Radiofrequency system analysis of the Lewis cyclotron modification

Computer code for analyzing radio frequency system of modified cyclotro

Test results for 20-GHz GaAs FET spacecraft power amplifier

Test were conducted to measure the performance of the 20-GHz solid state, proof-of-concept amplifier. The amplifier operates over the 17.7 to 20.2-GHz frequency range and uses high power gallium arsenide field effect transistors. The amplifier design and test methods are briefly described. NASA and contractor performance data are compared

Evaluation of operational amplifier immunity by means of Weibull distribution

The immunity of operational amplifiers is a trend topic for electromagnetic compatibility EMC community. Radiofrequency interference is usually applied to the operation amplifier and the voltage offset is monitored as a parameter to evaluate the EMC degradation. However, this method does not provide enough information to know the probability of failure to electromagnetic interference of the devices. In this paper, an alternative statistical analysis based on the Weibull distribution is used to analyze the electromagnetic immunity performance of operational amplifiers under different frequency interferences and modulation index. The results confirm the feasibility of the Weibull distribution to evaluate the radiofrequency interference RFI behavior.Peer ReviewedPostprint (author’s final draft

Implementation and evaluation of simultaneous video-electroencephalography and functional magnetic resonance imaging

The objective of this study was to demonstrate that the addition of simultaneous and synchronised video to electroencephalography (EEG)-correlated functional magnetic resonance imaging (fMRI) could increase recorded information without data quality reduction. We investigated the effect of placing EEG, video equipment and their required power supplies inside the scanner room, on EEG, video and MRI data quality, and evaluated video-EEG-fMRI by modelling a hand motor task. Gradient-echo, echo-planner images (EPI) were acquired on a 3-T MRI scanner at variable camera positions in a test object [with and without radiofrequency (RF) excitation], and human subjects. EEG was recorded using a commercial MR-compatible 64-channel cap and amplifiers. Video recording was performed using a two-camera custom-made system with EEG synchronization. An in-house script was used to calculate signal to fluctuation noise ratio (SFNR) from EPI in test object with variable camera positions and in human subjects with and without concurrent video recording. Five subjects were investigated with video-EEG-fMRI while performing hand motor task. The fMRI time series data was analysed using statistical parametric mapping, by building block design general linear models which were paradigm prescribed and video based. Introduction of the cameras did not alter the SFNR significantly, nor did it show any signs of spike noise during RF off conditions. Video and EEG quality also did not show any significant artefact. The Statistical Parametric Mapping{T} maps from video based design revealed additional blood oxygen level-dependent responses in the expected locations for non-compliant subjects compared to the paradigm prescribed design. We conclude that video-EEG-fMRI set up can be implemented without affecting the data quality significantly and may provide valuable information on behaviour to enhance the analysis of fMRI data

Fifty years of the CERN Proton Synchrotron : Volume 2

This report sums up in two volumes the first 50 years of operation of the CERN Proton Synchrotron. After an introduction on the genesis of the machine, and a description of its magnet and powering systems, the first volume focuses on some of the many innovations in accelerator physics and instrumentation that it has pioneered, such as transition crossing, RF gymnastics, extractions, phase space tomography, or transverse emittance measurement by wire scanners. The second volume describes the other machines in the PS complex: the proton linear accelerators, the PS Booster, the LEP pre-injector, the heavy-ion linac and accumulator, and the antiproton rings.Comment: 58 pages, published as CERN Yellow Report https://cds.cern.ch/record/1597087?ln=e

Unclassified information list, 12-16 September 1966

Book and document information list - astrophysics, atmospherics, biology, nuclear physics, missile technology, navigation, electronics, chemistry, materials, mathematics, and other topic