Alien Registration- Prest, Sidney G. (Bridgewater, Aroostook County)

https://digitalmaine.com/alien_docs/25966/thumbnail.jp

Enhanced velocity overshoot and transconductance in Si/Si(0.64)Ge(0.36)/Si pMOSFETs - predictions for deep submicron devices

No abstract avaliable

Experimental evidence of planar channeling in a periodically bent crystal

The usage of a Crystalline Undulator (CU) has been identified as a promising solution for generating powerful and monochromatic $\gamma$-rays. A CU was fabricated at SSL through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities

A compact light readout system for longitudinally segmented shashlik calorimeters

The longitudinal segmentation of shashlik calorimeters is challenged by dead zones and non-uniformities introduced by the light collection and readout system. This limitation can be overcome by direct fiber-photosensor coupling, avoiding routing and bundling of the wavelength shifter fibers and embedding ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present the first experimental test of this readout scheme performed at the CERN PS-T9 beamline in 2015 with negative particles in the 1-5~GeV energy range. In this paper, we demonstrate that the scheme does not compromise the energy resolution and linearity compared with standard light collection and readout systems. In addition, we study the performance of the calorimeter for partially contained charged hadrons to assess the $e/\pi$ separation capability and the response of the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,

Low-noise monolithic bipolar front-end for silicon drift detectors

Abstract A very low noise, 32-channel preamplifier/shaper chip has been designed for the analogue readout of silicon detectors. The circuit has been optimized in view of the operation of silicon drift detectors, which have very low capacitance and produce gaussian signals of σ of few tens of ns. The chip (OLA) has been designed and manufactured using the SHPi full-custom bipolar process by Tektronix. Each channel is composed by a preamplifier, a shaper and a symmetrical line driver, which allows to drive either a positive and a negative single ended output separately on 50 Ω impedance or a differential twisted pair. The intrinsic peaking time of the circuit is ∼60 ns , and the noise is below 250 electrons at zero input load capacitance. The power consumption is 2 mW/channel, mostly due to the output driver

Effective mobilities in pseudomorphic Si/SiGe/Si p-channel metal-oxide-semiconductor field-effect transistors with thin silicon capping layers

The room-temperature effective mobilities of pseudomorphic Si/Si0.64Ge0.36/Si p-metal-oxidesemiconductor field effect transistors are reported. The peak mobility in the buried SiGe channel increases with silicon cap thickness. It is argued that SiO2/Si interface roughness is a major source of scattering in these devices, which is attenuated for thicker silicon caps. It is also suggested that segregated Ge in the silicon cap interferes with the oxidation process, leading to increased SiO2/Si interface roughness in the case of thin silicon caps