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Hi Richard,<br>
<br>
From my point-of-view, having hdgeant4 supporting only mode 3 is
fine. This is essentially the decision we made with the recent
updates to hdgeant3. In principle mode 2 provides a more detailed
microscopic description of the generation of BCAL pulses, but we
found that our implementation was incomplete and would require
substantial effort to make it match existing data. <br>
<br>
We do want to make sure that we understand what is being included in
the MC, so it would be good for you to give us an update at one of
our BCAL reconstruction meetings.<br>
<br>
Thanks, Elton.<br>
<pre class="moz-signature" cols="72">Elton Smith
Jefferson Lab MS 12H3
12000 Jefferson Ave STE 4
Newport News, VA 23606
(757) 269-7625
(757) 269-6331 fax </pre>
<div class="moz-cite-prefix">On 8/28/15 3:35 PM, Richard Jones
wrote:<br>
</div>
<blockquote
cite="mid:CABfxa3TMYBZe4-XDq=M0kJ6aXAap2oeRezB1PKZiuF9JgGr6hg@mail.gmail.com"
type="cite">
<div dir="ltr">Hello Tegan,
<div><br>
</div>
<div>I am setting up to implement the readout of BCal hits in
hdgeant4, and I have a question about which mode of output you
want me to support. The hddm output record defines several
different styles for recording event output:</div>
<div>
<ol>
<li>bcalSiPMupHit/bcalSiPMdownHit - these are marked
"obsolete" in the template</li>
<li>bcalSiPMSpectrum - introduced to try and understand the
role of noise in the fADC stream</li>
<li>bcalADChit / bcalTDChit (and their "digi" counterparts)
- probably the closest to what the DAQ actually produces.</li>
</ol>
<div>If I had my druthers, I would only support output from
hdgeant4 in mode 3, and not modes 1 or 2. If I were to do
that, would there be significant information lost that you
would like to recover? Would you like to have both modes 2
and 3 available, selectable by an option in <a
moz-do-not-send="true" href="http://control.in">control.in</a>
or something like that? Or is mode 2 pretty much obsolete as
well?</div>
</div>
<div><br>
</div>
<div>Anyone else in the calorimeter working group that has an
opinion on this should feel free to respond to my question as
well, but I understand from Justin that Tegan is probably the
man to ask.</div>
<div><br>
</div>
<div>-Richard Jones</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Thu, Apr 30, 2015 at 4:47 PM, Elton
Smith <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:elton@jlab.org" target="_blank">elton@jlab.org</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> Hi Tegan,<br>
<br>
Sorry we missed the meeting this morning. I will try to
provide answers/comments where I can. Others can also
provide feedback.<br>
<br>
= New code = <br>
* Poisson statistics smearing still needs a value for the
energy of one dark hit.<br>
<br>
Attached is a script and plots of a single pixel firing,
with the normalization of summed energy of 0.31 MeV/pixel.
Note, however that his depends on several factors. This is
an average value for energy deposited in the middle of a
module. Of course the actual amount of energy deposited
with that amplitude will depend on the position of the
energy deposition. Also, I have used a gain factor of
0.046 MeV/integral count. But these vary quite a bit from
cell to cell. See Will's log entry detailing the gain
factors obtained for the fall run:<br>
<a moz-do-not-send="true"
href="https://logbooks.jlab.org/files/2015/03/3328508/BCAL_Calib_Update_Mar20.pdf"
target="_blank">https://logbooks.jlab.org/files/2015/03/3328508/BCAL_Calib_Update_Mar20.pdf</a>.<br>
However, the question itself regarding what energy
corresponds to a single pixel is a little misleading. If
one is simulating dark hits (i.e. single pixels), these do
not correspond to energy per se but rather an amount of
charge into the FADC. This is better characterized by the
number of FADC counts that correspond to one pixel firing
(see figure). This is independent of attenuation length.
It is does depend on the gain of the sensor and
electronics. However, there are many contributions to the
"gain" or conversion from counts to MeV. For example, the
acceptance/transmission of the light guides contributes to
the overall gain factor and this has nothing to do with
the size of the single pixel. Therefore, it might make
more physical sense to simulate the dark hits with minimal
dependence on each channel. If we operate the SiPMs at the
same over bias, this should correspond to the same gain
for all sensors. Therefore, the large variation we are
seeing in "gains" may not be primarily due to the actual
sensor gains themselves.<br>
<br>
Hope this gives you sufficient information to think about
how to move forward.<br>
<br>
* What should we use for an energy threshold to write out
events? A 4 mV threshold was used before. 4 MeV?<br>
<br>
The threshold should be given in counts, which corresponds
to the DAQ threshold of 105. The pedestal is nominally at
100, so 5 counts above pedestal. We are using the 2 V
scale on the FADCS, which are 12 bits, so one count =
0.0004884 V. Therefore 5 counts is 2.44 mV assuming the
pedestal does not drift. Of course it does, so another
question is whether we wish to include pedestal drifts in
the simulation. Generally one tries to setup hardware, so
the software can ignore such details, but this may not be
possible in this case.<br>
<br>
In any case, the thing to do is to convert the energy
deposited into counts, use the pulse shape I have provided
(or your own favorite) to convert this into fADC counts.
The threshold would be applied to this pulse train.<br>
<br>
<br>
* The change to the data structure will be just adding
'incident_id="int"' to 'bcalTruthHit.'<br>
<br>
Others with more expertise should comment on this one.<br>
<br>
** If we don't change the data structure, we'll change
bcal_index in the code and get rid of the incident
particle filling.<br>
** I'd prefer changing the data structure, since we'll
eventually want to implement incident particle dependent
smearing (I assume), and it seems relatively easy to do it
now.<br>
<br>
* Time smearing: the time resolution in the code for the
fADC is stated as 4 ns / sqrt(12). This was used before
because we were using 0.1 ns bins rather than 4 ns bins.<br>
<br>
This is probably an old guess based on assuming the time
coming from the fADC comes from picking the first FADC
sample above some some threshold. We are doing much better
than this by essentially finding the time at half height.
The resolution for this is about 0.2 - 0.3 ns, but Mark
can probably provide a better number. I suggest you put in
a value based on Marks latest studies and we can adjust it
as more studies are done.<br>
<br>
** Is this value what we'd want to use for smearing a
single truth time?<br>
<br>
<br>
= Old code =<br>
* We need to decide whether or not we want to keep this
method available for people to choose to use.<br>
* If we do keep it:<br>
** Need to find a value for the energy of one dark hit
that causes waveforms to more closely resemble data and
also that gives reasonable pedestal variation.<br>
<br>
Using the attached scritps used for the pedestal studies,
I think we a first stab at this. See GlueX-doc-2695<br>
<a moz-do-not-send="true"
href="http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2695"
target="_blank">http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=2695</a><br>
You can find all the scripts in the tar.gz file. If there
is anything missing, let me know and I can make it
available.<br>
<br>
** By fixing an electronic noise smearing, then altering
the dark hit energy, it looks like we want something like
the current energy divided by 10 or so.<br>
** It should be easy to set the dark hit energy based on
what amplitude in mV we want the dark pulses to have, if
we have any feeling for that (1 mV amplitude ~ 1 MeV
energy deposition).<br>
<br>
See the notes and GlueX notes above, which should provide
good answers to these questions.<br>
<br>
<br>
<pre cols="72">Elton Smith
Jefferson Lab MS 12H3
12000 Jefferson Ave STE 4
Newport News, VA 23606
<a moz-do-not-send="true" href="tel:%28757%29%20269-7625" value="+17572697625" target="_blank">(757) 269-7625</a>
<a moz-do-not-send="true" href="tel:%28757%29%20269-6331" value="+17572696331" target="_blank">(757) 269-6331</a> fax </pre>
<div>
<div class="h5">
<div>On 4/30/15 1:12 PM, Zisis Papandreou wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div class="h5"> Hi folks:
<div><br>
</div>
<div>the minutes from our short meeting this morning
have been posted:</div>
<div><a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/BCAL_Reconstruction_Meeting_2015-04-30"
target="_blank">https://halldweb.jlab.org/wiki/index.php/BCAL_Reconstruction_Meeting_2015-04-30</a></div>
<div><br>
</div>
<div>Please note that since there was a controlled
access in the hall at the same time as the
meeting, JLab was not able to join us. Therefore,
we posted Tegan's questions on HDGEANT and mcsmear
on the Wiki (see above minutes). I've placed this
discussion at the top of the agenda of next week's
Calorimetry meeting, as it is important to
progress on this and complete the tasks. Will L.
will also join us for next week's meeting.</div>
<div><br>
</div>
<div>We are hoping that after the commissioning ends
on Monday, folks will have a chance to read this
list so that we can decide upon the items and move
forward.</div>
<div><br>
</div>
<div>I also posted the minutes from the April 16
meeting: <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/BCAL_Reconstruction_Meeting_2015-04-16"
target="_blank">https://halldweb.jlab.org/wiki/index.php/BCAL_Reconstruction_Meeting_2015-04-16</a></div>
<div><br>
</div>
<div>Thanks and cheers, Zisis...<br>
<div>
<div
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<div style="word-wrap:break-word"><span
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<div
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style="border-collapse:separate;font-variant:normal;letter-spacing:normal;line-height:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;border-spacing:0px">
<div
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style="border-collapse:separate;font-variant:normal;letter-spacing:normal;line-height:normal;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;border-spacing:0px">
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<div
style="word-wrap:break-word">
<div><font
face="Verdana"
color="#1d5091" size="4"><br>
Dr. Zisis
Papandreou</font></div>
<div
style="color:rgb(0,0,0)"><span
style="font-size:13px"><font face="Verdana">Professor of Physics, Ph.D.,
P.Phys.</font></span></div>
<div
style="color:rgb(0,0,0)"><span
style="font-size:13px"><font face="Verdana">---------------------------------------------------------</font></span></div>
<div
style="font-size:12px;font-style:normal;font-weight:normal"><font
face="Verdana"
color="#929292">Department of Physics </font></div>
<div
style="font-size:12px;font-style:normal;font-weight:normal"><font
face="Verdana"
color="#929292">University of Regina<span style="white-space:pre-wrap">
</span> </font></div>
<div
style="font-size:12px;font-style:normal;font-weight:normal"><font
face="Verdana"
color="#929292">3737 Wascana Parkway</font></div>
<div
style="font-size:12px;font-style:normal;font-weight:normal"><font
face="Verdana"
color="#929292">Regina, SK S4S 0A2<span style="white-space:pre-wrap">
</span> CANADA</font></div>
<div
style="color:rgb(0,0,0);font-size:12px;font-style:normal;font-weight:normal"><font
face="Verdana"><br>
</font></div>
<div
style="color:rgb(0,0,0)"><font
face="Verdana"><b>Phone:
<a
moz-do-not-send="true"
href="tel:%28306%29%20585-5379" value="+13065855379" target="_blank">(306)
585-5379</a></b></font></div>
</div>
</span></div>
</span></div>
</span></div>
</span></div>
</span></div>
</span><span
style="font-family:Verdana;font-size:12px"><font
color="#929292">Fax: (306) 585-5659</font></span>
<div><span
style="font-family:Verdana;font-size:12px"><font
color="#929292">Email:</font> </span><a
moz-do-not-send="true"
href="mailto:zisis@uregina.ca"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:zisis@uregina.ca">zisis@uregina.ca</a></a></div>
<div>
<div style="word-wrap:break-word"><font
face="Verdana" color="#929292">Website:</font> <a
moz-do-not-send="true"
href="http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html"
style="text-align:-webkit-auto"
target="_blank"><a class="moz-txt-link-freetext" href="http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html">http://www.uregina.ca/science/physics/people/faculty-research/zisis-papandreou/index.html</a></a></div>
</div>
</span><br>
</div>
<br>
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<br>
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