| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic field lens capable of generating a substantially constant amount of average thermoelectromotive force over a pre-selected range of magnetic field strength. SOLUTION: The lens includes asymmetric multi-coil parts (with the different number of turns), produces a desired range of field strength, and at the same time, maintains a sufficiently constant temperature signal when the total average electromotive force is maintained constant whereby, excessive delay in lens operation is avoided when the magnetic field strength is changed. The coil with the fewer number of windings in the asymmetric lens structure has relatively less inductance, thereby making it more responsive and amenable quickly for an AC drive signal and thus dynamic focusing applications if desired. COPYRIGHT: (C)2011,JPO&INPIT |
