Difference: FJPPLAccelerateurRD (10 vs. 11)

Summary:
We will test a new granular converter consisting of small tungsten spheres in a hybrid positron source configuration. The beam test is scheduled for the summer of 2014 or later at the KEK injector linac. We have already built the granular converters with four different thicknesses at LAL-Orsay for this experiment. The impinging electron with beam energy of 7-8 GeV and bunched charge of 1 nC is foreseen. In these beam tests, the observations of the temperature rise will be done, putting high-precision thermocouples on the exit face of the converter. Additional observations through infrared cameras are considered. The goal of this project is to evaluate the feasibility of this new granular converter toward the high intensity positron sources.

French members :
I. Chaikovska, X. Artru, D. Dauvergne, H. Guler, R. Chehab, M. Chevallier

Japanese members :
M. Satoh, K. Furukawa, T. Kamitani, F. Miyahara, T. Suwada, K. Umemori

References:
[1] Y. Uesugi et al., Nuclear Instrum. Methods B 319 (2014) 17-23.
[2] P. Sievers et al., "Granular Converter Test at KEK"; Presented at the 8-th POSIPOL Workshop (POSIPOL2013), Argonne National Lab., Argonne, IL, U.S.A., Sep. 4-6, 2013.

Summary :
Many developments on Input Power Couplers for superconducting LINAcs have been performed during the last few years at LAL (IN2P3), IRFU (CEA) and KEK. Different prototypes, pre-series and even serial couplers (XFEL case) have been manufactured and are undergoing validation processes. Collaboration between the three already mentioned institutes on Superconducting Power Couplers aims to enhance technical exchanges on design and experience feedbacks as they represent a great potential source of information, both for the current Power Coupler tests and future Couplers developments, especially for the large scale machines.
In the frame of this collaboration we will mainly focus on the issues we consider as very problematic because they are still partially based on qualitative specifications. Therefore, validation criteria and tests have to be carefully specified. Copper plating, cleaning and RF conditioning are the main emphasis of our studies.

French members :
H. Jenhani, C. Arcambal, S. Berry, G. Devanz, H. Guler, W. Kaabi

Japanese members :
E. Kako, T. Konomi, T. Shishido

References :
[1] W. Kaabi, “Power couplers for XFEL”, IPAC2013, Shanghai,China, WEPWO001.
[2] H. Jenhani, “Validation procedures for the IFMIF power coupler prototypes”, SRF2013, Paris, France, THP056.
[3] E. Kako, “High power tests of CW input couplers for CERL injector cryomodule”, IPAC2012, New Orleans, Louisiana, USA, WEPPC012.