SRF2017 - List of Keywords (plasma)

Paper	Title	Other Keywords	Page
TUPB087	Low Temperature and Low Pressure Plasma for the HWR Superconducting Cavity In-situ Cleaning	ion, electron, cavity, experiment	595
	A.D. Wu, W. Chang, H. Guo, Y. He, C.L. Li, Y.M. Li, P.R. Xiong, L. Yang, W.M. Yue, S.H. Zhang, H.W. Zhao IMP/CAS, Lanzhou, People's Republic of China F. Gou Sichuan University, Chengdu, People's Republic of China
	The glow discharge for low temperature and low pressures plasma were utilized for the half-wave resonator (HWR) superconducting cavity in-situ cleaning. The plasma was on ignition of the Argon/Oxygen mixture atmosphere, which was under the low pressure of 0.5 to 5.0 Pascal. Driven by the RF power with the frequency of the cavity fundamental mode, the plasma showed the typical characteristic of the typical RF glow discharge, which the temperature of the electrons about 1eV that diagnosed by the optical emission spectrum. The experimental parameters for the discharge were optimized to obtain the uniform plasma distribution on the HWR cavity, including the RF power, the atmospheric pressure and the oxygen proportion. At last, the vertical cryogenic test was completed to investigate the impact of active oxygen plasma cleaning on the HWR cavity performance recovery, which contaminated by hydrocarbons. The test proves that the glow plasma clean can relieve the x-ray radiation which caused by the field electron emission effect.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB087
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TUPB098	The Effect of Process Parameters on the Surface Properties of Niobium During Plasma Etching	ion, cavity, experiment, SRF	628
	J.J. Peshl, S. Popović, L. Vušković ODU, Norfolk, Virginia, USA J. Upadhyay LANL, Los Alamos, New Mexico, USA A-M. Valente-Feliciano JLab, Newport News, Virginia, USA
	Funding: This work is supported by the Department of Energy, Grant DE-SC0014397. We have shown that plasma etching using an electronegative Ar/Cl2 discharge can effectively remove surface oxide layers on Nb samples as well as bulk Nb from single cell SRF cavities. With accelerating fields on the order of wet etching processes and a decrease in field emission the use of plasma assisted etching for bulk Nb processing is a worthwhile endeavor. We are presenting the surface properties of plasma etched Nb. Cavity grade Nb coupons were made by water jet cutting, and then polished to achieve surface roughness equivalent to electropolishing (<1 micron). The coupons were plasma etched while process parameters (rf power, gas pressure, temperature and DC bias voltage) are varied. These samples are placed on the inner surface of the cylindrical cavity to be etched. The experimental setup is similar to the single cell cavity plasma etching setup. Each sample is weighed and scanned before and after plasma processing with an AFM, SEM, and digital optical microscope that provide both atomic composition and surface roughness profiles. Comparing the scans allows us to make conclusions about the effect of each parameter on the surface roughness. J. Upadhyay et. al. 'Cryogenic rf test of the first plasma etched SRF cavity,' arXiv: 1605.06494 [physics.acc-ph] (2016).*
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB098
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THPB055	Plasma-enhanced ALD System for SRF Cavity	ion, cavity, niobium, SRF	870
	S. Kato, H. Hayano KEK, Ibaraki, Japan
	Funding: This work was supported by Photon and Quantum Basic Research Coordinated Development Program by MEXT and partly by JST-CREST. A remote PEALD (Plasma-enhanced Atomic Layer Deposition) system which would offer a high conformality and a low deposition temperature has been being developed for deposition of NbN on an SRF cavity. The deposition equipment consists of a deposition chamber, a remote plasma exciter, a precursor supply system, vacuum pumps, a quartz crystal microbalance (QCM) as a film growth rate meter, a detoxifying system and a safety system. An RF frequency of 13.56MHz was used for the inductively coupled plasma exciter of a reactant gas. The whole equipment is in a draft booth for operation safety. For ALD of an SRF cavity, the ALD system allows us to easily replace the deposition chamber with a single cell Nb cavity. The prepared precursors are tris[ethylmethylamido][tert-butylimido] niobium (TBTEMN) and trimethylaluminium (TMA). Ammonia, hydrogen and water are also prepared as reactants. We will report the ALD system design and result of the NbN deposition on sample coupons which are analysed with SEM, EDX and XPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB055
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Paper

Title

Other Keywords

Page

TUPB087

Low Temperature and Low Pressure Plasma for the HWR Superconducting Cavity In-situ Cleaning

ion, electron, cavity, experiment

595

A.D. Wu, W. Chang, H. Guo, Y. He, C.L. Li, Y.M. Li, P.R. Xiong, L. Yang, W.M. Yue, S.H. Zhang, H.W. Zhao
IMP/CAS, Lanzhou, People's Republic of China
F. Gou
Sichuan University, Chengdu, People's Republic of China

The glow discharge for low temperature and low pressures plasma were utilized for the half-wave resonator (HWR) superconducting cavity in-situ cleaning. The plasma was on ignition of the Argon/Oxygen mixture atmosphere, which was under the low pressure of 0.5 to 5.0 Pascal. Driven by the RF power with the frequency of the cavity fundamental mode, the plasma showed the typical characteristic of the typical RF glow discharge, which the temperature of the electrons about 1eV that diagnosed by the optical emission spectrum. The experimental parameters for the discharge were optimized to obtain the uniform plasma distribution on the HWR cavity, including the RF power, the atmospheric pressure and the oxygen proportion. At last, the vertical cryogenic test was completed to investigate the impact of active oxygen plasma cleaning on the HWR cavity performance recovery, which contaminated by hydrocarbons. The test proves that the glow plasma clean can relieve the x-ray radiation which caused by the field electron emission effect.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB087

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPB098

The Effect of Process Parameters on the Surface Properties of Niobium During Plasma Etching

ion, cavity, experiment, SRF

628

J.J. Peshl, S. Popović, L. Vušković
ODU, Norfolk, Virginia, USA
J. Upadhyay
LANL, Los Alamos, New Mexico, USA
A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA

Funding: This work is supported by the Department of Energy, Grant DE-SC0014397.
We have shown that plasma etching using an electronegative Ar/Cl2 discharge can effectively remove surface oxide layers on Nb samples as well as bulk Nb from single cell SRF cavities*. With accelerating fields on the order of wet etching processes and a decrease in field emission the use of plasma assisted etching for bulk Nb processing is a worthwhile endeavor. We are presenting the surface properties of plasma etched Nb. Cavity grade Nb coupons were made by water jet cutting, and then polished to achieve surface roughness equivalent to electropolishing (<1 micron). The coupons were plasma etched while process parameters (rf power, gas pressure, temperature and DC bias voltage) are varied. These samples are placed on the inner surface of the cylindrical cavity to be etched. The experimental setup is similar to the single cell cavity plasma etching setup. Each sample is weighed and scanned before and after plasma processing with an AFM, SEM, and digital optical microscope that provide both atomic composition and surface roughness profiles. Comparing the scans allows us to make conclusions about the effect of each parameter on the surface roughness.
J. Upadhyay et. al. 'Cryogenic rf test of the first plasma etched SRF cavity,' arXiv: 1605.06494 [physics.acc-ph] (2016).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB098

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPB055

Plasma-enhanced ALD System for SRF Cavity

ion, cavity, niobium, SRF

870

S. Kato, H. Hayano
KEK, Ibaraki, Japan

Funding: This work was supported by Photon and Quantum Basic Research Coordinated Development Program by MEXT and partly by JST-CREST.
A remote PEALD (Plasma-enhanced Atomic Layer Deposition) system which would offer a high conformality and a low deposition temperature has been being developed for deposition of NbN on an SRF cavity. The deposition equipment consists of a deposition chamber, a remote plasma exciter, a precursor supply system, vacuum pumps, a quartz crystal microbalance (QCM) as a film growth rate meter, a detoxifying system and a safety system. An RF frequency of 13.56MHz was used for the inductively coupled plasma exciter of a reactant gas. The whole equipment is in a draft booth for operation safety. For ALD of an SRF cavity, the ALD system allows us to easily replace the deposition chamber with a single cell Nb cavity. The prepared precursors are tris[ethylmethylamido][tert-butylimido] niobium (TBTEMN) and trimethylaluminium (TMA). Ammonia, hydrogen and water are also prepared as reactants. We will report the ALD system design and result of the NbN deposition on sample coupons which are analysed with SEM, EDX and XPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-THPB055

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)