Antonio Mogro-Campero

Radiation Belts of Jupiter: A Second Look

The outbound leg of the Pioneer 11 Jupiter flyby explored a region farther from the equator than that traversed by Pioneer 10, and the new data require modification or augmentation of the magnetodisk model based on the Pioneer 10 flyby. The inner moons of Jupiter are sinks of energetic particles and sometimes sources. A large spike of particles was found near lo. Multiple peaks occurred in the particle fluxes near closest approach to the planet; this structure may be accounted for by a complex magnetic field configuration. The decrease in proton flux observed near minimum altitude on the Pioneer 10 flyby appears attributable to particle absorption by Amalthea.

Indoor radon levels in the northeastern U.S.: effects of energy-efficiency in homes.

The expectation of elevated 222Rn levels in modern homes that have low air interchange rates with the out-of-doors caused us to survey both solar and conventional homes in northeastern New York State. The solar homes as a group have three times the 222Rn levels of the conventional homes, and specific problems exist that are introduced or exaggerated by modern construction. For example the highest two levels of radon in the solar homes give radiation doses over 30 yr that are known to produce lung cancer in 1% of uranium miners. Summer readings in more than half of the cases are different from winter ones by a factor of two or more, so that year-round measurements are necessary for precise dosimetry. The track etching technique is ideally suited for such measurements.

Comparison of high-temperature-superconductor and metal-based resonators

A 50- Omega coplanar waveguide (CPW) resonator designed for a fundamental frequency of about 4.75 GHz was fabricated on LaAlO/sub 3/. Two versions were fabricated: the first using 1.9- mu m-thick gold and the second using 0.6- mu m-thick YBa/sub 2/Cu/sub 3/O/sub 7/. The devices were identically packaged and tested at 77 K. It was found that the high-temperature superconductor (HTS) resonator had a surface resistance, R/sub s/, about six to nine times lower than the Au one. At 45 K, the R/sub s/ of the HTS resonator decreases by another factor of 4 compared with its 77 K value. Device characteristics for the HTS resonator are presented. >

Effects of space radiation on high-temperature superconducting thin films of YBa2Cu3O(7-x)

An investigation aimed at determining the effects of space radiation on superconducting materials and the possibility of simulating these effects with Co-60 gamma rays is briefly described. Data obtained indicate that the electron component of space radiation does not degrade the critical temperature of the YBCO films under consideration at least for energies around 800 keV. Exposure to Co-60 gamma rays in air for qualifying superconducting materials against the space radiation threat is considered to require some further investigation. 26 refs.

Search for Monopoles Above the 15-Foot Bubble Chamber

Magnetic monopoles having energies less than about 40 TeV will be slowed to their terminal velocity by the earths atmosphere. They may then be gathered by the fringing magnetic field of the 15-foot bubble chamber. We propose placing detectors of Lexan and nuclear emulsion at convenient locations above and below the bubble chamber. Such a systom would be sensitive to monopole masses between 10 GeV and 100 TeV and to monopole charges between {approx}0.7 and 10 hc/2e. The experiment would require the construction of a special light roof and would run for 5 weeks during a time when the bubble chamber is filled with air and not in use for other experiments. This study would lower the existing limit on in-flight detection of monopoles (at the earths surface) by a factor of 20.