Upgraded laser wire beam profile monitor

Yosuke Honda, Noboru Sasao, Sakae Araki, Yasuo Higashi, Toshiyuki Okugi, Takashi Taniguchi, Junji Urakawa, Yoshio Yamazaki, Koichiro Hirano, Masahiro Nomura, Mikio Takano, Hiroshi Sakai

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


We describe in this report an upgraded version of the laser wire beam profile monitor developed at KEK to measure a low-emittance electron beam in the ATF damping ring. This monitor is based on the Compton scattering of electrons with a laser light target. A thin and intense laser beam is produced by exciting a Fabry-Perot optical cavity with a CW laser. Various improvements were made to the original setup. First, the effective laser power inside the cavity was increased by an order of magnitude, leading to a drastic increase in a signal-to-background ratio and a decrease in measurement time. Second, readout circuits were modified to separately measure beam sizes of each bunch in a multi-bunch beam. Third, two cavities were installed to measure both horizontal and vertical beam sizes. With this upgraded setup, measurements of electron beam emittance operated in a multi-bunch mode were carried out successfully.

Original languageEnglish
Pages (from-to)100-115
Number of pages16
JournalNuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Issue number1-3
Publication statusPublished - Feb 11 2005
Externally publishedYes


  • Beam emittance
  • Compton scattering
  • Fabry-Perot cavity
  • Laser wire

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation


Dive into the research topics of 'Upgraded laser wire beam profile monitor'. Together they form a unique fingerprint.

Cite this