Publications (12)
LCLS-II-HE verification cryomodule high gradient performance and quench behavior
S. Posen, A. Cravatta, M. Checchin +43
An 8-cavity, 1.3 GHz, LCLS-II-HE cryomodule was assembled and tested at Fermilab to verify performance before the start of production. Its cavities were processed with a novel nitr…
Performance Enhancement of Medium-Temperature Baked Niobium SRF Cavity by Surface Contamination Removal
V. Chouhan, D. Bice, A. Cravatta +5
Medium temperature (mid-T) baking, typically conducted at 300 350 C, enhances the quality factor of niobium (Nb) superconducting radio frequency cavities. High vacuum furnace bakin…
Latest Development of Electropolishing Optimization for 650 MHz Niobium Cavity
V. Chouhan, D. Bice, D. Burk +15
Electropolishing (EP) of 1.3 GHz niobium superconducting RF cavities is conducted to achieve a desired smooth and contaminant-free surface that yields good RF performance. Achievin…
200 MV Record Voltage Of vCM And LCLS-II-HE Cryomodules Production Start At Fermilab
T. Arkan, J. Kaluzny, D. Bafia +11
The Linac Coherent Light Source (LCLS) is an X-ray science facility at SLAC National Accelerator Laboratory. The LCLS-II project (an upgrade to LCLS) is in the commissioning phase;…
Fermilab experience of post-annealing losses in SRF niobium cavities due to furnace contamination and the ways to its mitigation: a pathway to processing simplification and quality factor improvement
A. Grassellino, A. Romanenko, A. Crawford +10
We investigate the effect of high temperature treatments followed by only high-pressure water rinse (HPR) of superconducting radio frequency (SRF) niobium cavities. The objective i…
Accelerating fields up to 49 MV/m in TESLA-shape superconducting RF niobium cavities via 75C vacuum bake
A. Grassellino, A. Romanenko, D. Bice +9
In this paper we present the discovery of a new surface treatment applied to superconducting radio frequency (SRF) niobium cavities, leading to unprecedented accelerating fields of…
Improving the performance of mid-T baked niobium cavities through post-bake surface treatment
V. Chouhan, D. Bice, A. Cravatta +7
The 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).…
Excellent performance of 650 MHz single-cell niobium cavity after electropolishing
V. Chouhan, D. Bice, A. Cravatta +6
Electropolishing process and cathodes have undergone modification and optimization for both low- and high-beta 650 MHz five-cell niobium cavities for PIP-II. Cavities treated with…
Visual, Optical and Replica Inspections: Surface Preparation of 650 MHz NB Cavity for PIP-II Linac
V. Chouhan, D. Bice, D. Burk +2
Surface preparation of niobium superconducting RF cavities is a critical step for achieving good RF performance under the superconducting state. Surface defect, roughness, and cont…
The Evaluation of Mechanical Properties of LB650 Cavities
J. Holzbauer, G. Wu, H. Park +13
The PIP-II project's LB650 cavities could potentially be vulnerable to mechanical deformation because of the geometric shape of the cavity due to reduced beta. The mechanical prope…
Study on Electropolishing Conditions for 650 MHz Niobium SRF Cavity
V. Chouhan, D. Bice, F. Furuta +8
The PIP II linear accelerator includes different types of niobium SRF cavities including 650 MHz elliptical low (0.61) and high (0.92) beta cavities. The elliptical cavity surface…
Unprecedented Quality Factors at Accelerating Gradients up to 45 MV/m in Niobium Superconducting Resonators via Low Temperature Nitrogen Infusion
A. Grassellino, A. Romanenko, Y. Trenikhina +9
We report the finding of new surface treatments that permit to manipulate the niobium resonator nitrogen content in the first few nanometers in a controlled way, and the resonator…