Re: [BLAST_SHIFTS] Ion Polarimeter

From: Dan Cheever (cheever@mit.edu)
Date: Mon Jun 02 2003 - 16:14:44 EDT


>
>On Mon, 2 Jun 2003, Adam DeGrush wrote:
>
> > Hi,
> >
> > If by BLAST HV supplies you mean Lecroy HV mainframes, I do believe I
> need to be
> > involved in this as well. Incorporating new elements in the epics
> control is not
> > exactly straightforward.

Hi Guys,
What we need for tomorrow afternoon, tues 6/3, is (1) HV channel under
epics readback and control BUT housed in the existing mainframes used by
BLAST. NOT a new mainframe. Is this a "new element"?....if so please get
started on modifying the database(s) so we can talk to a spare 3mA HV card
under epics. Karens choice of slot.
Call the records "IP:temp:vdac...... idac.. :iadc... :vadc...
Thanks,
-Dan

> >
> > Cheers,
> > Adam
> >
> > Townsend Zwart wrote:
> >
> > > 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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