Characteristics of Beam Modes at the ESRF

Beam mode & characteristics
Intensity
Lifetime
Beam
Uniform filling mode
992 bunches are equally distributed around the whole circumference of the storage ring.
Refill time: ~3 minutes

200 mA

60 hours

Low emittance
(4 nm) with 1% coupling
2*1/3 filling mode
2 times one third of the storage ring is filled. The 2 one thirds are separated by an empty gap of 1/6th of the ring.
Top up time: ~3 minutes
200 mA
55 hours
Low emittance
(4 nm) with 1 % coupling.
7/8 + 1 filling mode

A train of 868 bunches (7/8 of the Storage Ring circumference) filled with 200 mA (0.23 mA / bunch).
Both edges of the train are filled with 1 mA single bunch

The remaining 1/8 gap is filled in its center with a cleaned 2 mA-single bunch
Filling time:
~ 5 minutes
200 mA
55 hours
Low emittance
(4 nm) with 1% coupling.
Hybrid mode 24*8 + 1 filling mode
One clean 4mA single bunch diametrically opposed to a ~ 196 mA multi-bunch beam composed of 24 groups of bunches spread over 3/4 of the storage ring circumference.
Filling time: ~ 10 minutes.
200 mA
25 hours (single bunch) 40 hours (24*8 bunches) -> resulting lifetime ~ 40 hours Low emittance
(4 nm) with 1 % coupling.
16 bunch filling mode
16 highly populated and equally spaced bunches. Purity < 10-7
Filling time: ~5 mins.
90 mA
10 hours
Low emittance
(4 nm) with 2% coupling
4*10 filling mode
4 equidistant bunches _ 10 mA/bunch
Filling time: ~ 5 minutes
40 mA 6 hours Low emittance
(4 nm) with 2% coupling.
MDT (Machine Dedicated time)
Operation for machine physics
Depending on programme
Depending on programme
Depending on programme
Shutdown
Shutdown period of the machine for maintenance, repairs, installation etc.
No beam
No beam
No beam