RADIOCARBON IN MEXICO: FROM PROPORTIONAL COUNTERS TO AMS

ABSTRACT Augusto Moreno is credited with establishing the first radiocarbon (14C) laboratory in Mexico in the 1950s, however, 14C measurement with the accelerator mass spectrometry (AMS) technique was not achieved in our country until 2003. Douglas Donahue from the University of Arizona, a pioneer in using AMS for 14C dating, participated in that experiment; then, the idea of establishing a 14C AMS laboratory evolved into a feasible project. This was finally reached in 2013, thanks to the technological developments in AMS and sample preparation with automated equipment, and the backing and support of the National Autonomous University of Mexico and the National Council for Science and Technology. The Mexican AMS Laboratory, LEMA, with a compact 1 MV system from High Voltage Engineering Europa, and its sample preparation laboratories with IonPlus automated graphitization equipment, is now a reality.

RBS Channeling MATLAB Application for Automated Measurement Control and Evaluation for 6MV Tandetron Accelerator

Rutherford backscattering spectrometry (RBS) in channeling regimes (RBS/C), as an ion beam analysis method performed on a Tandetron 6MV accelerator, generally gives precise information about the structure of crystalline samples by combining RBS signals in the random and aligned configurations. This paper presents details about the design and implementation of tailored RBS/C measurements (coarse and fine) and data evaluation application developed in MATLAB for in situ accelerator control system ARGUS, delivered by High Voltage Engineering Europa BV (HVEE). Additionally, we examined two different ways of stepping during the measurement to reduce the possible inaccuracies related with goniometer’s backslash affecting the evaluation of spectra. Verification experiment was carried out using a 2-MeV 4He+-beam directed on a Si (100) substrate. The channeling effect is seen as channeling dips of a lower signal in an otherwise rather homogeneous plane. Implemented application significantly facilitates the RBS/C measurement and analysis of the experiments, and also extends the ion beam analysis portfolio of Advanced Technologies Research Institute. Finally, software is ready-to-use for any Tandetron based ion beam facility with the ARGUS software for accelerator control.

Nonlinear Electrical Conduction in Polymer Composites for Field Grading in High-Voltage Applications: A Review

Applications of polymeric materials in electrical engineering increasingly require improvements in operating voltages, performance, reliability, and size reduction. However, the resulting increase on the electric field in electrical systems can prevent achieving these goals. Polymer composites, functionalized with conductive or semiconductive particles, can allow us to reduce the electric field, thus grading the field within the system. In this paper, a comprehensive review of field-grading materials, their properties, and recent developments and applications is provided to realize high-performance high-voltage engineering applications.

Polyimide in Electronics: Applications and Processability Overview

Polyimides are nowadays quite famous dielectrics and insulating materials widely used in electronics and electrical engineering applications from low voltage microelectronics up to high voltage engineering industry. They are well appreciated because of their excellent physical properties (i.e., thermal, electrical, and mechanical properties), as well as, their coating process ease either from a liquid or a gas phase. Consequently, polyimides appear in a various range of applications to efficiently separate metal levels or electrodes at different electrical potentials. This chapter intends to review the main chemical generalities of polyimides, the different monomer families, the coating and curing processes, and the main physical properties for electronic and high voltage industrial applications.

The NRU MPEI Department of High Voltage Engineering and Electrophysics Turns 90

In 2021, the Department of High Voltage Engineering and Electrophysics, one of the oldest departments of the National Research University Moscow Power Engineering Institute, celebrates its 90-year anniversary. The article outlines the main stages of the department's life, areas of educational activity and research work related to improving the reliability and performance efficiency of high-voltage equipment at electrical substations and in power transmission lines. The main scientific results obtained in different years by the department specialists are presented, and their reflection in the educational process is shown. Special attention is paid to the establishment of the Problem Laboratory of Strong Electric Fields. The material presented in the article shows the great contribution made for the department by its heads: professors L.I. Sirotinsky, D.V. Razevig, V.P. Larionov, and I.P. Vereshchagin, who were the creators of the department and laid the spirit of creative approach to the problems solved both in the training of specialists and in scientific work, which distinguished the department throughout all 90 years of its existence.