An Automatic Magnetic Bubble Mobility Measurement System Employing Video Processing.
Abstract
A semi-automatic bubble mobility measurement system employing a Zeiss Ultraplot 3B microscope, video camera, and processing circuitry was designed and constructed. The method of measurement was static in nature i.e. measurement of the pre and post-drive domain positions. A two piece mobility stage was constructed. The stage base incorporated a removable bias field coil capable of generating a 160 gauss field with little heat generation. The brass specimen holder contains the drive field coil. An E and H 123 pulse generator/amplifier provides the 50 volt, one microsecond drive field current pulse. The electronics section converts the domain's light contrast difference in the microscope to a voltage difference in time. Voltage contrast differences of 0.7 volts and domain widths of 2us are required to achieve discrimination. A HP 9825 compatible mobility computation program was written and debugged. This program calculates the domain mobility based on displacement measured by the electronics section. Simulated domain contrast differences were used to validate the system. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1978
- Accession Number
- ADA055636
Entities
People
- Richard Leo Eilers
Organizations
- Air Force Institute of Technology