PAC2013 - List of Authors (Kinross-Wright, J.)

Paper	Title	Page
WEPHO11	Components of Heating and Fueling of Fusion Plasmas	954
	J. Kinross-Wright, M.P.J. Gaudreau, F.M. Niell, K. Schrock, B.E. Simpson Diversified Technologies, Inc., Bedford, Massachusetts, USA
	Funding: Work supported by the US Department of Energy under contract DE-SC00004250 Next generation fusion facilities will require many megawatts of RF power from dozens of gyrotrons. Each gyrotron requires a power system that must deliver the high-voltage power, modulate cathode voltage, and protect these expensive gyrotrons from arcing damage. It must be highly efficient, to minimize both the power and cooling costs associated with operation and to ensure high facility availability. Diversified Technologies, Inc. (DTI) has bench-tested a table-top scale ‘Buck Matrix’ modulator which uses a single set of IGBT switches for voltage regulation, arc protection, and pulse modulation. Although pulse step modulators represent a one-step solution, their size, and the complexity of their driving transformer make them more expensive than DTI’s two-step approach. DTI’s Buck Matrix modulator, with an efficiency of ~96%, cuts the size of the system in half, using a single layer of solid state switches for both voltage regulation and arc protection/modulation. This cuts the total hardware costs by a~30% or more, and eliminates the need for a separate opening switch or crowbar. DTI will present the system components of the design as well as the performance results to date.

THPBA11	A Stripline Kicker Driver for the Next Generation Light Source	1250
	N. Butler, M.P.J. Gaudreau, M.K. Kempkes, J. Kinross-Wright, F.M. Niell Diversified Technologies, Inc., Bedford, Massachusetts, USA
	Funding: Work supported by the US Department of Energy under grant DE-SC00004255 Diversified Technologies, Inc. (DTI) is developing a driver for a kicker strip-line deflector which inserts and extracts charge bunches to and from the electron and positron damping rings of the ILC. The ILC damping ring kicker driver must drive a 50 Ω load at 10kV with 2 ns flat-topped pulses, which is to burst pulses at a 3 MHz rate within 1 ms bursts occurring at a 5 Hz rate. The driver must also absorb high-order mode signals emerging from the deflector. Key components include: HV MOSFET switch array capable of delivering 25 ns, 400 A, 1kV pulses at 3 MHz in 1 ms bursts, at a burst rate of 5 Hz; this switch array having a withstand capability of 4kV+; DSRD diode stack capable of withstanding 5kV upon opening (but later 10kV), able to open within 500 ps and interrupt 400 A reverse current; a 1 ns 50 Ω delay line, together with an input circuit that presents a near-short to the line for frequencies greater than 10 MHz. DTI has demonstrated a solid state kicker driver meeting ILC requirements, extendable to a wide range of kicker driver applications. The MOSFET array switch, without the DSRDs, is itself suitable for many accelerator systems with >10 ns kicker requirements.

Paper

Title

Page

Components of Heating and Fueling of Fusion Plasmas

954

J. Kinross-Wright, M.P.J. Gaudreau, F.M. Niell, K. Schrock, B.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: Work supported by the US Department of Energy under contract DE-SC00004250
Next generation fusion facilities will require many megawatts of RF power from dozens of gyrotrons. Each gyrotron requires a power system that must deliver the high-voltage power, modulate cathode voltage, and protect these expensive gyrotrons from arcing damage. It must be highly efficient, to minimize both the power and cooling costs associated with operation and to ensure high facility availability. Diversified Technologies, Inc. (DTI) has bench-tested a table-top scale ‘Buck Matrix’ modulator which uses a single set of IGBT switches for voltage regulation, arc protection, and pulse modulation. Although pulse step modulators represent a one-step solution, their size, and the complexity of their driving transformer make them more expensive than DTI’s two-step approach. DTI’s Buck Matrix modulator, with an efficiency of ~96%, cuts the size of the system in half, using a single layer of solid state switches for both voltage regulation and arc protection/modulation. This cuts the total hardware costs by a~30% or more, and eliminates the need for a separate opening switch or crowbar. DTI will present the system components of the design as well as the performance results to date.

THPBA11

A Stripline Kicker Driver for the Next Generation Light Source

1250

N. Butler, M.P.J. Gaudreau, M.K. Kempkes, J. Kinross-Wright, F.M. Niell
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: Work supported by the US Department of Energy under grant DE-SC00004255
Diversified Technologies, Inc. (DTI) is developing a driver for a kicker strip-line deflector which inserts and extracts charge bunches to and from the electron and positron damping rings of the ILC. The ILC damping ring kicker driver must drive a 50 Ω load at 10kV with 2 ns flat-topped pulses, which is to burst pulses at a 3 MHz rate within 1 ms bursts occurring at a 5 Hz rate. The driver must also absorb high-order mode signals emerging from the deflector. Key components include: HV MOSFET switch array capable of delivering 25 ns, 400 A, 1kV pulses at 3 MHz in 1 ms bursts, at a burst rate of 5 Hz; this switch array having a withstand capability of 4kV+; DSRD diode stack capable of withstanding 5kV upon opening (but later 10kV), able to open within 500 ps and interrupt 400 A reverse current; a 1 ns 50 Ω delay line, together with an input circuit that presents a near-short to the line for frequencies greater than 10 MHz. DTI has demonstrated a solid state kicker driver meeting ILC requirements, extendable to a wide range of kicker driver applications. The MOSFET array switch, without the DSRDs, is itself suitable for many accelerator systems with >10 ns kicker requirements.