相关论文: Cryogenic rf test of the first plasma etched SRF c…
An apparatus and a method are described for plasma etching of the inner surface of superconducting radio frequency (SRF) cavities. Accelerator SRF cavities are formed into a variable-diameter cylindrical structure made of bulk niobium, for…
Plasma based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. The development of the technology based on Cl2/Ar plasma etching has to address several crucial…
Field emission (FE) is one of the main limiting factors of superconducting radio-frequency (SRF) cavities operating in accelerators and it occurs whenever contaminants, like dust, metal flakes or even absorbates, are present on the surface…
Plasma processing of superconducting radio frequency (SRF) cavities has been an active research effort at Jefferson Lab (JLab) since 2019, aimed at enhancing cavity performance by removing hydrocarbon contaminants and reducing field…
Plasma processing of superconducting radio frequency (SRF) cavities has shown an improvement in accelerating gradient by reducing the radiation due to field emission and multipacting. Plasma processing is a common technique where the free…
In-situ plasma processing of superconducting radio frequency (SRF) cavities is a performance recovery technique used to mitigate the field emission limiting phenomenon. It has been proved very effective at major particle accelerator…
Plasma processing has been shown to help mitigate degradation of the performance of superconducting radio-frequency cavities, providing an alternative to removal of cryomodules from the accelerator for refurbishment. Studies of plasma…
We demonstrate practical accelerating gradients on a superconducting radiofrequency (SRF) accelerator cavity with cryocooler conduction cooling, a cooling technique that does not involve the complexities of the conventional liquid helium…
A muon collider or Higgs factory requires significant reduction of the six dimensional emittance of the beam prior to acceleration. One method to accomplish this involves building a cooling channel using high pressure gas filled radio…
A scalable mapping system for superconducting RF cavities is presented. Currently, it combines local temperature measurement with 3D magnetic field mapping along the outer surface of the resonator. This allows for the observation of dynamic…
Field emission is one of the factors that can limit the performance of superconducting radio frequency cavities. In order to reduce possible field emission in LCLS-II (Linac Coherent Light Source II), we are developing plasma processing for…
Traveling wave SRF cavity is a new technology and requires a multi-stage process for development. Conceptual designs have been proposed to adopt TW resonance in an SRF cavity The early stages of developments have been funded by several SBIR…
Plasma cleaning is a technique that can be applied in superconducting radio-frequency (SRF) cavities in situ in cryomodules in order to decrease their level of field emission. We developed the technique for the Linac Coherent Light Source…
Improvement in SRF accelerator performance after in-tunnel plasma processing has been seen at SNS and CEBAF. Plasma processing development for FRIB quarter-wave and half-wave resonators (QWRs, HWRs) was initiated in 2020. Plasma processing…
Under-vacuum low- and mid-temperature baking revealed beneficial effects on the performance of niobium-made cavities for superconducting radio-frequency (SRF) applications, primarily seen in particle accelerators. Such a baking process is…
Processes occurring in a radio-frequency (rf) cavity, filled with high pressure gas and interacting with proton beams, have been studied via advanced numerical simulations. Simulations support the experimental program on the hydrogen…
The paper evaluates the thermal regime of a cryogenically cooled copper photocathode integrated into a continuous-wave superconducting radio-frequency injector cavity with direct thermal contact. Such a photoinjector layout is being…
The Pulsed RF Heating (PRFH) is the well known effect in the development of high gradient accelerating cavities. There is a lot of research dedicated to the tolerable strength of electromagnetic field and the corresponding temperature rise…
The understanding of the Ar/Cl2 plasma etching mechanism is crucial for the desired modification of inner surface of the three dimensional niobium (Nb) superconductive radio frequency cavities. Uniform mass removal in cylindrical shaped…
As progress towards real implementations of cryogenic high gradient normal conducting accelerating cavities continues, a more mature understanding of the surface physics in this novel environment becomes increasingly necessary. To this end,…