IPAC2011 - List of Authors (Itoga, T.)

Paper	Title	Page
WEPC164	First Operation of a Fiber Beam Loss Monitor at the SACLA FEL	2367
	X.-M. Maréchal, T. Itoga JASRI/SPring-8, Hyogo, Japan Y. Asano RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.

Paper

Title

Page

First Operation of a Fiber Beam Loss Monitor at the SACLA FEL

2367

X.-M. Maréchal, T. Itoga
JASRI/SPring-8, Hyogo, Japan
Y. Asano
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

A fiber-based Cerenkov beam loss monitor (CBLM) has been developed as a quick and long-range detection tool for radiation safety at the X-ray FEL SACLA (SPring-8 angstrom compact free electron laser) to minimize electron beam losses. Based on tests carried out at the 250 MeV SPring-8 Compact SASE Source facility, large core (400 μm), long (>120 m) multimode fibers were selected and installed in the undulator section of SACLA. We report on the first few months of operation of the CBLM. During the commissioning of the X-FEL, the CBLM has performed effectively, with a detection limit below 10 pC per pulse across the 110 meters of the in-vacuum undulators, and with a position accuracy of less than 2 m. Experimental results are presented along with detailed numerical studies including the geometry of in-vacuum insertion devices, and discussed.