ERL2011 - List of Authors (Sawamura, M.)

Paper

Title

Page

Development of Input Coupler for Compact ERL Main Linac

91

H. Sakai, T. Furuya, N. Nakamura, M. Sato, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan
K. Shinoe
ISSP/SRL, Chiba, Japan

We fabricated the prototype of an input coupler, which has two ceramic windows to keep the inside of the superconducting cavity clean, for ERL main linac and performed the high power test. Required input power is about 20kW with standing wave condition for the cavity acceleration field of 20MV/m. In this high power test, the one ceramic window, named as a cold window, was installed into the vacuum insulating chamber and cooled by liquid Nitrogen. First, the multipacting at 10kW level prevented the power increasing. By using the pulse processing method for 8 hours, power finally reached the 25kW with standing wave condition. We could also keep feeding 20kW power into coupler for 16 hours. From these results of high power test, this prototype coupler satisfied our thermal and RF requirements.

Slides WG3006 [5.352 MB]

PSP021

Design of ERL Spoke Cavity for Non-destructive Assay Research

140

M. Sawamura
JAEA/ERL, Ibaraki, Japan
R. Hajima, R. Nagai, N. Nishimori
JAEA, Ibaraki-ken, Japan

We are proposing non-destructive assay system of nuclear materials with laser Compton scattering combined with an energy-recovery linac and a laser. To construct this system for nuclear safeguards and security purpose, it is important to make the accelerating cavity small. The spoke cavity has advantages over the elliptical cavity to adopt for our proposing system. We are designing a spoke cavity favorable to compact cavity. Design optimization calculation of the spoke cavity shape is being carried out using 3D electro-magnetic field simulation code with multi-objective genetic algorithm. The results will be presented.

WG3003

HOM Properties of Main Linac for cERL in Japan

87

M. Sawamura
Japan Atomic Energy Agency (JAEA), Gamma-ray Non-Destructive Assay Research Group, Tokai-mura, Ibaraki-ken, Japan
E. Cenni
Sokendai, Ibaraki, Japan
T. Furuya, H. Sakai, K. Umemori
KEK, Ibaraki, Japan
K. Shinoe
ISSP/SRL, Chiba, Japan

Two types of HOM absorber models were designed and fabricated. One type was almost actual shape except for HIP ferrite. The other was the center part of HOM absorber where ferrite was HIPped. Both models were used to estimate the cooling properties such as thermal conductivity and thermal cycle tolerance. The model with ferrite was also used to estimate the HOM absorption installing to the 9-cell cavity at the room temperature. The measured results will be presented.

Slides WG3003 [2.204 MB]

Paper	Title	Page
WG3006	Development of Input Coupler for Compact ERL Main Linac	91
	H. Sakai, T. Furuya, N. Nakamura, M. Sato, K. Umemori KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan K. Shinoe ISSP/SRL, Chiba, Japan
	We fabricated the prototype of an input coupler, which has two ceramic windows to keep the inside of the superconducting cavity clean, for ERL main linac and performed the high power test. Required input power is about 20kW with standing wave condition for the cavity acceleration field of 20MV/m. In this high power test, the one ceramic window, named as a cold window, was installed into the vacuum insulating chamber and cooled by liquid Nitrogen. First, the multipacting at 10kW level prevented the power increasing. By using the pulse processing method for 8 hours, power finally reached the 25kW with standing wave condition. We could also keep feeding 20kW power into coupler for 16 hours. From these results of high power test, this prototype coupler satisfied our thermal and RF requirements.
	Slides WG3006 [5.352 MB]

PSP021	Design of ERL Spoke Cavity for Non-destructive Assay Research	140
	M. Sawamura JAEA/ERL, Ibaraki, Japan R. Hajima, R. Nagai, N. Nishimori JAEA, Ibaraki-ken, Japan
	We are proposing non-destructive assay system of nuclear materials with laser Compton scattering combined with an energy-recovery linac and a laser. To construct this system for nuclear safeguards and security purpose, it is important to make the accelerating cavity small. The spoke cavity has advantages over the elliptical cavity to adopt for our proposing system. We are designing a spoke cavity favorable to compact cavity. Design optimization calculation of the spoke cavity shape is being carried out using 3D electro-magnetic field simulation code with multi-objective genetic algorithm. The results will be presented.

WG3003	HOM Properties of Main Linac for cERL in Japan	87
	M. Sawamura Japan Atomic Energy Agency (JAEA), Gamma-ray Non-Destructive Assay Research Group, Tokai-mura, Ibaraki-ken, Japan E. Cenni Sokendai, Ibaraki, Japan T. Furuya, H. Sakai, K. Umemori KEK, Ibaraki, Japan K. Shinoe ISSP/SRL, Chiba, Japan
	Two types of HOM absorber models were designed and fabricated. One type was almost actual shape except for HIP ferrite. The other was the center part of HOM absorber where ferrite was HIPped. Both models were used to estimate the cooling properties such as thermal conductivity and thermal cycle tolerance. The model with ferrite was also used to estimate the HOM absorption installing to the 9-cell cavity at the room temperature. The measured results will be presented.
	Slides WG3003 [2.204 MB]