Hi Ricardo,
Yes, I agree very much that we should implement the inclusive trigger.
Incidentally, Jo has sent email theta he will come the week of September
19th.
Richard
On Mon, 1 Sep 2003, Ricardo Alarcon wrote:
> Hi Richard,
>
> If not already done I would like to propose that we implement an inclusive
> trigger that uses the Cerenkov detectors. We should do this in the present
> running with hydrogen. This should be a simple matter and the only issue is
> event rate which can be dealt through pre-scaling.
>
> I have two students who can start right away evaluating the quality of the
> data and performing preliminary analysis.
>
> With this trigger we can get another measurement of the elatic scattering
> asymmetry and get very good statistics in the Delta region. Radiative
> corrections are going to be very important so the sooner we start the
> better.
>
> Thanks,
>
> Ricardo
>
>
>
> -----Original Message-----
> From: richard milner [mailto:milner@mitlns.mit.edu]
> Sent: Sun 8/31/2003 5:50 PM
> To: Electronic Log Book
> Cc: Blast_shifts@rocko.mit.edu
> Subject: Re: [BLAST_SHIFTS] Shift summary 08/31/2003 E (16-20)
>
>
>
> This is interesting. We should continue to take data with decreasing
> atomic fraction (AF) for a couple of days. We should look for a
> correlation of the measured asymmetry with the measured AF. Each day we
> should also measure the AF and its dependence on the MFT being ON or OFF.
> Does this track with lower sextupole pressure? How muc ep data do we have
> to take to see a 10-15% chnage in the target polarization?
> Richard
>
> On Sun, 31 Aug 2003, Electronic Log Book wrote:
>
> > Operators: ajmasch vziskin tavi
> >
> > Running beam untill 18:30. Stopped to measure the atomic fraction.
> > The atomic fraction in the cell with MFT 2-3 off was measure 43 to 45
> (current dependance)%. I found a MFT 2-3 resonace @ -5 Amp with the BLAST
> field off. With this MFT2-3 on the mass1 signal drops by about a half
> (current correction needed) however mass2 dropped by significantly less(less
> than 1/3). The atomic fraction with MFT2-3 is 39.3 % which is more
> consistant with the data (on that later). This indicates that there is a
> significant number of H2 that does not come from the recombination
> (otherwise H2 would also drop by a half).
>
> >
> > The data definately shows an assssymetry, with dilution factor of about
> 0.18 (60 and 30% beam and target respectively), with the asymmetry from
> latter data showing slightly lower dilution. However, the bigger issue is
> the left/right inconsistancy. Electron on the left asymmetry look very
> dissent. Electron on the right looks a lot worse. I looked into the issue
> further and found that my making even tighter cuts on the vertex this
> discrepancy seems to reduce. Upon further investigation I found the
> negative overall electron-right asymmetry gets diluted by mostly "positive
> asymmetry" comming from downstream (????). More statistics need for
> investigation. By comparison, electron-left asymmetry vs. vertex looks
> exactly like you would expect it.
>
> >
> >
> >
> >
>
>
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