Device for scanning a target with a beam of charged particles
US4110623A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 15, 1977 |
| Grant date | Aug 29, 1978 |
| Priority date | — |
| Expiry date | Feb 15, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/1475
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for furnishing a scanning beam intended for irradiating a target, the irradiating dose level having a predetermined distribution on the target. The device comprises a main magnetic system having a plurality of polepieces for scanning the charged particle beam and a secondary magnetic system having a plurality of polepieces and being located upstream of the main magnetic system for variably offsetting the beam entering the main magnetic system. In a preferred embodiment the main and secondary magnetic systems are provided with quadripoles with respective coils which are supplied in pairs with signals S.sub.X1, S.sub.Y1, and S.sub.X2, S.sub.Y2, the signals S.sub.X1, S.sub.Y1 being for example of "sawtooth" waveform and those S.sub.X2, S.sub.Y2 of "squarewave" waveform. The signals may be co-phasal or in phase-opposition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.