Dear All,
I propose we take the following actions w.r.t ION polarimeter devices.
1) EMCO supplies should be replaced. These devices are inadequate.
Let's try BLAST HV supplies which have current readback. Dan is
coordinating this with Karen and Tancredi. We do not need to move them
all at once.
2) Results of tests show that the sagging voltage on upstream spherical
deflector is e-beam related and independent of supply voltage and target
thickness. We should see how this device performs with a better supply.
Either EG&G or BLAST HV.
3) Failing ION polarimeter should be run at 30 kV for now. There is no
need to run this device at 60 kV until we want scattering asymmetry. We
are constructing a printed circuit board floating ammeter which will
have better HV standoff properties. This should be available in ~two
weeks.
TZ
Yuan Xiao wrote:
>
> For 5/30 C shift:
>
> Around 9:30pm, got the beam to measure the RF effect of the
> storage ring to the lenses. No obvious effect was observed
> -- the signal picked up by the HV cable from lenses was only
> 1dbm bigger than the noise picked up at D tunnel.
>
> Current from each lenses was measured again. Several nA
> was got from the split lenses before and after Wien Filter (WF)
> and from WF plates. Tens of uA was seen from the outer shell
> of the spherical deflector (SD) and the plit lens before it; no
> current was seen from the inner shell of SD.
>
> Chi, Yuan, Genya,
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