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 |
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