WEAK-BEAM PHASE-BRIDGE MEASUREMENT OF INTERACTION IMPEDANCE
Abstract
A weak electron beam is operated at full circuit voltage to perturb the phase delay along a slow-wave structure. The beam current is typically on the order of one-thirtieth of Kompfner-dip current or backward-wave startoscillation current. The phase perturbation is measured on a simple phase bridge made of ordinary standing-wave-measurement equipment. The circuit-interaction impedance is calculated from this datum. Space-charge effects can be neglected without error. Since the beam is a velocity-sensitive perturbation, it can distinguish between different space-harmonic waves, between backward and forward waves, and between modes on some multimode circuits. Circuits intended for pulsed high-power operation can be perturbed with d-c beams without exceeding their dissipation ratings. Weak-beam data are compared favorably with forward-wave and backward-wave impedance data taken by the conventional methods on a tape helix. The weak-beam data are probably more reliable because of the lack of space-charge effects. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 29, 1960
- Accession Number
- AD0269309
Entities
People
- D.a. Dunn
- P.a. Brennan
- R.p. Lagerstrom
Organizations
- Stanford University