Conveners
Superconducting RF: 1
- Enrico Cenni
Superconducting RF: 2
- Yasuchika Yamamoto (KEK)
Superconducting RF: 3
- Sergey Belomestnykh
Superconducting RF: 4
- Dimitri Delikaris (CERN)
Superconducting RF: 5
- Daniele Sertore (INFN Milano - LASA)
Superconducting RF: 6
- Marc Wenskat (DESY)
We generalize a native Nb2O5 dissolution model [G. Ciovati, Appl. Phys. Lett. 89, 022507 (2006)] to sequential overlayer dissolutions, multilayer dissolution, and realistic temperature profiles, which may be applicable to other materials. The model is applied to secondary ion mass spectrometry depth profile measurements for varying temperature profiles and two-step oxide dissolution in Nb and...
IJCLab has been leading development and deployment of low-beta SRF cavities for proton and heavy ion accelerators.
We are launching a new project for sustainable Energy Recovery Linac (iSAS/PERLE) with state-of-the-art SRF cavities at 800 MHz.
Our proposal includes advanced heat treatment of such cavities to reach excellent quality factor at high fields.
In this talk, we overview the status...
We have the Cavity Fabrication Facility (CFF) at KEK. This facility was constructed to focus on the fabrication of SRF Nb cavities. Recently we fabricated one FG-Nb 9-cell cavity which complies with High Pressure Gas Safety code at CFF/KEK. We also are fabricating a 9-cell cavity with new Nb material, Medium-Grain (MG) Nb, which has the Nb grain size of sub-mm. The presentation reports the...
The Kyoto-KEK sX mapping system was applied to the vertical testing of a 805 MHz 6-cell SNS high-beta cavity (HB60) aimed at localizing field emitters in the cavity. The test result will be presented and implication to the on-going effort in the battle against field emission in current and future SRF cavities will be discussed.
In this contribution we report on the development of a cavity tuner for a cryomodule, which is being developed and will be built and tested in the scope of the International Linear Collider (ILC) Technology Network (ITN) at KEK until 2027. We have simulated Lorentz-force detuning of the according SRF 1.3 GHz 9-cell TESLA-type cavities to understand the tuner requirements better. As a base of...
At KEK, from FY2023, new 5-year plan for SRF technology development has started under MEXT-ATD program partly related to ITN. Power coupler is one of them, basically same as E-XFEL design. We chose the ceramics material developed by collaboration of KEK-KYOCERA. And, we changed some design from E-XFEL. We have done the RF simulation to evaluate the effect of these changes. In FY2024, we will...
The RF power distribution system for the International Linear Collider (ILC) is redesigned based on the updated requirements established in the scope of the ILC Technology Network (ITN) at KEK. Its main features are a low center of gravity, a compact design, and a reduced number of waveguide components. The power distribution system design is updated to avoid interference among various...
In complement to the development activities for fusion reactors (JT-60SA & ITER), Fusion for Energy contributes to the R&D for material characterisation facilities. Within the Broader Approach agreement, different actors from Europe to Japan collaborate to develop and assemble in Japan the LIPAC, a technical demonstrator of a D+ accelerator that will be used to produce neutron by nuclear...
SRF materials such as niobium have been extremely useful for accelerator technology but require low temperature operation ~4K. The development of high temperature superconductors (HTS) is promising due to their operating temperatures being closer to that of liquid nitrogen ~77K. This work hopes to determine the high-power RF performance of such materials at X-band (11.424 GHz). We have tested...
Conventional SRF cavities are used in standing wave regime and are limited by surface fields to ~50 MV/m. In order to overcome this limit, Superconducting Traveling Wave (SCTW) cavity was proposed as it allows to achieve ~1.5 times higher accelerating gradient operating at lower phase advance per cell, thus improving transit time factor. However, power recirculation through a feedback...
While a demonstration of TW resonance excitation in the 3-cell structure in 2K liquid helium had been prepared and carried out at Fermilab in collaboration with Euclid Techlabs, the RF design process of 0.5~1 meter scale TW cavity was begun at Fermilab as the next step of TW development towards an accelerator-scale one. Considering the physical dimensions of existing SRF facilities (for...
Several proposals of e+e- colliders with energy recovery
concept have been proposed in the last few years. I shall
discuss about possible upgrade of ILC in the far future
using energy recovery linacs.
As the part of research into the manufacturing methods for SRF cavities used in ILC(International Linear Collider), two 1.3 GHz single-cell cavities have been fabricated by utilizing fine and medium grain size niobium materials, respectively, with the same manufacturing equipment. The fine grain size niobium material typically exhibits a grain size level equivalent to ASTM 5-6, whereas the...
MEXT-ATD/ITN cavities will be fabricated under the high-pressrue gas safety (HPGS) act, refregeration safety regulations. Mechanical test for all the material and stress analysis of ITN/TESLA cavity were performed. Application documents are almost ready for submission. Presentation is given for the status of HPGS application, including proposal of cavity surface treatment.
ITN is an acronym for "ILC Technology Network".
It is an international framework for the technological development outlined in the Work Package(WP).
KEK plans to produce one cryomodule equipped with eight superconducting 9-cell cavities for WP1 and 2 from 2023 and perform performance measurements in 2027.
A test facility will be required to perform the measurements.
We are preparing the...
KEK is now constructing a cryomodule for 1.3 GHz TESLA cavities. Design of this cryomodule and the status of construction will be presented in this talk.
Cavities and cryomodules assembled at Fermilab have demonstrated unprecedented field emission (FE) free gradients. However, consistent FE-free performance is not guaranteed. Many lessons were learned, and continued vigilance is a must. In addition, several improvements have been identified to further push the state-of-the-art low particulate cavity processing and assembly at Fermilab. Those...
Robotic dust-free clean assembly is currently attracting worldwideใattention, and KEK has purchased a Fanuc CRX-20iA/L and is conducting R&D for its application to ILC type string assembly. The status of KEK'sใactivity on the robotics will be presented in the presentation.
Plasma processing stands as an in-situ technique for mitigating field emission and multipacting effects in the long-term operation of superconducting accelerating cavities. While extensively explored and applied to elliptical cavities, its application to quarter-wave resonators (QWRs) represents a relatively recent area of investigation. At IJCLab, ongoing efforts focus on refining plasma...
Since 2017, CEA has been developing the use of collaborative robots (cobot) to carry out the steps required to assemble superconducting cavities strings. This development is based on two main objectives. The first is to reduce the tediousness for operators of certain stages of component cleaning by blowing, so that they can focus on higher value-added tasks. The second is to improve assembly...
ESS is completing the installation of the first phase of the operation, which will start in the fall of 2024 on the partial beam dump and proceed with operation on the target in 2025, after receiving the intentional neutron production license from the authorities.
All modules (CM) for this operation phase, with an energy reach of 870 MeV and a power capability of 2 MW, will be tested by early...
The Mainz Energy-recovering Superconducting Accelerator (MESA), an energy-recovering (ER) LINAC, is currently under construction at the Institute for Nuclear physics at the Johannes Gutenberg-Universitรคt Mainz, Germany. In the ER operation mode, continuous wave (CW) beam is accelerated from 5 MeV up to 105 MeV. The energy gain of the beam is provided through 2 enhanced ELBE-type cryomodules...
Research and development on high-Q cavities requires extensive experimental campaigns to understand the origin of possible performance limitations and then to study the effect of more advanced surface treatments on the physical mechanisms governing such a high-Q operating regime.
From the experimental point of view, significant effort must be made to avoid flux trapping, either by canceling...
Energy saving is mandatory for new generation linacs and accelerators more generally. Cryogenics is one of the major energy costs in modern SRF accelerators because of the need to lower the operating temperature to 2K. Substituting Nb with a higher critical-temperature superconductor, such as Nb3Sn, allows operations to be moved up to 4.5 K with a reduction in cryogenic costs by a factor of 3....
Based on the success of the European XFEL srf cavity production, several projects worldwide (LCLS-2, SHINE, etc.) applied and further developed the underlying technology, specifically for cw application with higher Q-value and moderate operation gradients up to 21 MV/m. For a high-duty cycle (hcd) / cw upgrade of the European XFEL, it is required to preserve the high gradient operation in the...
