Controller for a linear accelerator
US6462489B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2001 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Sep 10, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31701
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for generating an accurate, stable phase shift (b) in a sinusoidal signal employs fast analog multiplication to implement the trigonometric relationship sin(&ohgr;t+b)=sin(&ohgr;t)cos(b)+cos(&ohgr;t) sin(b). Cos(&ohgr;t) is generated by accurately shifting a signal sin(&ohgr;t) through 90° C. using a delay line, for example. Sin(b) and cos(b) are dc signals generated by digital to analog conversion, using a demanded phase shift (b) whose sine and cosine are obtained from look-up tables. A controller for controlling a phase shift in an rf cavity is also disclosed and operates on the basis of the same trigonometrical principle. The amplitude of the signals in the rf cavity is also controllable; fast analog multipliers are again employed to scale the signal amplitude to a nominal fixed value such as 1 volt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.