Microwave Electronics

Contains reports on three research projects.Lincoln Laboratory (Purchase Order DDL-B222)United States Department of the ArmyUnited States Department of the NavyUnited States Department of the Air Force (Contract AF19(604)-5200

Improvements on the accuracy of beam bugs

At LLNL resistive wall monitors are used to measure the current and position used on ETA-II show a droop in signal due to a fast redistribution time constant of the signals. This paper presents the analysis and experimental test of the beam bugs used for beam current and position measurements in and after the fast kicker. It concludes with an outline of present and future changes that can be made to improve the accuracy of these beam bugs. of intense electron beams in electron induction linacs and beam transport lines. These, known locally as ''beam bugs'', have been used throughout linear induction accelerators as essential diagnostics of beam current and location. Recently, the development of a fast beam kicker has required improvement in the accuracy of measuring the position of beams. By picking off signals at more than the usual four positions around the monitor, beam position measurement error can be greatly reduced. A second significant source of error is the mechanical variation of the resistor around the bug

Concentration and δD of molecular hydrogen in boreal forests: Ecosystem-scale systematics of atmospheric H_2

We examined the concentration and δD of atmospheric H2 in a boreal forest in interior Alaska to investigate the systematics of high latitude soil uptake at ecosystem scale. Samples collected during nighttime inversions exhibited vigorous H_2 uptake, with concentration negatively correlated with the concentration of CO_2 (−0.8 to −1.2 ppb H_2 per ppm CO_2) and negatively correlated with δD of H_2. We derived H_2 deposition rates of between 2 to 12 nmol m^(−2) s^(−1). These rates are comparable to those observed in lower latitude ecosystems. We also derive an average fractionation factor, α = D:H_(residual)/D:H_(consumed) = 0.94 ± 0.01 and suggestive evidence that α depends on forest maturity. Our results show that high northern latitude soils are a significant sink of molecular hydrogen indicating that the record of atmospheric H_2 may be sensitive to changes in climate and land use

Plasma Electronics

Contains reports on five research projects.National Science Foundation (Grant GK-19)Lincoln Laboratory (Purchase Order DDL BB-107)U. S. Air Force (Contract AF 19(628)-500)U. S. Atomic Energy Commission (Contract AT(30-1)-3221)U. S. Atomic Energy Commission (Contract AT(30-1)-3285

Microwave Electronics

Contains research objectives and reports on three research projects.Department of the ArmyDepartment of the NavyDepartment of the Air Force under Contract AF19(122)-458U. S. Navy (Office of Naval Research) under Contract Nonr-1841(49)Lincoln Laboratory, Purchase Order DDL-B22