Double-decker femtosecond electron beam accelerator for pulse radiolysis

• Published in: Review of scientific instruments 2006-04, Vol.77 (4), p.043302-043302-5
• Main Authors: Yang, Jinfeng, Kondoh, Takafumi, Yoshida, Akira, Yoshida, Youichi
• Format: Article
• Language: English
• Subjects: BEAM BUNCHING; ELECTRON BEAMS; LASERS; LINEAR ACCELERATORS; MAGNETIC FIELDS; MEV RANGE 10-100; PARTICLE ACCELERATORS; PHOTOCATHODES; PULSES; RADIATION CHEMISTRY; RADIOLYSIS; RADIOWAVE RADIATION; RF SYSTEMS
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.2195090

A new concept of double-decker electron beam accelerator based on a photocathode radio-frequency (rf) gun was proposed for studying chemical kinetics and primary processes or reactions of radiation chemistry. The synchronized double-decker electron beams with time interval of 1.4 ns were generated in the rf gun by injecting two laser beams on the photocathode. The double-decker electron beams were accelerated by a booster linear accelerator (linac) up to 31.8 MeV with energy-phase correlation and compressed into femtosecond by rotating the bunch in the energy-phase distribution in magnetic fields. The normalized transverse emittance of both beams downstream of the linac was obtained to be 2.5 ± 0.6 mm mrad for the up beam with bunch charge of 0.47 nC and 3.6 ± 0.7 mm mrad for the down beam with bunch charge of 0.65 nC . The minimum relative energy spread was ( 0.14 ± 0.03 ) % for the two beams. The compressed bunch length was obtained to be 430 ± 25 fs for the up bunch and 510 ± 20 fs for the down bunch.