title: A tetrode based fast pulsed microwave source for electron cyclotron resonance breakdown experiments.
abstract: To study electron cylotron resonance (ECR) breakdown and afterglow plasma in an experimental linear plasma system, a pulsed microwave source with rapid rise and fall of microwave power is desired. A pulsed microwave source with fast rise and fall capability for ECR breakdown experiments has been designed and tested for performance in the system. A tetrode, controlled by a modulator card, is used as a fast switch to initiate microwave power from a conventional magnetron operating at 2.45 GHz. The typical rise time of microwave power is approximately 3 micros and a fall time of approximately 10 micros. Using this scheme in a realistic pulsed microwave source at 800 W power, ECR breakdown of neutral gas is achieved and the plasma delay and fall time are observed from the plasma density measurements using a Langmuir probe. The design details of the fast rise pulsed microwave source are presented in this article with initial experimental results.
authors.affiliation: Institute for Plasma Research, Bhat, Gandhinagar Gujarat - 382 428, India. vipin@csp.res.in
authors.forename: Vipin K
authors.initials: VK
authors.lastname: Yadav
authors.forename: K
authors.initials: K
authors.lastname: Sathyanarayana
authors.forename: D
authors.initials: D
authors.lastname: Purohit
authors.forename: D
authors.initials: D
authors.lastname: Bora