<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial"><div>dear all<br></div><div><br></div><div>we have found the reason of my problem. As prof. feng mentioned, the PMT anode current is saturate for vertical test.</div><div>now we are doing the horizontal test. The input signal is smaller than vertical test, so we didn't use attenuator. here are the results:</div><div><br></div><div>pmt1000V(Gain=3.1E6) QDC=500(most probable value) pedstal=90 <br></div><div>Npe=[(500-90)*0.1*1E-12] /[3.1E6*1.6E-19]=(500-90)/(3.1*1.6)=82</div><div><br></div><div>pmt1100V(Gain=6.5E6) QDC=1000(most probable value) pedstal=90 <br></div><div>Npe=[(1000-90)*0.1*1E-12] /[6.5E6*1.6E-19]=(1000-90)/(6.5*1.6)=87</div><div><br></div><div>For horizontal test, <span id="result_box" class="short_text" lang="en"><span class="">NPE does not vary with HV, this is normal. </span></span><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">So we can be sure that the problem is due to the vertical test signal is too large to lead to PMT saturation.</span></span></span></span></div><div>the number of event for two HV points just is 20.<span id="result_box" class="" lang="en"><span class=""> Our test is still continuing to get more events</span></span>.<br></div><div><br><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">Therefore, npe would be 748 if the PMT is not saturated under 1000V in the vertical test. </span></span></span></span></span></span><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">The npe would be greater than 748 if the PMT is saturated under 1000V.</span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">after horizontal test, we will do vertical test again. we will test the NpE under the 900V. If Npe also is 750, we would ensure that </span></span></span></span></span></span></span></span></span></span><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">it is not saturated under 1000V in the vertical test.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><br></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">On the other hand, </span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">Beijing Hamamatsu test staff told me that the results of the two test methods £¨spe & sp/sk£©will not be much different.</span> <span class="">And they think that the SP / Sk method is more accurate.</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><br></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">best regards,</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="short_text" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class=""><span id="result_box" class="" lang="en"><span class="">chendi<br></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></div><div><br></div><div><br></div><div><br></div><br><br><br><div style="position:relative;zoom:1">--<br><div style="font-family: 'lucida Grande', Verdana, 'Microsoft YaHei'; font-size: 12px; line-height: 23.8px;"><i><font style="line-height: 22.1px;" size="2"><font style="line-height: 22.1px;" face="ºÚÌå">Éê³ÀµÏ </font><font style="line-height: 22.1px;" face="Arial"> Chen-di Shen</font></font></i></div><div style="font-family: 'lucida Grande', Verdana, 'Microsoft YaHei'; font-size: 12px; line-height: 23.8px;"><font style="line-height: 22.1px;" size="2" face="Arial"><i>Department of Engineering Physics, Tsinghua University</i></font></div><div style="font-family: 'lucida Grande', Verdana, 'Microsoft YaHei'; font-size: 12px; line-height: 23.8px;"><font style="line-height: 22.1px;" size="2" face="Arial"><i><span style="line-height: 23.8px;">418, Liuqing Building, THU, Haidian District, Beijing, China,</span><span style="line-height: 23.8px;"> </span><span t="7" data="100084" style="line-height: 23.8px; border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(204, 204, 204); z-index: 1;"><span t="7" data="100084" style="border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(204, 204, 204); z-index: 1;">100084</span></span></i></font></div><div style="font-family: 'lucida Grande', Verdana, 'Microsoft YaHei'; font-size: 12px; line-height: 23.8px;"><font style="line-height: 22.1px;" size="2" face="Arial"><i><span style="line-height: 23.8px;">Tel£º86-</span><span t="7" data="15201523510" isout="1" style="line-height: 23.8px; border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(204, 204, 204); z-index: 1; position: static;"><span t="7" data="15600915869" style="border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(204, 204, 204); z-index: 1;">15600915869</span> & <span t="7" data="86-18101259887" isout="1" style="border-bottom-width: 1px; border-bottom-style: dashed; border-bottom-color: rgb(204, 204, 204); z-index: 1; position: static;">86-18101259887</span></span></i></font></div><div style="font-family: 'lucida Grande', Verdana, 'Microsoft YaHei'; font-size: 12px; line-height: 23.8px;"><font style="line-height: 22.1px;" size="2" face="Arial"><i>email: <a href="mailto:shenchendi404@qq.com" target="_blank" style="outline: none; cursor: pointer; color: rgb(99, 72, 25);">shenchendi40<wbr></wbr>4@163.com</a></i></font></div><div style="clear:both"></div></div><div id="divNeteaseMailCard"></div><br>At 2017-09-10 18:05:23, "Cunfeng Feng" <cunfeng.feng@cern.ch> wrote:<br> <blockquote id="isReplyContent" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
Hi Xiaochao,<br>
<br>
The key point for us is how to count the NPE. SDU_3 module light
yield is about 400 PEs, it's far lower than THU new module (more 700
PEs). The main reason maybe the define of Gain is different.<br>
<br>
The first attached picture is the SP and SK values for my ten PMTs
which provided by Hamamatsu company, few of them used for our
detector. The second form puts the sp and sk of Hamamatsu and our
test result together. <br>
<br>
We can find that our GAIN at 1500V is not proportional to Sp/Sk. We
also provide the voltage for gain at 1E6, 2E6 and 4E6. We use
single photon electron method to define the Gain, not Sp/Sk. Which
method is reasonable? As we know, most particle experiment use
single photon electron to define Gain instead of Sp/Sk.<br>
<br>
Cunfeng <br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 2017/9/8 19:56, Xiaochao Zheng
wrote:<br>
</div>
<blockquote type="cite" cite="mid:252554895.6906165.1504871795461.JavaMail.zimbra@jlab.org">
<div style="font-family: arial, helvetica, sans-serif; font-size:
12pt; color: #000000">
<div>Hi Cunfeng:<br>
</div>
<div><br data-mce-bogus="1">
</div>
<div>Please see attached. At this moment I don't think it's
important to discuss what the value of b is and whether it is
reasonable, although I think data shows the power of b works.
(We could test another PMT (perhaps SDU lab can do this) and
see if it exhibit the same behavior. )<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>The important issue is how do we understand Chendi's
shashlyk data. Any idea?<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>Thanks,<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>Xiaochao<br data-mce-bogus="1">
</div>
<div><br>
</div>
<hr id="zwchr" data-marker="__DIVIDER__">
<div data-marker="__HEADERS__">
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"Xiaochao Zheng" <a class="moz-txt-link-rfc2396E" href="mailto:xiaochao@jlab.org"><xiaochao@jlab.org></a><br>
<b>To: </b>"cunfeng feng" <a class="moz-txt-link-rfc2396E" href="mailto:cunfeng.feng@cern.ch"><cunfeng.feng@cern.ch></a><br>
<b>Cc: </b>"Éê³ÀµÏ" <a class="moz-txt-link-rfc2396E" href="mailto:15600915869@163.com"><15600915869@163.com></a><br>
<b>Sent: </b>Friday, September 8, 2017 7:49:51 AM<br>
<b>Subject: </b>Re: [Solid_ec] calculation<br>
</blockquote>
</div>
<div data-marker="__QUOTED_TEXT__">
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">
<div style="font-family: arial, helvetica, sans-serif;
font-size: 12pt; color: #000000">
<div>within certain error bars. 8.1 works pretty well for
most of points.<br>
</div>
<br>
<hr id="zwchr">
<div>
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"cunfeng feng" <a class="moz-txt-link-rfc2396E" href="mailto:cunfeng.feng@cern.ch"><cunfeng.feng@cern.ch></a><br>
<b>To: </b>"Xiaochao Zheng" <a class="moz-txt-link-rfc2396E" href="mailto:xiaochao@jlab.org"><xiaochao@jlab.org></a><br>
<b>Cc: </b>"Éê³ÀµÏ" <a class="moz-txt-link-rfc2396E" href="mailto:15600915869@163.com"><15600915869@163.com></a>, "solid
ec" <a class="moz-txt-link-rfc2396E" href="mailto:solid_ec@jlab.org"><solid_ec@jlab.org></a><br>
<b>Sent: </b>Thursday, September 7, 2017 11:47:28 PM<br>
<b>Subject: </b>Re: [Solid_ec] calculation<br>
</blockquote>
</div>
<div>
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">
<p>simple calculate:</p>
<p>1.1^8.1=2.16, Gain at 1100V should be
3.1*2.16=6.7>6.5(chendi list)(3.1is the gain at
1000V)<br>
</p>
<p>1500V : 1.5^8.1=26.7,
=>G=3.1*26.7=82.7<102(chendi's)</p>
<p>So the relation not normally as G=a*V^b.</p>
<p><br>
</p>
<br>
<div class="moz-cite-prefix">On 2017/9/8 11:23,
Xiaochao Zheng wrote:<br>
</div>
<blockquote cite="mid:1272309214.6891221.1504841035204.JavaMail.zimbra@jlab.org">
<div style="font-family: arial, helvetica,
sans-serif; font-size: 12pt; color: #000000">
<div>Hi Cunfeng:<br>
</div>
<div><br>
</div>
<div>There is a slight difference here: When the
curve is linear on the double-log scale, one
could have: <br>
</div>
<div> gain = a * (HV)^b, where a and b are
constants. Looking at Chendi's data (see the
spreadsheet file on the minutes), the value of b
seems to be about 8.1, which is likely to be the
number of stages for this PMT. In this case, the
increase in the gain per dynode is linear with
HV, and the total gain is HV raised to the power
of number of stages, and thus Chendi's results
are reasonable and is consistent with what we
expect. <br>
</div>
<div><br>
</div>
<div>At the meeting JP said what CHendi showed
agrees with JP's experience. He said for the
Hall A HRS detectors, when the HV is increased
by fixed amount (such as 100V each time), the
gain increase by a fixed scaling factor (for
example, doubles every 100V). THis can be
either explained using the single log scale
function, or a power function as above.<br>
</div>
<div><br>
</div>
<div>So I think the problem may be elsewhere:<br>
</div>
<div>1) Can the PMT anode current saturate? <br>
</div>
<div>2) Can the attenuator that Chendi used behave
non-linearly?<br>
</div>
<div>3) If we do a HV scan for the SDU3 module, is
it possible to show the same (weird) behavior?
Can the SDU group do such a scan to prove the
method to be valid? (That we should get a fixed
Npe for different HV values)?<br>
</div>
<div><br>
</div>
<div>Thanks,<br>
</div>
<div><br>
</div>
<div>Xiaochao<br>
</div>
<div><br>
</div>
<div><br>
</div>
<hr id="zwchr">
<div>
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"cunfeng feng" <a class="moz-txt-link-rfc2396E" href="mailto:cunfeng.feng@cern.ch" target="_blank" moz-do-not-send="true"><cunfeng.feng@cern.ch></a><br>
<b>To: </b>"Éê³ÀµÏ" <a class="moz-txt-link-rfc2396E" href="mailto:15600915869@163.com" target="_blank" moz-do-not-send="true"><15600915869@163.com></a>,
"Xiaochao Zheng" <a class="moz-txt-link-rfc2396E" href="mailto:xiaochao@jlab.org" target="_blank" moz-do-not-send="true"><xiaochao@jlab.org></a>,
"solid ec" <a class="moz-txt-link-rfc2396E" href="mailto:solid_ec@jlab.org" target="_blank" moz-do-not-send="true"><solid_ec@jlab.org></a><br>
<b>Sent: </b>Thursday, September 7, 2017
10:56:18 PM<br>
<b>Subject: </b>Re: [Solid_ec] calculation<br>
</blockquote>
</div>
<div>
<blockquote style="border-left:2px solid
#1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;">
<p>Chendi,</p>
<p>I agree with Xiaochao that the Gain-V
relation is linearity under double-log axis
as shown on the PMT specification sheet, not
single-log axis. You should contact with the
PMT company to explain why the Gain-V
results is not linearity under double-log
axis.</p>
<p>Your PMT Gain raises much more, it should
be the reason the NPE decrease.<br>
</p>
<p>Cunfeng<br>
</p>
<br>
<div class="moz-cite-prefix">On 2017/9/7
22:26, Éê³ÀµÏ wrote:<br>
</div>
<blockquote cite="mid:625d2aec.d5e2.15e5cbbcbc5.Coremail.15600915869@163.com">
<div style="line-height:1.7;color:#000000;font-size:14px;font-family:Arial">
<div>hello</div>
<div><br>
</div>
<div>here is my calculation.</div>
<div><br>
</div>
<div>best regards<br>
</div>
<br>
<br>
<br>
<br>
<div style="position:relative;zoom:1">--<br>
<div style="font-family: 'lucida
Grande', Verdana, 'Microsoft YaHei';
font-size: 12px; line-height: 23.8px;"><i><span style="line-height: 22.1px;
font-size: small;"><span style="line-height: 22.1px;
font-family: ºÚÌå;">Éê³ÀµÏ </span><span style="line-height: 22.1px;
font-family: Arial;"> Chen-di
Shen</span></span></i></div>
<div style="font-family: 'lucida
Grande', Verdana, 'Microsoft YaHei';
font-size: 12px; line-height: 23.8px;"><span style="line-height: 22.1px;
font-family: Arial; font-size:
small;"><i>Department of Engineering
Physics, Tsinghua University</i></span></div>
<div style="font-family: 'lucida
Grande', Verdana, 'Microsoft YaHei';
font-size: 12px; line-height: 23.8px;"><span style="line-height: 22.1px;
font-family: Arial; font-size:
small;"><i><span style="line-height:
23.8px;">418, Liuqing Building,
THU, Haidian District, Beijing,
China,</span><span style="line-height: 23.8px;"> </span><span style="line-height: 23.8px;
border-bottom-width: 1px;
border-bottom-style: dashed;
border-bottom-color: rgb(204,
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1px; border-bottom-style:
dashed; border-bottom-color:
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1;">100084</span></span></i></span></div>
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font-size: 12px; line-height: 23.8px;"><span style="line-height: 22.1px;
font-family: Arial; font-size:
small;"><i><span style="line-height:
23.8px;">Tel£º86-</span><span style="line-height: 23.8px;
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border-bottom-style: dashed;
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204, 204); z-index: 1; position:
static;"><span style="border-bottom-width:
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rgb(204, 204, 204); z-index:
1;">15600915869</span> & <span style="border-bottom-width:
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1; position: static;">86-18101259887</span></span></i></span></div>
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font-size: 12px; line-height: 23.8px;"><span style="line-height: 22.1px;
font-family: Arial; font-size:
small;"><i>email: <a href="mailto:shenchendi404@qq.com" target="_blank" style="outline:
none; cursor: pointer; color:
rgb(99, 72, 25);" moz-do-not-send="true">shenchendi404@163.com</a></i></span><br>
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