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Title: Klystron Modulator Design for the Los Alamos Neutron Science Center Accelerator

Conference ·

This paper will describe the design of the 44 modulator systems that will be installed to upgrade the Los Alamos Neutron Science Center (LANSCE) accelerator RF system. The klystrons can operate up to 86 kV with a nominal 32 Amp beam current with a 120 Hz repetition rate and 15% duty cycle. The klystrons are a mod-anode design. The modulator is designed with analog feedback control to ensure the klystron beam current is flat-top regulated. To achieve fast switching while maintaining linear feedback control, a grid-clamp, totem-pole modulator configuration is used with an 'on' deck and an 'off' deck. The on and off deck modulators are of identical design and utilize a cascode connected planar triode, cathode driven with a high speed MOSFET. The derived feedback is connected to the planar triode grid to enable the flat-top control. Although modern design approaches suggest solid state designs may be considered, the planar triode (Eimac Y-847B) is very cost effective, is easy to integrate with the existing hardware, and provides a simplified linear feedback control mechanism. The design is very compact and fault tolerant. This paper will review the complete electrical design, operational performance, and system characterization as applied to the LANSCE installation.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
DOE/LANL
DOE Contract Number:
AC52-06NA25396
OSTI ID:
1044833
Report Number(s):
LA-UR-12-22438; TRN: US1203402
Resource Relation:
Conference: IEEE International Power Modulator Conference and High Voltage Workshop ; 2012-06-03 - 2012-06-07 ; San Diego, California, United States
Country of Publication:
United States
Language:
English