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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Subject:
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<td>Re: BCM accuracy</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">Date: </th>
<td>Mon, 6 May 2013 17:22:17 +0800</td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">From: </th>
<td>Pengjia <a class="moz-txt-link-rfc2396E" href="mailto:pzhu@jlab.org"><pzhu@jlab.org></a></td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">To: </th>
<td>Jian-ping Chen <a class="moz-txt-link-rfc2396E" href="mailto:jpchen@jlab.org"><jpchen@jlab.org></a></td>
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<th nowrap="nowrap" valign="BASELINE" align="RIGHT">CC: </th>
<td>Alexandre Camsonne <a class="moz-txt-link-rfc2396E" href="mailto:camsonne@jlab.org"><camsonne@jlab.org></a></td>
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<div>Hi JP,<br>
Sorry for late, I don't know the deadline is tonight before.<br>
I checked several production runs by using T3 count and bcm
count saved in helicity ringbuffer(since there is more events
saved in ringbuffer raw data(1 event recorded per 0.001s) than
in normal sis3800 scaler(1 event recorded per 2s), also I
checked from normal sis3800 scaler and got same result), the
main idea is:<br>
1.calculate the charge(after calibration) rise,T3 count rise
per 1 second(bcm count rise in 1 sec), time use fastclock<br>
2.get the ratio between T3 count rise and charge rise(total),
fit it as charge=a+b*t3<br>
3.get the relationship between
(charge_per_sec-(a*t3_per_sec))/charge_per_sec<br>
The result is:<br>
by using run from 4234 to 4249, from 4/12/2012 14:24 to
4/12/2012 18:50, <br>
the result can be shown in attachment, t3ps is t3 count per
second, upps is calibrated upstream bcm charge per second, clk
is from fastclock/103920, unit is second<br>
the stability in 5 hours can be reach as 0.75%, less than 1%,
</div>
more data need to be replayed for study for more than 20hours.<br>
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<div class="gmail_extra"><br clear="all">
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<div>Pengjia</div>
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<br>
<div class="gmail_quote">On Mon, May 6, 2013 at 4:51 AM,
Jian-ping Chen <<a moz-do-not-send="true"
href="mailto:jpchen@jlab.org">jpchen@jlab.org</a>>
wrote:<br>
<blockquote class="gmail_quote">
<div bgcolor="#FFFFFF" text="#000000"> Pengjia,<br>
<br>
The deadline for submitting the proposal is 8 am Monday
(US East time),<br>
Will need the inf on long-term (~20-24 hours) stability
for the BCM some hours<br>
before the deadline. We have only a few hours left.let
me know if you have anything.<br>
<br>
Thanks.<br>
<br>
Jian-ping
<div>
<div class="h5"><br>
<br>
<div>On 5/4/2013 5:16 AM, Pengjia wrote:<br>
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<blockquote type="cite">
<div dir="ltr">
<div>Hi JP, Alex,<br>
</div>
I will figure it out as soon as possible,
Thanks!<br>
</div>
<div class="gmail_extra"><br clear="all">
<div>
<div>Pengjia</div>
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<br>
<br>
<div class="gmail_quote">On Sat, May 4, 2013 at
5:56 AM, J. P. Chen <<a
moz-do-not-send="true"
href="mailto:jpchen@jlab.org">jpchen@jlab.org</a>>
wrote:<br>
<blockquote class="gmail_quote">
<div text="#000000" bgcolor="#FFFFFF"> Hi,
Pengjia and Alexandre,<br>
<br>
I need information on BCM for 100 nA.
Precision and stability.<br>
Also a question: do we reach 1%
(statistics) in less than 1 s?<br>
<br>
Thanks.<br>
<br>
Jian-ping
<div>
<div><br>
<br>
<div>On 5/3/2013 5:36 PM, Alexandre
Camsonne wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div>I guess you could normalize
by trigger rates too to correct
for beam fluctuations.<br>
<br>
</div>
Alexandre<br>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Fri,
May 3, 2013 at 5:19 PM,
Alexandre Camsonne <<a
moz-do-not-send="true"
href="mailto:camsonne@jlab.org">camsonne@jlab.org</a>>
wrote:<br>
<blockquote class="gmail_quote">
<div dir="ltr">
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<div>Hi
Pengjia,<br>
<br>
</div>
JP would need
the accury to
which we
measure the
charged=<br>
at 50 nA.<br>
<br>
</div>
I need to look
back at the
data<br>
<br>
</div>
but I think we
have several
calibrations<br>
</div>
with the
calorimeter.<br>
<br>
</div>
Could you make a
plot of the
stability<br>
</div>
of the calibration
constants ?<br>
<br>
</div>
Also can you plot the
width of the measured
current ?<br>
<br>
</div>
And give the resolution
on the current we have :<br>
<br>
</div>
sigma / mean.<font
color="#888888"><br>
<br>
<br>
</font></div>
<font color="#888888">Alexandre<br>
</font></div>
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