Beamline 1W1 of Beijing Synchrotron Radiation Facility (BSRF) started to operate in the parasitic mode of BEPCII at 4am of April 6. Thanks to the hard work of beam controlled team, it became the second beamline with wiggler that could run while BEPCII was working for high energy physics experiments.

BEPCII has two running modes. One is mainly for high energy physics experiments called the parasitic mode, in which some beamlines could also operate for synchrotron radiation (SR) experiments; the other is only for SR experiments called the dedicated mode. Since 2010, 5 beamlines of BSRF (4 bending magnets and 1 Wiggler) started to open to users in the parasitic mode. 1W1A and 1W1B came from Wiggler 1W1 are two experimental stations with great SR experiments demand. However, the operation of 1W1 (between two Injection kicker magnets) will be affected by the circulating beam when the electron beam injected. Meanwhile, 1W1 has a great influence on the collider brightness. So the commissioning of 1W1 in the parasitic mode was postponed for a long time. In the operation of 2013~2014, according to the off-line analysis and simulation of 1W1 by accelerator physicist, beam controlled team finished the debugging of 1W1 and minimized its effect to the collider brightness of BEPCII.

Finally, 1W1A-Diffuse X-ray Scattering and 1W1B-X-ray Absorption Fine Structure opened to users for synchrotron radiation experiments in the parasitic mode for the first time on April 14.