hi, to echo Genya and Nick's messages:
using Aki's code, the average unpol target flow for the 1torr and
3torr runs are:
1 torr: 4.34 +/- 0.27 * 10^15 mol/sec
3 torr: 12.38 +/- 0.26 * 10^15 mol/sec
divide the Genya's rates by the flows:
1 torr: 0.098 +/- 0.002 /C/(mol/sec)
3 torr: 0.094 +/- 0.003 /C/(mol/sec)
a slight 1 sigma difference. dR = 0.004 +-/ 0.004
on my book, with tighter cuts for ed-elastic:
1 torr: 0.061 +/- 0.002 /C/(mol/sec)
3 torr: 0.061 +/- 0.002 /C/(mol/sec)
no difference at all, the fit would be perfectly linear going through the
origin.
the systematic difference in the two buffer flow measurement should be
small because the two series of runs are adjacent. and should even
cancel out when one only compares the ratio of the two rates. compare to a
set of 2 torr runs taken two weeks before these runs, the value of
events/C/(mol/sec) is different from 0.061 by a much larger margin.
Chi
On Mon, 13 Jun 2005, Genya wrote:
>
> Dear all,
> First, I have to say that my claim about huge drop of the rate at
> the unpol run with increased
> target density was wrong. As it turned out, I used wrong run numbers.
> Now I'd like to present a clarified picture. eD elastic events are
> used for retes.
> 1. Target density dependence in unpol runs.
> a) normal density (Pbuf=2 torr) R=793+-6 events/kC
> b) Pbuf = 1 torr R=424+-6
> (expected - 397)
> c) Pbuf = 3 torr R=1160+-12
> (expected -1190)
> One may note, that with reduced target thickness, rate is a bit
> higher than expected, and at
> high density rates are smaller than expected. Not by much, but ourside
> error bars. I believe,
> Nick observed similar picture in inclusives.
> 2) Current dependence in ABS runs, the target is at the same state
> (age?) for both runs.
> a) normal conditions (Imax~230 mA) R=674+-7
> b) Imax=100mA R=904+-9
> Here the effect is much more dramatic. At low current rates a MUCH
> higher.
> The only reasonable explanation I can come up witth is that wire
> chamberrs efficiency (or, rather,
> efficiency of reconstruction) depends on the wire chambers rate, and
> that during our "normal" conditions
> this efficiency is less than 75%. With low current, the chambers rate
> drops very drastically, and changes
> in target thickness have much smaller effect.
> Genya
>
>
>
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