Performance of the upgraded laser system for the Fermilab-NIU photoinjector

✍ Scribed by Jianliang Li; Rodion Tikhoplav; Adrian C. Melissinos

• Book ID: 103855595
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 565 KB
• Volume: 564
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2006.04.032

✦ Synopsis

The laser system for the Fermilab-NIU photoinjector has been recently upgraded in order to improve reliability and to reduce amplitude fluctuations. Major modifications included the replacement of the oscillator by a diode-pumped passively mode locked Nd:YLF commercial laser. The oscillator delivers 5 ps long pulses at 81.25 MHz at an average power of 450 mW. The number of round trips in the multi-pass amplifier was reduced by half and image relaying was introduced throughout the optical system. The frequency of the IR (l ¼ 1054 nm) pulse was quadrupled to UV (l ¼ 263.5 nm) by two BBO crystals. The overall efficiency for frequency quadrupling was of order 20%. The shot to shot fluctuations in the UV are $5%. The UV energy on the cathode is 5 mJ/pulse (10 mJ/pulse without the pulse stacker), yielding charge of 10 nC/pulse.