A new cryogenic facility for the RF testing of thin film coated SRF cavities has been designed and built at Daresbury Laboratory. This facility uses a pulse-tube cryocooler providing 2.7 W of cooling power at 4.2 K and enables cavity tests at: 1.3, 3, 6 GHz. The cryostat has been constructed and has successfully passed initial vacuum and cryogenic tests. The primary focus of this facility is...
Within the ITN (ILC Technology Network) activity led by KEK, the so-called "Medium Grain Niobium" is investigated with respect to its possible application for a large-scale SRF cavity production for the International Linear Collider ILC [1-3]. In the framework of the KEK-DESY collaboration, the niobium material for two 1.3 GHz single-cell cavities was supplied by KEK. After fabrication and...
Additive Manufacturing (AM) offers a unique way of fabricating components with intricate geometries and enables the use of materials that are otherwise difficult to machine or process due to high melting points. Within this context, recent work at INFN-LNL and INFN-Padova focused on the fabrication of a seamless 6 GHz copper cavity using AM techniques. This study investigates the feasibility...
In complement to the development activities for fusion reactors (JT-60SA & ITER), Fusion for Energy contributes to the R&D for material characterisation facilities. The LIPAc, technical demonstrator for the production and acceleration of a D+ beam, will be used for neutron production by nuclear stripping reaction on a liquid Li target. Since its first beam in 2014, the LIPAc construction and...
In this work a method to include the effects of beam loading in FEM solvers for electromagnetic problems, such as CST and HFSS, is considered. The method involves using transmission line models of a beam-loaded and beamless resonant cavity to determine an effective surface resistance and tuning angle for the beamless cavity to produce the same reflection as the beam-loaded case. The cavity,...
RAON is a heavy ion accelerator consisting of a cryomodule containing a superconducting cavity in the SCL3 section and a warm section with a quadrupole magnet and a diagnostic chamber. Two types of superconducting RF cavities are utilized, arranged in three types of cryomodules: the 81.25 MHz quarter-wave resonator (QWR) and the 162.5 MHz half-wave resonator (HWR). In 2024, beam commissioning...
Accurate monitoring of beam dynamics in superconducting linear accelerators (linacs) is important for minimizing beam losses and maintaining stable operation. In superconducting sections, however, destructive diagnostics must be avoided to prevent issues such as particulate contamination and outgassing, which makes direct beam envelope measurements particularly difficult. This work introduces...
During vacuum commissioning and operation of large superconducting accelerators, gas flow may induce the dust particle within pipelines, causing intolerable particulate contamination in superconducting radio frequency (SRF) cavities. Investigating the transport behavior of microscale solid particles within accelerator pipelines is critical for understanding and solving particulate...
Crystal defects, such as dislocations and low-angle boundaries, provide sources of magnetic flux trapping in the Nb materials used for superconducting radio frequency (SRF) resonating cavities. Improving the performance of SRF cavities, as measured through the quality factor, requires reducing these defects. SRF cavity production involves deformation processing, such as rolling and forming,...
Recent advances in additive manufacturing promise interesting possibilities for the design and fabrication of superconducting radio frequency (SRF) cavities. Cold Spray Additive Manufacturing (CSAM) is one candidate that would allow for rapid built times, realization of integral cooling structures, deposition of different materials and an easy upscaling with available equipment. As it is the...
Superconducting QUantum Interference Devices (SQUID)s are superconducting loops broken by one or more Josephson junctions and act as RLC circuits with a resonant frequency that can be tuned by an applied magnetic field. A microwave metamaterial can be created by positioning many of these SQUIDs in an array such that such that their spacing is much less than that of the microwave wavelength. In...
The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018 and will deliver 10 low-beta cryomodules as In-Kind Contributions to the PIP-II project, with cavities supplied by LASA-INFN (Italy) and VECC-DAE (India), and...
In 2020, IHEP-CAS built a dual-vacuum furnace specifically used for Nb3Sn evaporation coating experiments. After four years of use and more than 80 experiments, in August 2024, it was found that the coated cavity produced by this furnace had serious field emission. After discussion and analysis, we suggested that the contamination originated from the coating furnace. By disassembling the inner...
The new "β-SRF" facility at TRIUMF allows for the near surface characterizations of materials with β-radiation-detected nuclear magnetic resonance (β-NMR) in applied magnetic fields up to 200 mT parallel to the sample surface. The unique facility can probe the local magnetic field within the first 100 nm of the surface and allows , for example, to measure the evolution of the Meissner...
This work presents a state-of-the-art design of a Ferroelectric Fast-Reactive Tuner (FE-FRT), capable of modulating high reactive power in TESLA type cavities on a microsecond time scale. The Mainz Energy-Recovering Superconducting Accelerator employs superconducting radio frequency cavities operating at 1.3 GHz, achieving quality factors on the order of 10^10. However, detuning of +/-25 Hz...
1.3 GHz 3-cell superconducting cavities were proposed for the injector of the high-brightness free electron laser based on energy recovery linac scheme. The average beam current is 10 mA and injector energy is 10 MeV. The beam tube of the cavity is enlarged to damp higher-order modes (HOMs) and to keep beam stability. Three cavities have been fabricated. An intrinsic quality factor of 2.0 ×...
The Institute of High Energy Physics (IHEP) developed the 1.5 GHz high -order harmonic cavity system for the Hefei Advanced Light Facility (HALF) project. This paper primarily introduces the design and development of the 1.5 GHz high-order harmonic superconducting cavity and cryomodule. The structure of the harmonic cavity has been simplified, and an integral welding method for the cavity with...
IJCLab has been contributing to several SRF accelerators in the world (SPIRAL2, ESS, PIP-II) and in particular was in charge of the design, surface preparation and qualification in vertical cryostat of low beta (i.e. complex 3D shape) resonators as Quarter-Wave Resonators (QWR) and Spoke Resonators. One of the main challenges of these complex geometries is the final surface cleaning by High...
The introduction of thin film structures into superconducting cavities is theoretically predicted to improve performance, and experimental verification is now required. In this study, we are developing a relatively small and easy-to-handle niobium-made 3 GHz single-cell cavity to verify the effects of introducing thin film structures. We performed vertical measurements on the 3 GHz single-cell...
Electropolishing (EP) is a critical process for achieving high quality factors (Q) and high accelerating gradients in superconducting radiofrequency (SRF) cavities. Despite its importance, the chemical mechanisms of EP remain unclear. Two primary models have been proposed: the viscous boundary layer theory, which attributes polishing to the formation of a viscous, HF-depleted boundary layer,...
Bulk Nb superconducting radio-frequency (SRF) cavities are widely utilized in particle accelerators, however, their accelerating gradient and overall performance are limited by the superheating field (Bs). To overcome this theoretical limit, we aim to develop innovative multilayer structures. Iron-based superconductors are considered promising coating materials for such multilayer structures,...
Superconducting thin film (TF) technology for Superconducting readio-frequency(SRF) applications is under intense development in many research centres around the world. TF SRF technology can not only drastically reduce cryogenic costs but also opens the door to simplified alternative cooling schemes with reduced helium inventory. Up to today, TF development have been considered within two High...
Recent advancements in Nb₃Sn cavity development have enabled the design of SRF accelerators utilizing compact mechanical cryocoolers instead of helium liquefiers, simplifying system architecture and reducing costs. In this background, our company has released a high-efficiency, high-capacity 4 K GM-JT (Gifford-McMahon-Joule-Thomson) cryocooler system with 10 W-class cooling capacity at 4.2 K....
Superconductor MgB2 has a Tc of 40 K, and its materials parameters suggest that SRF cavities with higher Q, higher gradient, and higher operation temperatures than Nb cavities can potentially be made from MgB2. We present our ongoing efforts towards the development of MgB2-coated SRF cavities. Thick MgB2 films, up to 5 um in thickness, were deposited onto 1.3 GHz Tesla-type copper RF cavities...
Japan Atomic Energy Agency (JAEA) has been proposing an accelerator-driven nuclear transmutation system (ADS) as a future nuclear system to efficiently reduce high-level radioactive waste generated at nuclear power plants. As the first step toward the full-scale CW proton linac for the JAEA-ADS, we are currently prototyping a low-beta (around 0.2) single-spoke cavity. Because there is no...
FRIB has developed a high Q 0.53HWRs within a DOE R&D program titled Development of Transformative Preparation Methods to Push up High Q&G Performance of FRIB Spare HWR Cryomodule Cavities. In this study, we found that flux trapping produces 80 % of the residual surface resistance (Rres). The main contribution is that from thermoelectric current produced by Seebeck effect (Dynamical magnetic...
Experimental evidence of parasitic radiation originating from cavity field emission or beam losses and interacting with cryomodule diagnostics has been collected.
We focus on the case of spurious triggering of power coupler interlock system which is based on the light detection of arcs and its transmission in optical fibers. Scenario of radiation interaction are modeled using Geant4, aiming...
The Mainz Energy-Recovering Superconducting Accelerator is currently under construction at the Institute for Nuclear Physics on the campus of the Johannes Gutenberg University Mainz. A future upgrade is planned for the multi-turn Energy Recovery (ER) mode, increasing the beam current from 1 mA to 10 mA in continuous wave at 1.3 GHz. Simulations have calculated an increased power deposition of...
Oak Ridge National Laboratory (ORNL) is in the process of upgrading its Spallation Neutron Source (SNS) Linear Accelerator in order to double the total machine power from 1.4 to 2.8 MW. This Proton Power Upgrade (PPU) makes use of an added 7 4-cavity cryomodules to its SRF Linac to raise the machine energy to a total 1.3 GeV (with one additional module produced as a ready spare). Jefferson Lab...
The fabrication of Superconducting Radio Frequency (SRF) cavities traditionally relies on forming and welding high-purity metal sheets, resulting in a local surface discontinuity that degrades the final SRF performance. In this work, we propose and explore a novel hybrid approach combining Wire Laser Additive Manufacturing (WLAM), with in situ CNC machining for the fabrication of mono-cell 1.3...
Recent advances in understanding the subsurface microstructure and microchemistry of niobium (Nb) have led to significant improvements in the quality factor (Q0) of superconducting radiofrequency (SRF) cavities. Beyond traditional surface treatments, emerging evidence highlights the critical role of the bulk microstructure, particularly in influencing the trapping and expulsion of residual...
Measuring cavity quality factors in a cryomodule requires calorimetric techniques because of the heavy input overcoupling. This involves using physical parameters of the cryogenic system such as mass flow, bath pressure, helium liquid level to estimate dynamic heat load of SRF cavities, often calibrated with heaters. The main challenges of these techniques are reducing sources of variation and...
Medium temperature (mid-T) baking of niobium superconducting radio-frequency cavities at 300–350 °C in a vacuum furnace is known to enhance the quality factor (Q₀). However, despite this improvement, cavities treated with this process often prematurely quench at relatively low accelerating fields. This limitation is suspected to arise from the formation of surface contaminants, such as niobium...
Superconducting–Insulating–Superconducting (SIS) multilayers offer a promising approach to surpass the accelerating gradients and quality factors of standard bulk-Nb SRF cavities†. Plasma-enhanced atomic layer deposition (PEALD) stands out as a key technique for the next-generation thin-film-based SRF cavities, providing conformal coatings on highly structured, three-dimensional substrates...
During the preparation for the installation of the LCLS-II HE cryomodules, one previously qualified cryomodule experienced an uncontrolled vacuum event. The cavity string vacuum unexpectedly increased to 2 × 10^ (-3) Torr. Simulation showed the vacuum incident may have introduced 0.1 μm sized particulates into the cavity RF volume. Careful analysis of the particulates' path and migration...
At FREIA, Uppsala (Sweden), an investigation of the Magnetic Field (MF) evolution during cool-down / warm-up cycles of 352 MHz single spoke cavities for the MINERVA proton linac (Phase I of the MYRRHA project) has been carried out: bulk-Nb SRF cavities equipped each with a dedicated MINERVA cavity magnetic shield (MGS) made of CRYOPHY® material have been measured during their testing in the...
Three superconducting linear accelerators are under construction at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS). 96 superconducting radio frequency (SRF) cavities housed in 17 cryomodules were fabricated, preparation and installed in the accelerator tunnel in 14 months. The cold test of the SRF cavity and cryomodule is skipped due to our excellent...
Minimizing residual magnetic fields during SRF cavity cooldown is essential for reducing surface resistance and improving the quality factor. At LASA-INFN, we implemented an active compensation system using Helmholtz-like coils in vertical test cryostats. The setup is optimized to reduce the average magnetic flux through the cavity surface by accounting for the spatial inhomogeneity of the...
The sensitivity of the surface resistance of SRF cavities depends on several aspects, such as the specific surface and heat treatment of the cavity. The the cooldown dynamics as the cavity transitions into the superconducting (sc) state also influence the performance if there is an external magnetic field. Both temperature gradient across the cavity and speed of the superconducting front have...
During last few years, an extensive efforts for obtaining Q0 vs Eacc characteristic of SRF cavities at very low accelerating gradients have been conducted in several laboratories around the world. In the Accelerator Module Test Facility (AMTF) at DESY, several attempts of such measurements were performed, mainly focused on the comparison between the widely used decay measurements technique and...
Residual magnetization of ferromagnetic coldmass components located near superconducting RF (SRF) cavities poses a significant threat to cavity performance, especially when a magnetic source, such as a focusing lens, is in close proximity. Previous work evaluated several passive mitigation techniques, including the use of local magnetic shields, and quantified both the residual fields induced...
Traveling-Wave (TW) technology can push the accelerator field gradient of niobium SRF cavity to 70 MV/m or higher beyond the fundamental limit of 50~60 MV/m in Standing-Wave regime. The success of TW resonance excitation in a proof-of-principle 3-cell SRF cavity in 2 K liquid helium encouraged to advance TW technologies necessary more for future accelerator-scale one. Fermilab has proposed a...
Niobium (Nb) has long been recognized as the primary material for superconducting radio-frequency (SRF) cavities due to its excellent superconducting properties and mechanical formability. However, improving its structural stability under cryogenic operating conditions and high electromagnetic loads remains a key challenge. In this study, we employ molecular dynamics (MD) simulations to...
STFC has built new infrastructure to enable particulate control whilst building superconducting radio frequency cavity string and beam line assemblies that can be used in high beta cryomodule applications. The new facility includes an ISO4 cleanroom, low particulate high pressure rinse, and most recently, a nitrogen purge system that can allow varying and controlled purge of nitrogen through...
The Proton Improvement Plan - II (PIP-II) project at Fermi National Accelerator Laboratory (Fermilab) is the first U.S. accelerator initiative to include major in-kind contributions (IKC) from international partners. As part of the French contribution, the French Alternative Energies and Atomic Energy Commission (CEA) will deliver ten 650 MHz low-beta (LB650) cryomodules. These cryomodules...
Positron annihilation spectroscopy (PAS) is a powerful and precise tool to study atomic-scale defects in a wide range of materials, especially superconductors. The PAS methods available at the user facility radiation source ELBE (HZDR, Germany) enable analysis of point defects and their agglomerations including within the range of micro- and mesopores. The extended defects and their complexes...
Picosecond-long X-ray pulses of moderate intensity and high repetition rate are highly sought after by the light source community, especially for time-resolved fine spectroscopic analysis of matter in the linear response regime. We investigate the upgrade of the Elettra 2.0 diffraction-limited storage ring light source to radiofrequency transverse deflecting superconducting cavities generating...
In the Shenzhen Superconducting Soft X-ray Free Electron Laser (S3FEL), Continuous Wave (CW) Low-Level Radio Frequency (LLRF) systems perform critical functions including adjusting the power coupling of accelerator cavities, regulating the amplitude and phase of the RF field, and maintaining the resonance frequency and phase of the cavities. These functions are essential to ensure the electron...
High gradient CW electron guns are essential for high-repetition-rate, high-brightness electron beams, key to advanced light sources and other applications. Compared to DC guns and normal conducting VHF guns, SRF guns are considered the next-generation solution for further boosting CW gun acceleration capabilities and electron source brightness. This paper presents the initial physics design...
The High-Luminosity Large Hadron Collider (HL-LHC) project is to increase the integrated luminosity by a factor of 10 beyond the LHC’s design value. TRIUMF is collaborating with CERN, UK and US-AUP to provide five RF dipole (RFD) crab cavity cryomodules to HL-LHC as Canadian contribution. A prototype cryomodule (TCM0) is being assembled to qualify TRIUMF’s infrastructure, procedure and...
Quality factor (Q) of SRF cavities is one of the essential parameters in continuous wave accelerator operation. Q degradation has been observed in the operation of ISAC-II superconducting heavy ion linac. Other than the well-known mechanisms, such as field emission and trapped magnetic flux, the past eight years statistics reveals gas molecules in the beam line caused measurable Q drops after...
RaSTA, the Rapid Superconductor Test Apparatus, is a sample test cavity project at HZB. It shares the sample geometry and the calorimetric measurement principle with the QPR but is targeted at quicker turnaround times and a more compact footprint at higher operating frequency. RaSTA 2.0 features a niobium coated copper cavity allowing for higher RF field levels and better thermal stability....
Time-dependent Ginzburg-Landau (TDGL) numerical simulations can capture vortex nucleation and motion, as well as proximity effects, at high frequencies in superconductors.† We use TDGL to study the nucleation of RF semi-loop vortices in Niobium in the presence of surface defects when the material is subjected to an intense RF magnetic field arising from a near-field microwave frequency dipole...
High acceleration gradients Eacc and high quality factors Q0 can be achieved by heat treatments of the cavity [1]. However, the heating processes are carried out in furnaces where the cavity is forcibly exposed to air afterwards, which can lead to contamination. For moderate temperatures (T < 350 °C), this issue could be overcome by in-situ heating. A few studies on in-situ heating have...
A new superconducting (sc) continuous-wave (cw) linear accelerator (linac) is currently being built at GSI to meet the future requirements in research on superheavy elements (SHE) synthesis and material science with a particular focus on fusion studies. The HElmholtz LInear Accelerator (HELIAC) will provide ion beams in the energy range from 3.5 MeV/u to 7.3 MeV/u with a mass-to-charge ratio...
In continuous mode operation, performance of normal-conducting copper RF cavities is limited by high power dissipation around 100 kW/m, needed there for achieving a modest 2 MV/m gradient. In contrast, superconducting RF (SRF) cavities can easily exceed 15 MV/m under similar conditions due to nominal Ohmic losses, thus making them ideal for high-duty accelerators like SNS and ADSS.
We are...
As part of the Quantum Technology Initiative (QTI) at CERN, a programme to develop a novel SRF cavity for axion searches has been launched. This Axion Detector Demonstrator (QTI_ADD) is based on the heterodyne approach to axion detection, and uses a dedicated SRF cavity design with overlapping, quasi-degenerate modes to search for axion-induced photon conversion from a driven, resonant cavity...
Sideband excitations observed in superconducting radio-frequency (SRF) cavities during vertical tests are indicative of complex underlying phenomena that can impact cavity performance and their measurements. This work presents an analysis combining experimental data and numerical simulations to investigate the origins and contributions of multipactor and field emission to sideband generation....
This contribution provides an updated overview of the Mainz Energy-Recovering Accelerator (MESA), a continuous-wave superconducting electron linac currently under construction at the Institute for Nuclear Physics at Johannes Gutenberg University Mainz. Designed to deliver high-current, highly polarized beams with energy recovery, MESA aims to support a diverse experimental program. The current...
The VSR cavities, featuring protruding waveguides and HOM absorbers, are designed to be installed as part of the cold string in a spaceframe within a cryogenic vessel. Precise alignment of the cavities during installation and continuous position monitoring during operation are required to prevent damage of other cold string components such as bellows. To achieve this, strain gauges are...
The Helmholtz Linear Accelerator HELIAC is a superconducting (sc) continuous wave linear accelerator for heavy ions currently under development at GSI in Darmstadt. However, single cavity tests and the majority of cleanroom activities took and still take place at the designated facilities of the Helmholtz Institute Mainz (HIM). Each of the sc cryomodules of the HELIAC houses 3 crossbar...
Mid-T heat treatment promotes the dissolution of surface native niobium oxide into bulk niobium and increases the interstitial oxygen concentration in the near surface layer of niobium, resulting in an improved quality factor for niobium SRF cavities at moderate accelerating fields. This study examines the average interstitial oxygen concentration within the effective magnetic field...
Currently, 1.3 GHz Nb superconducting elliptical cavities have achieved accelerating gradients of Eacc ≈ 40 MV/m. In contrast, theoretical predictions suggest that accelerating cavities with multilayer thin-film structures on their inner surfaces might reach gradients of Eacc ≈ 100 MV/m. Such significant performance improvements would represent a major advancement not only in high-energy...
Since the second half of 2022, the design of the CSNS-II elliptical cavities was completed and their manufacturing was initiated. After nearly three years of research, we have successfully developed three prototype elliptical cavities. Vertical tests demonstrated a maximum gradient of 25.7 MV/m, significantly surpassing the operational requirement of 14 MV/m. This achievement has laid a solid...
FLEXTAI LTD is located in Shenyang Economic and Technological Development Zone, Liaoning Province, China. It is the first Sino-foreign joint venture in China specializing in the production of metal corrugated pipe series products. The company mainly engages in the design, development and manufacture of metal bellows, metal bellows expansion joints, metal hoses, precision bellows and pipeline...
The consistent production of high-RRR Nb cavities for superconducting radiofrequency applications is critical to advancements in accelerator performance and technology. Despite standard guidelines for material and cavity production, the properties and performance of these cavities can vary significantly. Improvements in cavity performance due to better flux expulsion are observed after heat...
The ability to accurately and consistently quantify the recrystallized (Rx) microstructure of heat-treated high-purity Nb used in superconducting radiofrequency (SRF) applications is critical for the improvement of material processing and cavity production. The production of SRF cavity half-cells by deep-drawing Nb sheets into the half-cell geometry results in different stain paths in...
The Advanced Rare Isotope Laboratory (ARIEL) at TRIUMF will utilize a high-power electron beam to produce radioactive ion beams through photo-fission. Currently, the 30 MeV section of the ARIEL electron linear accelerator (e-Linac)—a 1.3 GHz superconducting RF (SRF) system—includes the injector cryomodule (ICM), which houses a single nine-cell cavity, and the first accelerator cryomodule...
The CSNS-II superconducting Linac accelerator includes 20 sets of 324 MHz superconducting spoke cavities and 24 sets of 648 MHz superconducting ellipsoidal cavities. The 324 MHz/300 kW solid-state power source supplies RF power to superconducting spoke cavity, while the 648 MHz/1.2 MW klystron power source supplies RF power to superconducting ellipsoid cavity. The 324 MHz/300 kW solid-state...
While the fabrication technology superconducting Niobium cavities is advanced, a wide gap exist between the theoretical threshold field $H_{sh}$ and the observed values. The reasons behind this discrepancy continue to pose intriguing questions, highlighting the need for further investigation. While material properties undoubtedly influence performance, we believe that the intricate dynamics of...
Thermal shrink of materials is always an obstacle when designing cryogenic systems. In superconducting cavity cryomodules, some adopt reference bars, which are made by Invar, to keep cavities’ position same at cryogenic temperature from room temperature. Linear expansion of Invar from 300 K to 2 K is about 0.04 %, resulting in approximately 5 mm of thermal shrink for the 12.6 m ILC cryomodule,...
The fabrication of SRF cavities from sheet materials includes deep-drawing, electron beam welding, chemical and mechanical polishing, high-temperature heat treatment, and material diffusion. The performance of these cavities is frequently constrained by magnetic flux trapping. In this presentation, we thoroughly examine how recrystallization influences flux expulsion in SRF cavities, using...
A novel vertical test facility (VTF) has been in operation at the UKRI-STFC Daresbury Laboratory since 2019. This VTF tests jacketed SRF cavities in a horizontal configuration at 2 K. Originally designed and operated for 704 MHz high-beta cavities for ESS, the facility has now been upgraded and expanded to test 650 MHz high-beta cavities for PIP-II, including fast cooldown capability (>20...
Compared to normal-conducting accelerators, superconducting linacs require a dramatically larger number of parameters to be monitored, including not only RF power and beam-related signals, but also cryogenic conditions such as helium tank pressure, vacuum levels, and cavity temperatures. This increased complexity demands robust and flexible monitoring systems, especially during extended...
Burst-noise events are primary trip sources at the China Accelerator Facility for superheavy Elements (CAFE2), characterized by a rapid burst noise in the cavity pick-up signal categorizable into three distinct types: flashover, electronic quench (E-quench), and partial E-quench. Herein, we design an algorithm identifying the burst-noise event types in real time to realize a real-time...
STFC Daresbury Laboratory recently completed the build of a Radio Frequency Dipole (RFD) crab cavity cryomodule prototype for the Super Proton Synchrotron (SPS), and the Double Quarter Wave (DQW) series build is currently underway. A key challenge was the leak testing of 34 unique weld configurations which could not be tested in the typical evacuation method.
A suite of 3D printed weld...
