Anticipated Signal Levels for the ESA and RPA
Abstract
The accelerator module is equipped with four electron guns and several detectors to monitor the electron beam produced by the guns. The guns will produce a nominal 3 keV, 40 ampere electron beam. For the beam to propagate, the return current must equal the beam current. There is no detailed model for the EXCEDE III return current, therefore, for these calculations the current is assumed to distribute itself isotropically and uniformally over the module. It is noted that recent data from tests on the accelerator module indicate that the return current may not be uniform. The accelerator module is 38 inches in diameter and 101.5 inches long. This corresponds to an average return current of 0.00043 a per sq cm. Two instruments are being provided by Visidyne to measure the current at the accelerator module. The two instruments are sensitive to different spectral regions of the backscattered electron distribution. The Electrostatic Analyzer (ESA) detects electrons having energies between 100 eV and 6000 eV; the Retarding Potential Analyzer (RPA) is sensitive to energies between zero and 100 eV. A schematic of the location of the ESA and RPA on the accelerator module is shown. (rh)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 24, 1989
- Accession Number
- ADA223228
Entities
People
- R. J. Rieder
- W. P. Reidy