Determination of Beam Orientation of Optical Diagnostics of Excited 200- MeV Hydrogen Atoms Resulting From Photodetachment of H-Ions
Abstract
Nondestructive diagnostic techniques to determine beam direction of 200-MeV H atoms are analyzed. These methods are based on excited hydrogen atoms in n=2 and n=3 levels due to photodetachment of H- ions. An e-beam driven ArF laser can produce H* (2s) atoms for LRF by photoneutralizing H- ions in a quantity comparable to that of a gas cell if longer pulse hot cathode e-beam drivers are developed. Observation of fluorescence from spontaneous decay of H*(2p) or induced decay of H*(2s) can be readily used to indicate beam orientation with 40 - microrad accuracy. Measurements of minute Doppler shifts of this Lyman-alpha radiation by a spectrograph could in principle resolve beam direction to within 2.8 microrad. For schemes requiring n=3 hydrogen atoms, an Xe laser can produce H*(3s) or H*(3p) atoms in quantities larger than any produced previously.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1987
- Accession Number
- ADA189976
Entities
People
- A. Herschcovitch
Organizations
- Brookhaven National Laboratory