° angle and 2.5 ...length.•The neutron production and activation caused by the beam-copper interaction determines many of the design features.
The International Fusion Materials Irradiation Facility (IFMIF) aims to provide an accelerator-based, D-Li neutron source to produce high energy neutrons at sufficient intensity and irradiation volume for fusion materials qualification. The LIPAc is a 125 mA 9 MeV continuous wave deuteron accelerator whose components are under construction mainly in Europe, which is being installed in Rokkasho (Japan) with the purpose of validating the IFMIF accelerator design.
The beam generated by the LIPAc accelerator will be stopped by a copper cone (2.5 m long, 6.8° angle), cooled by water flowing at high velocity along its outer surface. This piece is surrounded by a shield made of iron and low Z materials for attenuating the neutron and gamma radiation originated by the interaction of the deuterons with the copper. It incorporates dedicated diagnostics for beam dump monitoring: accelerometers for detection of localized heating due to incorrect alignment of the beam and ionization chambers, which ensure that the deuteron beam footprint remains within the beam dump design limits.
A lead shutter has been designed to be inserted in the beam tube during beam-off periods to stop the gamma radiation from the activated copper cone escaping through the beam tube, allowing access inside the accelerator vault. The junction of the beam dump to the beam tube has a special design to allow its remote disconnection, enabling the end of life decommissioning operations of the facility. The design and material selection of the beam dump and neighboring elements are driven by a maintenance-free requirement after a short period of operations, as the cartridge activation precludes any maintenance activities in the beam dump and neighboring elements downstream the lead shutter.
This paper describes the design and manufacturing of the beam dump and related elements explaining the interrelations between them and the reasons behind their main features.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In light of the potential interest of Interdigital H-mode (IH) cavities for accelerating carbon ion beams beyond 5 MeV/u, we are reviewing the key geometric elements of the regular cells and end ...cells to optimize performance in terms of power efficiency, achievable voltage, and dipole field correction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Beam stripping losses of H- ion beams by interactions with residual gas and electromagnetic fields are evaluated. These processes play an important role in compact cyclotrons where the beam is ...produced on an internal ion source, and they operate under high magnetic field. The implementation of stripping interactions into the beam dynamics code OPAL provides an adequate framework to estimate the stripping losses for compact cyclotrons such as AMIT. The analysis is focused on optimizing the high energy beam current delivered to the target. The optimization is performed by adjusting parameters of the ion source to regulate the vacuum level inside the accelerator and minimize the beam stripping losses.
