Bifocal: A Multifunctional, Next Generation Electrostatic Analyzer
Abstract
We describe the design and initial development of a next generation charged particle analyzer capable of taking both routine survey measurements and targeted high angular resolution measurements of the distribution. Space physics missions are constrained by both mass and power considerations. Each instrument on a spacecraft must maximize its usefulness while minimizing the drain on resources. The proposed Bifocal electrostatic analyzer fulfills this requirement by making both coarse and fine resolution in-situ electron measurements. Bifocal is a modified tophat analyzer with 2 sets of electrostatic deflectors which divide the entrance of the instrument into two distinct apertures. The top aperture makes fine measurements that allow a detailed look at fine-scale features of the plasma such as loss cones. The lower aperture makes coarse measurements. We performed extensive computer simulations to optimize the angular resolution of the Bifocal sensor. Following the optics, transmitted charged particles hit a microchannel plate (MCP) detector. Below the MCP's, Bifocal utilizes multiple imaging anodes to achieve fine azimuthal resolution. To optimize detection efficiency and imaging resolution, we performed simulations varying both voltage and distance between the MCP exit face and the anodes. Minimizing azimuthal resolution of the fine aperture will be achieved using imaging anodes. Each anode is divided into two different sections with multiple wedge electrodes, with each section attached to separate preamplifiers whose signals provide the inputs to a signal divider circuit. Using the normalized signal difference between the two parts of the circuit, Bifocal determines the azimuthal location of incident particles to high accuracy. We describe the results of initial design and testing of the preamplifier and divider circuitry.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSM51A2462A
- Keywords:
-
- 2194 Instruments and techniques;
- INTERPLANETARY PHYSICSDE: 2494 Instruments and techniques;
- IONOSPHEREDE: 2794 Instruments and techniques;
- MAGNETOSPHERIC PHYSICSDE: 7594 Instruments and techniques;
- SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY