Title :
Development of a fast traveling-wave beam chopper for the National Spallation Neutron Source
Author :
Kurennoy, Sergey S. ; Jason, Andrew J. ; Krawczyk, Frank L. ; Power, John
Author_Institution :
Los Alamos Nat. Lab., NM, USA
Abstract :
High current and severe restrictions on beam losses, below 1 nA/m, in the designed linac for the National Spallation Neutron Source (NSNS) require clean and fast-with the rise time from 2% to 98% less than 2.5 ns to accommodate a 402.5-MHz beam structure-beam chopping in its front end, at the beam energy 2.5 MeV. The R&D program includes both modification of the existing LANSCE coax-plate chopper to reduce parasitic coupling between adjacent plates, and development of new traveling-wave deflecting structures, in particular, based on a meander line. Using analytical methods and three-dimensional time-domain computer simulations we study transient effects in such structures to choose an optimal chopper design
Keywords :
beam handling equipment; ion accelerators; ion optics; linear accelerators; neutron sources; 2.5 MeV; 2.5 ns; 402.5 MHz; H; H- linac; LANSCE coax-plate chopper; National Spallation Neutron Source; beam losses; beam structure; fast traveling-wave beam chopper; meander line; optimal chopper design; parasitic coupling; three-dimensional time-domain computer simulations; transient effects; traveling-wave deflecting structures; Choppers; Coaxial cables; Laboratories; Linear particle accelerator; Neutrons; Optical modulation; Pulse modulation; Pulse width modulation; Space vector pulse width modulation; Voltage;
Conference_Titel :
Particle Accelerator Conference, 1997. Proceedings of the 1997
Conference_Location :
Vancouver, BC
Print_ISBN :
0-7803-4376-X
DOI :
10.1109/PAC.1997.753400
