PAC2013 - Table of Session: THOBA (Contributed Oral Presentations, Accelerator Technology)

Paper

Title

Page

High-Gradient Metallic Photonic Band-Gap (PBG) Structure Breakdown Testing At 17 GHz

1088

B.J. Munroe, M.A. Shapiro, R.J. Temkin
MIT/PSFC, Cambridge, Massachusetts, USA

Funding: This work was supported by DOE, High Energy Physics, Grant No. DE-SC0010075.
Photonic Band-gap (PBG) structures continue to be a promising area of research for future accelerator structures. Previous experiments at X-Band have demonstrated that PBG structures can operate at high gradient and low breakdown probability, provided that pulsed heating is controlled. A metallic single-cell standing-wave structure has been constructed at MIT to investigate breakdown performance of PBG structures with very high surface temperature rise. The MIT standing-wave structure test stand has an available power of 4 MW for a maximum gradient of 130 MV/m; the actual realized gradient may be lower due to breakdown limitations. The MIT test stand will also utilize novel diagnostics, including fast camera imaging and optical spectroscopy of breakdowns.

Slides THOBA1 [2.078 MB]

THOBA2

First Cavity Results from the Cornell SRF Group's Nb3Sn Program

1091

S. Posen, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

As an alternative material for SRF accelerator cavities, Nb3Sn presents two important benefits. Its large Tc gives it a very small surface resistance, leading to a huge reduction in cooling costs; and its predicted Hsh of nearly 400 mT would allow for very high gradients and therefore fewer cavities in high energy linacs. Researchers in the Cornell SRF group have recently fabricated two 1.3 GHz cavities coated with Nb3Sn. Testing of these first cavities has produced encouraging results, including a very high Tc and some very high performing regions. These cavity results as well as new sample results under TEM will be presented.

Slides THOBA2 [4.880 MB]

THOBA3

Completion of the First SSR1 Cavity for PXIE and First Jacketed Tests

L. Ristori
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV to serve as a test beam for the Project X Injector Experiment (PXIE). The major goals of PXIE are the validation of the Project X concept and mitigation of technical risks. The SSR1 cryomodule comprises the last portion of PXIE and contains 8 SSR1 cavities operating at 325 MHz with an optimal beta of 0.22. In this paper we present the lessons learned from the completion of the first cavity including the welding operations necessary to install the Nb-SST transition ring and the SST helium jacket. The results of various tests on the jacketed resonator are also presented.

Slides THOBA3 [5.626 MB]

THOBA4

Development of Yb Laser For High Power Ultra-Short Pulse

1094

Y. Matsumura, K. Koyama
University of Tokyo, Tokyo, Japan
M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
M. Yoshida, X. Zhou
KEK, Ibaraki, Japan

Funding: A part of this research is sponsored by KAKENHI, Grants-in-Aid for Scientic Research(C)24510120.
Passively mode-locked Yb lasers can easily generate femtosecond pulse at high repetition rate. The Yb lasers also have a property of high efficiency, which enables us to obtain high power laser. Because of these characteristics, the Yb lasers have been applied to many fields such as optical frequency comb and X-ray generation. Now, femtosecond pulse of much higher energy at high repetition rate is being required for dielectric laser accelerator (DLA) and lasertron. We have developed high power mode-locked Yb laser, and achieved 20W mode-locked Yb fiber laser amplification system at repetition rate of 62MHz. At the conference, our latest results will be reported.

Slides THOBA4 [6.414 MB]

Paper	Title	Page
THOBA1	High-Gradient Metallic Photonic Band-Gap (PBG) Structure Breakdown Testing At 17 GHz	1088
	B.J. Munroe, M.A. Shapiro, R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA
	Funding: This work was supported by DOE, High Energy Physics, Grant No. DE-SC0010075. Photonic Band-gap (PBG) structures continue to be a promising area of research for future accelerator structures. Previous experiments at X-Band have demonstrated that PBG structures can operate at high gradient and low breakdown probability, provided that pulsed heating is controlled. A metallic single-cell standing-wave structure has been constructed at MIT to investigate breakdown performance of PBG structures with very high surface temperature rise. The MIT standing-wave structure test stand has an available power of 4 MW for a maximum gradient of 130 MV/m; the actual realized gradient may be lower due to breakdown limitations. The MIT test stand will also utilize novel diagnostics, including fast camera imaging and optical spectroscopy of breakdowns.
	Slides THOBA1 [2.078 MB]

THOBA2	First Cavity Results from the Cornell SRF Group's Nb3Sn Program	1091
	S. Posen, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	As an alternative material for SRF accelerator cavities, Nb3Sn presents two important benefits. Its large Tc gives it a very small surface resistance, leading to a huge reduction in cooling costs; and its predicted Hsh of nearly 400 mT would allow for very high gradients and therefore fewer cavities in high energy linacs. Researchers in the Cornell SRF group have recently fabricated two 1.3 GHz cavities coated with Nb3Sn. Testing of these first cavities has produced encouraging results, including a very high Tc and some very high performing regions. These cavity results as well as new sample results under TEM will be presented.
	Slides THOBA2 [4.880 MB]

THOBA3	Completion of the First SSR1 Cavity for PXIE and First Jacketed Tests
	L. Ristori Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV to serve as a test beam for the Project X Injector Experiment (PXIE). The major goals of PXIE are the validation of the Project X concept and mitigation of technical risks. The SSR1 cryomodule comprises the last portion of PXIE and contains 8 SSR1 cavities operating at 325 MHz with an optimal beta of 0.22. In this paper we present the lessons learned from the completion of the first cavity including the welding operations necessary to install the Nb-SST transition ring and the SST helium jacket. The results of various tests on the jacketed resonator are also presented.
	Slides THOBA3 [5.626 MB]

THOBA4	Development of Yb Laser For High Power Ultra-Short Pulse	1094
	Y. Matsumura, K. Koyama University of Tokyo, Tokyo, Japan M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan M. Yoshida, X. Zhou KEK, Ibaraki, Japan
	Funding: A part of this research is sponsored by KAKENHI, Grants-in-Aid for Scientic Research(C)24510120. Passively mode-locked Yb lasers can easily generate femtosecond pulse at high repetition rate. The Yb lasers also have a property of high efficiency, which enables us to obtain high power laser. Because of these characteristics, the Yb lasers have been applied to many fields such as optical frequency comb and X-ray generation. Now, femtosecond pulse of much higher energy at high repetition rate is being required for dielectric laser accelerator (DLA) and lasertron. We have developed high power mode-locked Yb laser, and achieved 20W mode-locked Yb fiber laser amplification system at repetition rate of 62MHz. At the conference, our latest results will be reported.
	Slides THOBA4 [6.414 MB]