The first “Twin Orbit User Test week” at BESSY II in February 2018 was a big success and can be considered as an important step towards real user operation.
Physicists at Helmholtz-Zentrum Berlin have been able to store two separate electron beams in one storage ring. The twin orbit operation mode can serve users with different needs of the time structure of the photon pulses simultaneously and offers elegant options regarding the future project BESSY VSR.
The Twin Orbit operation mode makes use of non-linear beam dynamics and provides two stable well separated orbits for storing two electron beams in one storage ring. The bunch fill patterns of both orbits can be chosen, to some extent, independently, which allows for fulfilling normally incompatible user needs, simultaneously. For example, one orbit can be used to store a homogenous multi bunch fill to deliver high average brilliance for photon hungry experiments, whereas only one single bunch is stored on the other orbit for timing experiments, providing a much lower pulse repetition rate.
>Read more on the Bessy II at HZB website
Image: A synchrotron source point image of a bending magnet of the Twin Orbit modus. The second orbit closes after three revolution and is winding around the standard orbit at the center. (full image here)
Credit: HZB