ELECTRONIC STRUCTURE OF GE IN SIO2

It is argued that one-electron theory is insufficient to account for the origin of the observed spectra of Ge in SiO2 ( alpha -quartz) crystals. A simple model is employed to show that impurity states responsible for ESR spectra of SiO2:Ge are stabilised by many-electron polarisation effects associated with the Ge atom itself and its immediate oxygen neighbour

Preempting the Police

The challenge of regulating police discretion is exacerbated by the fact that a great deal of questionable police activity exists in the legal shadows—unregulated practices that do not violate defined legal limits because they have generally eluded both judicial and legislative scrutiny. Local law enforcement strategies, like the maintenance of unauthorized police DNA databases and the routine practice of initiating casual street encounters, threaten fundamental notions of a free society but have largely failed to elicit a judicial or legislative response. This Article argues that, instead of establishing a floor for impermissible police misconduct and then ceding responsibility to the legislative branch, state courts should become more interventionist—prodding legislators to provide greater guidance about police activities that they condone by forcing them to explicitly endorse questionable police practices. Accordingly, state courts should use the intrastate preemption doctrine, which holds that state law can supplant municipal authority, to find that local police officers may not engage in certain activities. Rather than stifle municipal policy innovation, a finding of preemption can precipitate a policy debate that engages both legislators and the electorate in evaluating police activity. This “information-forcing” approach can promote a more democratic dialogue about police practices, provide stronger protections for the community, and confer greater legitimacy on the police activities that legislators choose to sanction

Self Diagnostic Accelerometer for Mission Critical Health Monitoring of Aircraft and Spacecraft Engines

A self diagnostic accelerometer system has been shown to be sensitive to multiple failure modes of charge mode accelerometers. These failures include sensor structural damage, an electrical open circuit and most importantly sensor detachment. In this paper, experimental work that was performed to determine the capabilities of a self diagnostic accelerometer system while operating in the presence of various levels of mechanical noise, emulating real world conditions, is presented. The results show that the system can successfully conduct a self diagnostic routine under these conditions

Run Scenarios for the Linear Collider

Scenarios are developed for runs at a Linear Collider, in the case that there is a rich program of new physics.Comment: 12 pages, 10 tables, Latex; Snowmass 2001 plenary repor

Enhanced suppresion of localization in a continuous Random-Dimer Model

We consider a one-dimensional continuous (Kronig-Penney) extension of the (tight-binding) Random Dimer model of Dunlap et al. [Phys. Rev. Lett. 65, 88 (1990)]. We predict that the continuous model has infinitely many resonances (zeroes of the reflection coefficient) giving rise to extended states instead of the one resonance arising in the discrete version. We present exact, transfer-matrix numerical calculations supporting, both realizationwise and on the average, the conclusion that the model has a very large number of extended states.Comment: 10 pages, 3 Figures available on request, REVTeX 3.0, MA/UC3M/1/9

The Heavy Photon Search beamline and its performance

The Heavy Photon Search (HPS) is an experiment to search for a hidden sector photon, aka a heavy photon or dark photon, in fixed target electroproduction at the Thomas Jefferson National Accelerator Facility (JLab). The HPS experiment searches for the e$^+$e$^-$ decay of the heavy photon with bump hunt and detached vertex strategies using a compact, large acceptance forward spectrometer, consisting of a silicon microstrip detector (SVT) for tracking and vertexing, and a PbWO$_4$ electromagnetic calorimeter for energy measurement and fast triggering. To achieve large acceptance and good vertexing resolution, the first layer of silicon detectors is placed just 10 cm downstream of the target with the sensor edges only 500 $\mu$m above and below the beam. Placing the SVT in such close proximity to the beam puts stringent requirements on the beam profile and beam position stability. As part of an approved engineering run, HPS took data in 2015 and 2016 at 1.05 GeV and 2.3 GeV beam energies, respectively. This paper describes the beam line and its performance during that data taking