Re: [BLAST_SHIFTS] Ion Polarimeter

From: Townsend Zwart (zwart@ROCKO.mit.edu)
Date: Tue Jun 03 2003 - 13:14:21 EDT


Everyone,
        FTP script sounds fine, whatever's easiest for the test. Obviously
these devices should not be turned on with electrodes attached w/o
checking with Ernie.

                                                TZ

Douglas Hasell wrote:
>
> Sorry, I have been distracted recently but I believe it should be possible
> to test the ion polarimeter in the BLAST LeCroy main frames without
> modifying the HV GUI or stealing channels from another detector.
> Eventually using the HV GUI, if appropriate, wil be the right thing to do
> but for the short term we can use FTP as we did for WCHV and BQMHV.
>
> I think Adam or I could easily create an FTP script similar to
> BQMHV that would have the right functionality. Occasionally it will
> interfere with the HVGUI maybe but I was able to monitor wire chamber HV
> while the HV GUI was running and it didn't crash things.
>
> Let me know if you want me to create the script. Just tell me how
> many channels are needed, what they are called or referred to as, and which
> slots and crate they are in.
>
> --On Tuesday, June 3, 2003 11:18 AM -0400 Adam DeGrush <degrush@MIT.EDU>
> wrote:
>
> >
> > Hi,
> >
> > Talking to Townsend it was decided to first test one high voltage for an
> > Ion polarimeter using the hv mainframe to see if it will work. He also
> > suggested using an already allocated channel to do this and it was agreed
> > to use the neutron detector. I will pick one randomly unless somebody
> > directs me otherwise.
> >
> > 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,
> >
>
> Cheers,
> Douglas
>
> 26-415 M.I.T. Tel: +1 617 258 7199
> 77 Massachusetts Avenue Fax: +1 617 258 5440
> Cambridge, MA 02139, USA E-mail: hasell@mit.edu




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