Initial setup for RHIC snakes
Each of the snakes has two power supplies:
For polarized protons we need to have the snakes on at injection.
The snakes run dc, that is, the currents remain constant from
injection up to top energy.
- the "outer" supply for the 1st and 4th helices, and
- the "inner" supply for the 2nd and 3rd helices.
Correct settings for snakes bi9-snk7, yi3-snk7, and bo9-snk7
The correct current for the inner (2.3) supplies is
Iinner = 326.3 A,
and for the outer (1.4) supplies is
Iouter = 100.0 A.
Correct settings for snake yo9-snk7 with only one supply
The correct current for the outer (1.4) supply is
Iouter = 300 A. (Web page value corrected: 27 May, 2003)
On of the inner helices is broken, so the inner supply should not
Turning on the snakes.
using the TAPE program as given by Don Bruno
Rough outline of steps for the 1st time before establishing capture
- Establish circulating beam at injection in RHIC.
- We need a good orbit in the vicinity of the snakes. The orbit
should be adjusted by averaging 100 turns or so at injection.
- Each snake should be ramped up in steps and the vertical corrector
nearest the snake should be adjusted to remove any distortions
caused by the snake.
Waldo recommends going up to 100 A
for both power supplies in the first step, then ramping the inner
power supply and correcting with steps to 200, 275, 300, 326.3.
- Note the last 50A for the inner supply
cause the most distortion.
- Note: We must NOT exceed the ramp rates given in Don Bruno's
Turning the snakes back on after we have a good solution
The snakes should be on before trying to inject the beam.
Bring them on according to Don's
Pay attention to Don's ramp rates. (We will soon be able to turn them
on via Johannes' snake application from last year once he verifies the
There is a pet page which may be used for controlling all the RHIC snakes
GPM plots for snakes
- for monitoring snake bpms:
- for monitoring rotator bpms:
- for monitoring snake power supplies:
- for monitoring rotator power supplies: