Electrostatic potential distribution of the sunlit lunar surface

Electrostatic potential distribution on sunlit lunar surfac

Properties of lift-off structured high Tc microbridges

Microbridges and DC SQUIDs (superconducting quantum interference devices) were fabricated, using a lift-off technique, from RF sputtered YBaCuO films on MgO single-crystal substrates. Microwave measurements at 9 GHz on microbridges and the magnetic-field dependence of their critical current reveal wide bridge behaviour up to temperatures near the maximum operating temperature of the bridge. Mostly, a linear dependence of the critical current on the temperature is found, which is connected with high intrinsic 1/f noise if the bridge is constant-current-biased slightly above the critical current. In some bridges and DC SQUIDs, regimes with a temperature dependence proportional to (1-T/Tc)1.5 are found. In this case the 1/f noise level is much smaller and SQUID modulation can be followed to about 65

Experimental demonstration of a W-band gyroklystron amplifier

The experimental demonstration of a four cavity W-band (93 GHz) gyroklystron amplifier is reported. The gyroklystron has produced 67 kW peak output power and 28% efficiency in the TE011 mode using a 55 kV, 4.3 A electron beam. The full width at half maximum instantaneous bandwidth is greater than 460 MHz, a significant increase over the bandwidth demonstrated in previous W-band gyroklystron amplifier experiments. The amplifier is unconditionally stable at this operating point. Experimental results are in good agreement with theoretical predictions

Overcoming Overdisclosure: Toward Tax Shelter Detection

Every year, thousands of taxpayers and their advisors mail special disclosure forms that reveal details of potentially abusive tax strategies to the Office of Tax Shelter Analysis of the Internal Revenue Service in Ogden, Utah. The mandatory disclosure regime has been widely praised as one of the government\u27s most effective weapons in its war on tax shelters. In contrast to this largely positive portrayal, however, this Article argues that the current tax shelter disclosure law is incomplete. While the primary aim of current law is to deter non-disclosure of information by taxpayers and advisors, my claim is that the government should also strive to prevent behavior that may be just as problematic to the IRS\u27s ability to detect and challenge tax shelters - overdisclosure of information. As this Article demonstrates, since the introduction of the tax shelter reporting rules in 2000, taxpayers and advisors have frequently disclosed to the IRS their participation in routine, non-abusive transactions or details of activities that are irrelevant to tax shelter detection. After investigating the sources of overdisclosure, I conclude that the tax law itself invites this response from distinct types of taxpayers and advisors. Conservative types overdisclose out of excessive caution, while aggressive types overdisclose in an attempt to avoid detection of abusive tax planning. As a result of the threats to tax administration that overdisclosure poses, I offer three novel proposals for proactively reducing its occurrence: the introduction of anticipatory angel lists when the IRS designates new listed transactions; the enactment of targeted overdisclosure penalties; and a non-tax documentation requirement for business taxpayers

Superconducting Mg-B films by pulsed laser deposition in an in-situ two-step process using multi-component targets

Superconducting thin films have been prepared in a two-step in-situ process, using the Mg-B plasma generated by pulsed laser ablation. The target was composed of a mixture of Mg and MgB2 powders to compensate for the volatility of Mg and therefore to ensure a high Mg content in the film. The films were deposited at temperatures ranging from room temperature to 300 degrees C followed by a low-pressure in-situ annealing procedure. Various substrates have been used and diverse ways to increase the Mg content into the film were applied. The films show a sharp transition in the resistance and have a zero resistance transition temperature of 22-24 K.Comment: 4 pages, 3 figures, submitted to Applied Physics Letter