Low- and intermediate-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>, 352 MHz superconducting half-wave resonators for high power hadron acceleration

The general steps for the fabrication of a copper prototype of 325 MHz coaxial half-wave resonator (HWR) with β = 0.21 are presented and discussed in this work. The main features for the control of the electromagnetic properties during the manufacturing process of HWR are described in detail. The resonant frequency sensitivity to the accelerating gap and to the cavity height were experimentally estimated. Bead-pull measurements were performed and the electric field distribution along the beam axis of the manufactured cavity was estimated. The features of the cavity’s response in the critical coupling regime are analyzed. The experimental concept of a slow frequency tuning system (FTS) based on the moving plungers is proposed and tested. The tuning sensibility is experimentally estimated. The measured results agree with the simulations quite well, and the sensitivity for a single plunger configuration Δ f / Δ L = + 13 kHz mm−1 is achieved. The dynamic properties and operation algorithm of the FTS are studied and experimentally investigated.

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“…The HWR-325 cavity was designed in classical coaxial HWR (figure 1(a)) configuration with integrated helium vessel [4,18].…”

Section: Cavity Designmentioning

confidence: 99%

“…The common construction and operation principles of coaxial HWRs are well-known [4][5][6][7][8] and these type of cavities are used in many accelerating complexes [9][10][11][12]. From the geometrical point of view, the HWR cavities are larger than the more compact quarter-wave resonators.…”

Section: Introductionmentioning

confidence: 99%

Control of electromagnetic properties during prototyping, fabrication and operation of low-β 325 MHz half-wave resonators

Bychanok¹,

Sukhotski²,

Huseu³

et al. 2021

J. Phys. D: Appl. Phys.

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“…Feasibility to operate an RFQ in CW mode thanks to a clever water cooling RF tuning approach demonstrated in LEDA's 8 m long RFQ in 1999 [81], and 3. Superconducting technologies for low-β beams of light particles in the late 00s [82] that overcame the inherent limitations of a DTL to run high currents due to the unavoidable losses in its narrow drift tubes, which becomes a technological showstopper. Today, 1.3 mA H + in CW through superconducting half-wave resonators (HWR) has been achieved in 2013 in Israel [83] and 10 mA in CW in 2015 in China [84].…”

Section: Accelerator Based Systemsmentioning

confidence: 99%

“…The original concept of LIPAc at the time of the approval of IFMIF/EVEDA conceived a DTL as accelerating structure from the 5 MeV output of the RFQ, but this structure exhibits technological barriers for high currents in CW driven by the narrow apertures of the drift tube. The invention of the superconducting cavities for light particles in the late 2000s [82] opened the door to new current performances promptly demonstrated in SARAF [83] and C-ADS [94] programs.…”

Section: Liquid Targetsmentioning

confidence: 99%

An assessment of the available alternatives for fusion relevant neutron sources

Knaster¹

2018

Nucl. Fusion

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The discovery of void swelling in neutron-irradiated stainless steels by Cawthorne and Fulton in 1966 showed that radiation effects would seriously affect the lifetime of fission reactors. A few years later, in the early 1970s, serious damage levels were observed in core components of the first commercial fission reactors that had been in operation for one decade. Driven by the harder neutron spectrum, the fusion community was impelled to explore the technical possibilities to make available a fusion relevant neutron source to anticipate the difficulties faced by the fission reactors community and ensure the long-term operation of a fusion reactor. In 1976, the conclusions of the first review published announced the assets and drawbacks of the different possibilities, which today despite the four decades passed and the sound technological advancements, continue being basically the same. A suitable neutron spectrum can be theoretically obtained both from plasma-based or accelerators based facilities with either gas, liquid or solids targets. Needed facilities performances, available irradiation volumes that the concept allow and cost are at stake. In the past, the cost of the most promising facility based on stripping the neutron from a deuteron on a lithium target was misleadingly peered with that of a fusion reactor. A tokamak with sufficient volume to irradiate equipment under fusion relevant conditions will be likely available in the future once commercial fusion reactors have become a reality; unfortunately, this concept does not match the needs timely, and is unrealistic w.r.t. its costs nowadays with worldwide efforts prioritizing ITER. In this article, we will focus on the technical aspects and assess the present maturity of different existing possibilities based on nowadays technologies to count with neutrons at a suitable flux and spectrum to characterize and qualify fusion materials to be timely ready with our world fusion roadmaps.

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“…Furthermore, the technological risks linked with the use of CW DTL in the beam nominal conditions were possibly higher than the superconducting choice driven by the growing maturity of the technology since a considerable experience in superconducting low-β (the ratio of particle speed to that of light) existed [41] for heavy ions since the 1990s. These operate in CW mode of the independently-phased superconducting cavity linac (ISCL) type, consisting of short (2-4) gaps, low frequency (<200 MHz) accelerating cavities, thus conceptually similar to the proposed IFMIF HWR linac (2-gap cavities at 175 MHz) [42,59]. In the existing machines, the most widely used resonator type is the quarter-wave resonator (QWR), preferred for its relatively low cost, easy mechanical assembly and high performance at low-β; however, a significant drawback of this structure is given by the asymmetry of its shape, which can cause undesired beam steering.…”

Section: The Accelerator Facilitymentioning

confidence: 99%

The accomplishment of the Engineering Design Activities of IFMIF/EVEDA: The European–Japanese project towards a Li(d,xn) fusion relevant neutron source

Knaster¹,

Ibarra

Abal

et al. 2015

Nucl. Fusion

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The International Fusion Materials Irradiation Facility (IFMIF), presently in its Engineering Validation and Engineering Desi gn Activities (EVEDA) phase under the frame of the Broader Approach Agreement between Europe and Japan, accomplished in summer 2013, on schedule, its EDA phase with the release of the engineering design report of the IFMIF plant, which is here described. Many improvements of the design from former phases are implemented, particularly a reduction of beam losses and operational costs thanks to the superconducting accelerator concept, the re-location of the quench tank outside the 1 2 × test cell (TC) with a reduction of tritium inventory and a simplification on its replacement in case of failure, the separation of the irradiation modules from the shielding block gaining irradiation flexibility and enhancement of the remote handling equipment reliability and cost reduction, and the water cooling of the liner and biological shielding of the TC, enhancing the efficiency and economy of the related sub-systems. In addition, the maintenance strategy has been modified to allow a shorter yearly stop of the irradiation operations and a more careful management of the irradiated samples. The design of the IFMIF plant is intimately linked with the EVA phase carried out since the entry into force of IFMIF/EVEDA in June 2007. These last activities and their on-going accomplishment have been thoroughly described elsewhere (Knaster J et al [19]), which, combined with the present paper, allows a clear understanding of the maturity of the European-Japanese international efforts. This released IFMIF Intermediate Engineering Design Report (IIEDR), which could be complemented if required concurrently with the outcome of the on-going EVA, will allow decision making on its construction and/or serve as the basis for the definition of the next step, aligned with the evolving needs of our fusion community.

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Low- and intermediate-β, 352 MHz superconducting half-wave resonators for high power hadron acceleration

Cited by 13 publications

References 3 publications

Control of electromagnetic properties during prototyping, fabrication and operation of low-β 325 MHz half-wave resonators

Control of electromagnetic properties during prototyping, fabrication and operation of low-β 325 MHz half-wave resonators

An assessment of the available alternatives for fusion relevant neutron sources

The accomplishment of the Engineering Design Activities of IFMIF/EVEDA: The European–Japanese project towards a Li(d,xn) fusion relevant neutron source

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