SRF2015 - List of Keywords (emittance)

Paper	Title	Other Keywords	Page
THPB022	A Preliminary Design of a Superconducting Accelerating Structure for Extremely Low Energy Proton Working in TE210 Mode	cavity, proton, simulation, acceleration	1115
	Z.Q. Yang, X.Y. Lu, W.W. Tan, D.Y. Yang, J. Zhao PKU, Beijing, People's Republic of China
	For the application of high intensity continuous wave (CW) proton beam acceleration, a new superconducting accelerating structure for extremely low β proton working in TE210 mode has been proposed at Peking University. The cavity consists of eight electrodes and eight accelerating gaps. The RF frequency is 162.5MHz, and the designed proton input energy is 200keV. A peak field optimization has been performed for the lower surface field. The accelerating gaps are adjusted by phase sweeping based on KONUS beam dynamics. Solenoids are placed outside the cavity to provide transverse focusing. Numerical calculation shows that the transverse defocusing of the KONUS phase is about three times smaller than that of the conventional negative synchronous RF phase. The beam dynamics of a 10mA CW proton beam is simulated by the TraceWin code. The simulation results show that the beam’s size is under effective control. Both the simulation and the numerical calculation show that the cavity has a relatively high effective accelerating gradient of 2.6MV/m. Our results show that this new accelerating structure may be a possible candidate for superconducting operation at such a low energy range.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB057	ELBE SRF Gun II - Emittance Compensation Schemes	cathode, gun, focusing, SRF	1235
	H. Vennekate, A. Arnold, D. Janssen, P.N. Lu, P. Murcek, J. Teichert, R. Xiang HZDR, Dresden, Germany P. Kneisel JLab, Newport News, Virginia, USA
	In May 2014 the first SRF photo injector at HZDR has been replaced by a new gun, featuring a new resonator and cryostat. The intention for this upgrade has been to reach for higher beam energies, bunch charges and therefore an increased average beam current, which is to be injected into the superconducting, CW ELBE accelerator, where it can be used for multiple purposes, such as THz generation or Compton backscattering. Because of the increased bunch charge of this injector compared to its predecessor, it demands upgrades of the existing and/or novel approaches to alleviate the transverse emittance growth. One of these methods is the integration of a superconducting solenoid into the cryostat. Another method, the so called RF focusing, is realized by displacing the photo cathode's tip and retracting it from the last cell of the resonator. In this case, part of the accelerating field is sacrificed for a better focus of the electron bunch right at the start of its generation. Besides particle tracking simulations, a recent study, investigating on the exact position of the cathode tip with respect to the cell's back plane after tuning and cool down, has been performed.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB093	A 1.3 GHz Waveguide to Coax Coupler for Superconducting Cavities With a Minimum Kick	cavity, niobium, electron, dipole	1360
	J.A. Robbins, C. Egerer, R.G. Eichhorn, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Transversal forces as a result of asymmetric field generated by the fundamental power couplers have become a concern for low emittance beam in future accelerators. In pushing for smallest emittances, Cornell has finished a physics design for a symmetric coupler for superconducting accelerating cavities. This coupler consists of a rectangular waveguide that transforms into a coaxial line inside the beam pipe, eventually feeding the cavity. We will report on the RF design yielding to the extremely low transversal kick. In addition, heating, heat transfer and thermal stability of this coupler has been evaluated.
Export •	reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

THPB022

A Preliminary Design of a Superconducting Accelerating Structure for Extremely Low Energy Proton Working in TE210 Mode

cavity, proton, simulation, acceleration

1115

Z.Q. Yang, X.Y. Lu, W.W. Tan, D.Y. Yang, J. Zhao
PKU, Beijing, People's Republic of China

For the application of high intensity continuous wave (CW) proton beam acceleration, a new superconducting accelerating structure for extremely low β proton working in TE210 mode has been proposed at Peking University. The cavity consists of eight electrodes and eight accelerating gaps. The RF frequency is 162.5MHz, and the designed proton input energy is 200keV. A peak field optimization has been performed for the lower surface field. The accelerating gaps are adjusted by phase sweeping based on KONUS beam dynamics. Solenoids are placed outside the cavity to provide transverse focusing. Numerical calculation shows that the transverse defocusing of the KONUS phase is about three times smaller than that of the conventional negative synchronous RF phase. The beam dynamics of a 10mA CW proton beam is simulated by the TraceWin code. The simulation results show that the beam’s size is under effective control. Both the simulation and the numerical calculation show that the cavity has a relatively high effective accelerating gradient of 2.6MV/m. Our results show that this new accelerating structure may be a possible candidate for superconducting operation at such a low energy range.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB057

ELBE SRF Gun II - Emittance Compensation Schemes

cathode, gun, focusing, SRF

1235

H. Vennekate, A. Arnold, D. Janssen, P.N. Lu, P. Murcek, J. Teichert, R. Xiang
HZDR, Dresden, Germany
P. Kneisel
JLab, Newport News, Virginia, USA

In May 2014 the first SRF photo injector at HZDR has been replaced by a new gun, featuring a new resonator and cryostat. The intention for this upgrade has been to reach for higher beam energies, bunch charges and therefore an increased average beam current, which is to be injected into the superconducting, CW ELBE accelerator, where it can be used for multiple purposes, such as THz generation or Compton backscattering. Because of the increased bunch charge of this injector compared to its predecessor, it demands upgrades of the existing and/or novel approaches to alleviate the transverse emittance growth. One of these methods is the integration of a superconducting solenoid into the cryostat. Another method, the so called RF focusing, is realized by displacing the photo cathode's tip and retracting it from the last cell of the resonator. In this case, part of the accelerating field is sacrificed for a better focus of the electron bunch right at the start of its generation. Besides particle tracking simulations, a recent study, investigating on the exact position of the cathode tip with respect to the cell's back plane after tuning and cool down, has been performed.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THPB093

A 1.3 GHz Waveguide to Coax Coupler for Superconducting Cavities With a Minimum Kick

cavity, niobium, electron, dipole

1360

J.A. Robbins, C. Egerer, R.G. Eichhorn, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Transversal forces as a result of asymmetric field generated by the fundamental power couplers have become a concern for low emittance beam in future accelerators. In pushing for smallest emittances, Cornell has finished a physics design for a symmetric coupler for superconducting accelerating cavities. This coupler consists of a rectangular waveguide that transforms into a coaxial line inside the beam pipe, eventually feeding the cavity. We will report on the RF design yielding to the extremely low transversal kick. In addition, heating, heat transfer and thermal stability of this coupler has been evaluated.

Export •

reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)