A cusp electron gun for millimeter wave gyrodevices

The experimental results of a thermionic cusp electron gun, to drive millimeter and submillimeter wave harmonic gyrodevices, are reported in this paper. Using a "smooth" magnetic field reversal formed by two coils this gun generated an annular-shaped, axis-encircling electron beam with 1.5 A current, and an adjustable velocity ratio alpha of up to 1.56 at a beam voltage of 40 kV. The beam cross-sectional shape and transported beam current were measured by a witness plate technique and Faraday cup, respectively. These measured results were found to be in excellent agreement with the simulated results using the three-dimensional code MAGIC

Confounded by the Field: Bidding in Food Auctions When Field Prices Are Increasing

Auction experiments are commonly used to determine consumers’ willingness to pay for various food items. While their non-hypothetical nature is a positive, market substitutes create a probable confounding of bids by field prices. This study examines the influence of field prices on bids for four foods in two versions by conducting auctions before and after large price increases in 2007. Results show that bids were capped at given field prices and were significantly higher in sessions conducted after store prices increased. Percentage premiums, however, were not significantly different across sessions, suggesting that effects of field prices could be reduced. Overall, researchers must be conscious of how field prices affect bids.auction experiments, field prices, organic, bidding, Consumer/Household Economics, Institutional and Behavioral Economics, Marketing,