<!-- Title: 13:20:01  Mon Aug 27 2007 -->
<!-- Crewchief: Ignacio (alphanumeric) -->
<!-- Op1: Jose (SPL on call) -->
<!-- Op2: &nbsp; -->
<!-- Op3: &nbsp; -->
<!-- Op4: &nbsp; -->
<!-- Op5: &nbsp; -->
<!-- Op6: &nbsp; -->
<!-- Notes: -->
Fourth week of the shutdown. The plugs are open, the tents are operational since Wednesday, and the repair work on the East ISL portcard lines continues.


<!-- Date: Mon Aug 27 18:32:48 2007 -->
 
<h3>Bore Access for Leak Repair: Day 4</h3> 
 
The plan for the morning is to inspect the coating of the return 
manifold done on Saturday and continue with a second layer of epoxy on 
the supply manifold. More plans will be made as we go along. We have 
to shift our time plan a little, because there will be work on the 
iFix PC from 7:00 to 9:00 in the morning. 
 
<ul> 
 
   <li><b>8:00</b>: Changing SVX chiller set point back from -6°C to 
   -3°C. Nitrogen flow to Silicon volume reduced (SVX) or shut off 
   (ISL). At the same time KC starts to work on the SVX resin bed. The 
   SVX conductivity surpassed 20 μS/cm over the weekend. 
 
   <li><b>9:10</b>: Ken and Peter enter the bore. They discovered that 
   the Velcro that holds the tent door in place has opened, so that the 
   door was half open. They could not find anything suspicious with the 
   COT baggie, so we still don't understand why all East dew points 
   dropped early Sunday morning. When the bore work started, the baggie 
   dew points shot up to -12°C when Ken and Peter opened the East 
   Silicon baggie before starting the blower on the West side, but 
came down 
   after a few seconds. Things look stable now. 
 
   <li><b>10:45</b>: Ken has difficulties depositing the epoxy and 
   suspects that temperatures are different than before. The set points 
   are as they were last week, but the local temperatures are not. The 
   ISL PCE temperatures are 2-3°C colder than on Friday, despite 
   the warmup 2.5 hours ago. Checking the history, the temperatures 
   would not follow the cool-down Saturday at noon, but rather drop 
   only 16 hours later, around 4:00 on Sunday morning (at the same time 
   when the dew points dropped). 
 
   <li><b>11:30</b>: Lunch break and discussion about further 
   plans. Fixing the West portcard line has higher priority than 
   investigations of ladder cooling lines. We will try and finish the 
   East portcard lines today, so that they can be be pressure-tested 
   tomorrow. Then we will move equipment to the West side and start 
   pulling out the Cilran tubes. 
 
   <li><b>13:15</b>: After a few minutes of bore work, Ken and Doug 
   come back. The environment is too cold to press the epoxy out of the 
   brass tube. We tried to learn more about the mechanism, but it still 
   is quite a mystery. Sunday morning at 4:00 the ISL PCE temperature 
   dropped. At the same time, the ISL PCW temperature (which was a 
   little colder than PCE), went up. Also the probe on the West ISL 
   space frame at 270° went down, but the East ISL space frame was 
   unchanged. It looks like a problem with the ambient temperature, so 
   we checked external parameters. We did not find any significant 
   changes in tent temperatures and humidities, collision hall 
   temperatures and humidities, COT inner diameter and end plate. We 
   have warmed up ISL from 10°C to 15°C. Other options to warm 
   up the PCE cooling lines include flowing warm gas through the line 
  and increasing the West tent temperatures. 
 
   <li><b>16:00</b>: Peter calls from the bore and lets me know that 
they 
will be playing around a bit with the west tent temperatures. A few 
moments later 
the west tent temperatures began to rise. By 16:35, temperatures are 
up to 21°C 
in the west tent. Unfortunately, temperatures haven't risen as 
quickly as planned, and 
work will continue in the morning. </li> 
 
</ul> 
 
The <a 
href="http://b0sili01.fnal.gov/cgi-bin/TWiki/bin/view/Silicon/ 
BoreMoviesShutdown">TWiki 
page with the bore movies</a> has been updated accordingly. 
 
 
With love, 
 
  
<!-- Author: Jennifer :-) for the ISL repair crew -->


<!-- Date: Mon Aug 27 18:38:02 2007 -->
We noticed that the east SVX nitrogen flowmeter is leaking when we increased the flow from 60 to 95 for overnight.
<!-- Author: Ignacio/Jose -->


<!-- Date: Tue Aug 28 08:19:05 2007 -->
From Cryo e-log: 
<pre> 
Sample from SVX taken this morning shows conductivity of 18.5µS/cm and a pH of 4.10 - Bill Noe 
</pre> 
The controller is still saturated (above 20 muSi/cm).
<!-- Author: Ignacio -->


<!-- Date: Tue Aug 28 13:03:47 2007 -->
Warren has swapped the east SVX nitrogen flowmeter during the lunch break.
<!-- Author: Ignacio -->


<!-- Date: Tue Aug 28 19:00:42 2007 -->
<h3>Bore Access for Leak Repair: Day 5</h3> 
 
<ul> 
 
  <li><b>10:00</b>: We start a little later because of work on one of 
  the iFix PCs downstairs (S3). The temperatures were stable overnight 
  and probably still a little too low to be successful depositing 
  epoxy. The ISL chiller set point is the only parameter in the system 
  for which we know that it work and that we are comfortable changing 
  (unlike the SVX chiller set point). We also know that the 
  conductivity in ISL is very low and stable. So we warm up ISL to 
  20°C. In the course of doing this we had cryo alarm on chiller 
  evaporator and outlet temperature. We would have silenced those, but 
  this was happening while S3 was still being worked on. 
 
  <li><b>10:10</b>: When we turned down the nitrogen, we saw another 
  strange reaction of the system. The ISL PCE temperatures went down 
  instead of up, and so did the West ISL space frame temperature at 
  270°. Our only explanation at this point is: the local temperature 
  changes when nitrogen is blown out of the colder SVX volume into 
  the warmer ISL volume. So there are (at least) two effects at work: 
  the warm ISL system operates as a heater, and the cold SVX system 
  operates as a cooler. The heat is transported via the gas flow 
  inside the volume. 
 
  <li><b>10:45</b>: First report from the bore: the Cilran tubes 
  are warm enough to work with them. Seems that it takes the tubes 
  (bad heat conductors) a day to warm up after the SVX temperature 
  set point change. We continue to run the West tent dehumidifier 
  a little warmer than th East, now at 22°C. 
 
  <li><b>11:35</b>: The SVX nitrogen flow goes into alarm. As it turns 
  out, Del decided to look into the leak in the instrumentation. We 
  give the go-ahead for a quick repair of the leaky 
  instrumentation. Now the nitrogen flow to SVX is out of alarm. 
 
  <li><b>13:30</b>: Ken and Peter go back into the bore to finish 
  epoxy work on the supply side and a pressure test of the manifolds. 
  We will hook up the large resin bed to the SVX circuit later today 
  to fight the increase in conductivity and the pH reduction. The 
  temperature profile of SVX for the last month is as follows: 
  <table border='1' cellpadding='2'> 
    <tr><th>Date</th><th>Temperature (°C)</th><th>Comment</th></tr> 
    <tr><td>Until 08/06</td><td align='right'>-10</td><td>Data Taking</td></tr> 
    <tr><td>08/06 - 08/08</td><td align='right'>-6</td><td>Start of Shutdown</td></tr> 
    <tr><td>08/08</td><td align='right'>-10</td><td>Cosmics Run</td></tr> 
    <tr><td>08/08 - 08/14</td><td align='right'>-6</td><td>Shutdown Mode</td></tr> 
    <tr><td>08/14</td><td align='right'>-3</td><td>Drain and Flush</td></tr> 
    <tr><td>08/14 - 08/15</td><td align='right'>-6</td><td>Shutdown Mode</td></tr> 
    <tr><td>08/15 - 08/17</td><td align='right'>0</td><td>Plug Pull</td></tr> 
    <tr><td>08/17 - 08/25</td><td align='right'>-3</td><td>ISL Repair</td></tr> 
    <tr><td>08/25 - 08/27</td><td align='right'>-6</td><td>ISL Repair Weekend</td></tr> 
    <tr><td>08/27 - Now</td><td align='right'>-3</td><td>ISL Repair</td></tr> 
  </table> 
  The conductivity started increasing fast on 08/21, around 9:30, 
  out of the blue. 
 
  <li><b>14:10</b>: It is still to difficult to deposit epoxy on the supply. 
  We will have to try and heat the Cilran with hot gas. The preparation for 
  this jobs takes quite some time, especially avoiding safety hazards in 
  the bore. Around 17:00 the gas heater is ready to go. The heating 
  is tested and works well. We decide to let the epoxy cure until tomorrow, 
  heat again and finally finish up the East side. 
 
  <li><b>16:30</b>: Dean and KC connect the large resin bed to the SVX 
  cooling circuit. All parameters are fine, except for the the pressure 
  drop across the filters and the chiller discharge pressure, which are 
  higher than normal (as expected). The resin bed seems to work well. 
  After less than two hours, the conductivity is already down to 
  below 9 μS/cm. 
 
  <li><b>17:30</b>: Jose, Doug, and Ulrich identified the positions of 
  the RTDs on the portcard rings. The names "IN" and "OUT" correspond to 
  the z position, "OUT" has the larger |z|. There are RTDs at 
  <a href="http://hepdhcpd.physics.ucsb.edu/~stuart/lgbk/E10079.JPG">180°</a>  
  and at <a href="http://hepdhcpd.physics.ucsb.edu/~stuart/lgbk/E10095.JPG">0°C</a> (we don't know yet if "1" is north and "2" is south or vice versa). 
 
 
</ul>
<!-- Author: The ISL Repair Crew -->
<!-- Comment: Wed Aug 29 11;39;30 comment by...Ankush -->
<pre>Doesn't the IN and OUT follow the same convention on the Junction Card Ring ?</pre>
<!-- Comment: Wed Aug 29 11;44;18 comment by...Ulrich -->
London must be boring... What was the JC ring convention again? We got the IN and OUT from Doug's CDF note 5553 (ISL Maps), page 12.
<!-- Comment: Wed Aug 29 11;59;57 comment by...Ankush -->
<pre>Well London is very nice at the moment. Clear skies and sunny !!

I can't remember the convention off the top of my head.  But there are notes in my log book (which our SPLs should have a copy of).  

You should find my log book in my office sitting on the shelf above my computer.  It's the standard soft-cover Fermilab log book.  Have a look through that. (I also guess this probably gives the same info as Doug's CDF note.)</pre>
<!-- Date: Tue Aug 28 20:18:48 2007 -->
<h4>Silicon's very own Amazon</h4> 
By popular demand, here are the videos: 
<p> 
<a href="http://www.youtube.com/watch?v=RVtrbl8_Yxs">Arm-over-arm chain pull</a> and <a href="http://www.youtube.com/watch?v=kZdNEKM5xS8">Yoke & Tire-flipping madness</a>.
<!-- Author: Mme. Pink :-) -->
<!-- Comment: Wed Aug 29 09;29;13 comment by...Monsieur Rouge -->
You didn't tell us you were married, Madame Pink! Can Charles call you Ma'am now?


<!-- Comment: Wed Aug 29 11;02;52 comment by...She who *clearly* speaks NO French. -->
Haha, woops! I was just going by my silicon cafe nickname :-)
<!-- Date: Wed Aug 29 09:29:30 2007 -->
They fixed yesterday the 400 Hz power. We have switched on the silicon racks.
<!-- Author: Jose -->
<!-- Comment: Wed Aug 29 17;24;32 comment by...Jose -->
Fibs have been rebooted.
<!-- Date: Wed Aug 29 14:16:05 2007 -->
<table><tr><td><a href=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11796&button=yes target='xxx' onclick='jswindow()'; align=top><img src=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11796  width='300' align='top'></a></td><td>Profile of the temperatures of SVX during a 8h power outage. At that point, the set point for SVX was -10 C. After 8h the temperature was close to +10C. More plots following the link <a href=http://www-cdfonline.fnal.gov/cgi/internal/elog/det-system-elog.pl?nb=silicon&action=xe&page=292&time=18:04:40> March 18th 2006</a>.</td></tr></table>
<!-- Author: Ulrich and Jose -->


<!-- Date: Wed Aug 29 14:32:38 2007 -->
PS GUI died under our eyes. Not clear what the reason was, apparently SVXINTER was sending setPSStatus signals without reason. We rebooted SVXINTER, and it could not connect to the RTServer. The Ace restarted the RTServer at our request, and now everything is back up.
<!-- Author: Jose & Ulrich -->


<!-- Date: Wed Aug 29 14:47:08 2007 -->
<h3> We will have our weekly meeting this Friday: 
<li> Time : 2pm 
<li> Location : Trailer 159 
</h3>
<!-- Author: Ignacio and Jose -->


<!-- Date: Wed Aug 29 15:56:44 2007 -->
<h3>Bore Access for Leak Repair: Day 6</h3> 
 
<ul> 
 
  <li><b>8:40</b>: We start the day with a cooling trip. After we ran 
  the large resin bed over night, the conductivity stabilized around 
  1.2 μSi/cm. Bill had changed the set point for the pneumatic 
  valve to the resin loop from 2.0 μSi/cm to 0.5 μSi/cm to force 
  the valve open all the time. This accelerated the reduction of 
  conductivity nicely.<br> 
 
  Bill and his crew exchanged resin this morning to reduce the 
  conductivity even more. For the regular resin bed they followed 
  their procedure, which includes opening the bypass loop in the 
  filter circuit. This is perfectly alright under normal 
  circumstances, but was fatal with the additional resin bed.  To 
  force more flow to the additional resin bed, we throttle the flow to 
  the other filters by partly closing SVX MV 2013 W. The bypass loop 
  bypasses that valve and abruptly puts the full pressure back on the 
  system. That tripped the flows because one or more of the COT face 
  pressures were too high. It was very easy to get the flow back. 
 
 
  <li><b>9:00</b>: Ken and Andy start working in the bore. Ken had 
  left a nitrogen purge running over night, so we found all ISL PCE 
  temperatures equalized nicely around 13.5°C this morning. Ken 
  and Andy switched on the gas flow, and the temperatures went up to 
  around 16°C within 15 minutes. A little later they turned 
  on the heater, and the temperatures increased to 17°C. 
  Ignacio's impression was that there is another effect at work: 
  the portcards warmed up as a late consequence of the SVX trip, 
  the small decrease in temperature after that is because of 
  the cool-down. In the end the heater takes over. 
 
  <li><b>13:30</b>: Ken and Doug continue with the ISL work. The 
  plan is to deposit more epoxy. The portcard ring is being heated 
  even more, now above 18°C. The temperature trip limit is currently 
  at 22°C. The inspection showed that the return side looks very good. 
  The supply side got some more coating. We will do final tests on 
  the East side tomorrow and then move on the West portcard lines. 
  We will leave the nitrogen heater on over night. If any temperatures 
  are getting too hot, we will have iFix alarms to the alphanumeric pager. 
 
</ul>
<!-- Author: The ISL Repair Crew -->
<!-- Comment: Wed Aug 29 16;46;22 comment by...Ulrich -->
Correction: the ISL portcard trip limit from the PLC was at 20°C. I've bumped it up to 24°C, just as for the ladder cooling lines.

<!-- Comment: Wed Aug 29 17;21;17 comment by...Ulrich -->
Surprise: the ISL portcard temperatures were not monitored by <tt>alarms.exe</tt>. Why??? Anyway, I've added them to the list of iFix tags to be monitored, since we certainly want to be woken up should the hot gas blower get crazy. The current iFix limits are 21°C (warning) and 22°C (alarm). The PLC will trip at 24°C.
While I was at it, I also added the second pair of Silicon baggie dew point variables (the former SVX and ISL dew points) to the list of SVX alarms. The current warning limit is at -10°C and the alarm is at -8°C.
<p>
I have also adjusted the lower warning limit for the L00 vacuum jacket temperatures
from 17°C to 15°C and the ISL chiller return temperature limits from 17/18°C to 23/25°C.





<!-- Date: Thu Aug 30 13:41:37 2007 -->
The SVX/L00 conductivity went into warning because the conductivity is smaller than 1 muSi/cm. I have ignored the alarm.
<!-- Author: Ignacio -->


<!-- Date: Thu Aug 30 17:22:42 2007 -->
<h3>Bore Access for Leak Repair: Day 7</h3> 
 
<ul> 
 
  <li><b>8:50</b>: The hot gas blower worked fined over night, with 
  temperatures stable between 18°C and 19°C. The plan for this 
  morning is to do an inspection of yesterday's coating efforts. Del 
  will do his pressure test on ISL PCW. This time he managed to stay below 2 
  psig without problems. He sees more flow than on the East, but at a 
  lower pressure. He needs to do some calculations to get quantitative 
  results. 
 
  <li><b>9:30</b>: Dean, KC, and Bill realize that the new resin 
  bottles that use cardridges has the same threading as the old bottles. 
  So they simply replaced them without any plumbing. They only need 
  new insulating shoes. It seems that the flow to the detector is 
  slightly lower after the change. The CCE1 flow dropped a little, but 
  it may just have been on the edge. 
 
  <li><b>11:30</b>: The inspection showed that all eight portcard ring 
  protrusions are well covered in epoxy, maybe with the expection of the 
  front right supply tube. Despite the additional epoxy, the pressure 
  test shows the same results as yesterday. A pressure test was 
  attempted on a plain Cilran tube to see if there is a flaw in the 
  test or if there are more leaks. The test works, so the remaining 
  leak is real. 
 
  <il><b>13:30</b>: Ken and Doug return to the bore. They will re-examine 
  the front supply tubes and add epoxy if required. The examination with 
  the right-angle view scope showed small pittings inside the oval 
  tubes as well, still in the heat-affected area. Ken applied and smear 
  epoxy inside the tube. We'll have to wait for the pressure test 
  to see if this helped. 
 
  <li><b>16:00</b>: The SVX supply pressures are on the low side due 
  to the 10 psid pressure drop across the big resin bed. We opened up 
  the e-valves for BHE1, BHE2, L00E, and L00W above their nominal 
  values. <em>We need to turn them back to nominal before we valve out 
  the big resin bed</em>. We have also change the lower warning limit 
  on the supply pressures (SVX_PT_DETESUP, SVX_PT_DETWSUP) from 20 psia 
  to 18 psia and the lower alarm/warning limits for the conductivity 
  from whereever they were to 0.0/0.1, as a lower limit on conductivity 
  does not make much sense. 
 
  <li><b>16:30</b>: Ken and Doug move over to the West bore to start 
  fishing the Cilran tubes out of the Silicon baggie. As a first step, 
  they have cut the tube outside the baggie and inserted a small wire 
  to figure out how the Cilran tubes are routed inside the 
  baggie. They managed to cut both the supply and the return tube and 
  pulled the supply tube out of the baggie. They will continue with 
  pulling out the return tube tomorrow. Then there will be the 
  (hopefully) final pressure test on the East side. Starting time: 8:30. 
 
</ul>
<!-- Author: The ISL Repair Crew -->


<!-- Date: Thu Aug 30 18:29:19 2007 -->
PSGui lost communication with iFix for a minute. To check if the PSGui was running or not I pressed enter in the PSGui terminal and this opened a new PSGui. This should be prevented by the lock file, but it did not... Unfortunately, I had to kill both PSGui to get one running properly. Now everything is back to normal.
<!-- Author: Jose -->


<!-- Date: Thu Aug 30 18:36:13 2007 -->
I have ignored for now the SVX BHE1 supply flow. It was oscillating around 2.2 lpm and going to warning.
<!-- Author: Jose -->


<!-- Date: Fri Aug 31 07:54:01 2007 -->
PSGUI crashed overnight loosing connection as usual. Now running on b0dasvx01. 
<pre> 
<svxii@b0dasvx03>PS & 
[1] 17145 
<svxii@b0dasvx03>User: svxii 
Display: 
Attempting initialization of CAEN at svxinter.fnal.gov... 
Downloading /cdf/onln/data/svxii/caencontrol/PSfilesNew/PS.conf 
Loading startup files to the server.....Please be patient 
GUI Startup Done! 
9168: gss_init_context failed 
[svxii@b0dasvx01 PSfilesNew]$ pwd 
</pre>
<!-- Author: Ignacio -->


<!-- Date: Fri Aug 31 16:59:57 2007 -->
<h3>Bore Access for Leak Repair: Day 8</h3> 
 
<ul> 
 
  <li><b>8:45</b>: The nitrogen flows are ready to go. Ken and Doug start 
  on the West side and fish out the return tube. Then they will continue 
  with a pressure test on the East side. We will also have a meeting 
  around lunch time to make a plan for the long weekend and the power 
  outage on Tuesday. 
 
  <li><b>10:00</b>: The return tube turned out to be easy to fish out. 
  Ken and Doug move back to the East side for a pressure test and an 
  inspection of the hole inside one of the tubes that was discovered 
  and filled with epoxy yesterday. 
 
  <li><b>11:30</b>: 
  During a short meeting we discussed the plans for the long weekend: 
  <ul> 
 
    <li>Today: extend nitrogen line into West tent to connect to Cilran tubes, 
    Snoop test, more epoxy, run heater overnight (East)</li> 
     
    <li>Saturday: close COT and Silicon baggies (need extension for 
    supply tube), keep heater running (if more epoxy is deposited), move 
    power cord for heater outside bore, establish nominal COT baggie 
    nitrogen flow. If no epoxy deposited: heater switched off, valve out 
    large resin bed, cool down SVX to -6°C and ISL to 
    +6°C. </li> 
     
    <li>Sunday (only if epoxy was deposited on Saturday): heater 
    switched off, valve out large resin bed, cool down SVX to -6°C 
    and ISL to +6°C.</li> 
     
  </ul> 
 
<li><b>13:30</b>: Good news from the bore. Ken and Peter 
  conducted a Snoop test to see if any joints are still leaking. They 
  found that the edge of the epoxy on the rear left return tube 
  (the one with the large pitting) is leaking. They cleaned the area 
  with alcohol, let it dry now and will apply more epoxy later today. 
 
<li><b>14:30</b>: Ken and Peter applied another two rounds of epoxy 
  to the rear left return tube. We are pretty confident that this 
  will finally fix the leak. We will continue tomorrow morning 
  at 9:00 with a pressure test and maybe some inspection on the West 
  side. 
   
</ul>
<!-- Author: The ISL Repair Crew -->


<!-- Date: Sat Sep 1 08:48:45 2007 -->
I've rebooted SVXIICON yesterday evening. It was anyway due todoy, and I had made a mistake and force-quit FTTrend, which blocked the serial port, so I could not use SoftShop to start the PLC backup for the power outage on Tuesday.
<!-- Author: Ulrich -->


<!-- Date: Sat Sep 1 15:54:45 2007 -->
<h3>Bore Access for Leak Repair: Day 9</h3> 
 
<ul> 
 
  <li><b>9:30</b>: Ken and Peter continue the bore work. First they 
  did a pressure test to check if the additional epoxy on the 
  rear left joint of the return manifold improved the air tightness 
  of the system. That joint had shown significant bubbles 
  during a Snoop test yesterday afternoon. Unfortunately, the 
  result of the pressure test is the same as yesterday. 
 
  <li><b>10:30</b>: A more detailed pressure test showed that 
  the <b>rear portcard ring is now leak-free</b>! The 
  Snoop test did not reveal any other obvious leaks. From 
  more careful inspections of the front tubes, there are two 
  suspicious spots left, both on the left front tube. There 
  is one sizable black spot and one thing that could be just 
  a scratch but may well be a crack. Both are worth putting 
  new epoxy on. Now that we know that the rear ring is tight, 
  we can learn more from isolating parts of the front rings 
  in additional pressure tests. From watching the videos we 
  concluded that the front return tubes look rather good, but the 
  we could not really see inside the front left one. 
 
  <li><b>11:45</b>: Ken and Peter did more pressure tests, 
  and they seem to be conclusive. Peter defined eight locations 
  along the tube, at which we can position the catheter for 
  the pressure test (see also the sketch below), numbered 1-4 
  for the supply and the return line: 
  <ol> 
    <li>before the front portcard ring 
    <li>sealing the front portcard ring 
    <li>between the front and the rear portcard ring 
    <li>at the accessible end of the Cilran tube 
  </ol> 
 
  The result of the pressure test was as follows: 
  <table border=1 cellpadding=2> 
    <tr><th>Test Number</th><th>Supply Position</th><th>Return Position</th><th>Rate</th><th>Result</th></tr> 
    <tr><td align=center>0</td><td align=center>3</td><td align=center>3</td> 
    <td>stable at 30 in WC for 5 minutes</td><td>Rear ring is leak-free</td></tr> 
    <tr><td align=center>1</td><td align=center>3</td><td align=center>2</td> 
    <td>30 in WC → 2 in WC / 2 minutes</td><td>Catheter balloon seal at position 2 is not perfect</td></tr> 
    <tr><td align=center>2</td><td align=center>4</td><td align=center>2</td> 
    <td>30 in WC → 5.8 in WC / 2 minutes</td><td>Leak must be in front ring of return</td></tr> 
    <tr><td align=center>3</td><td align=center>2</td><td align=center>4</td> 
    <td>30 in WC → 0 in WC / 30 seconds</td><td>Leak is not in front ring of supply</td></tr> 
    <tr><td align=center>4</td><td align=center>2</td><td align=center>2</td> 
    <td>30 in WC → 0 in WC / 30 seconds</td><td>Inconclusive, balloon seal difficult</td></tr> 
    <tr><td align=center>5</td><td align=center>2</td><td align=center>2</td> 
    <td>30 in WC → 20 in WC / 50 seconds</td><td>Inconclusive, balloon seal difficult</td></tr> 
    <tr><td align=center>6</td><td align=center>2</td><td align=center>1</td> 
    <td>30 in WC → 0 in WC / 30 seconds</td><td>Leak is downstream of position 1 in return</td></tr> 
    <tr><td align=center>7</td><td align=center>2</td><td align=center>2</td> 
    <td>slow</td><td>Rear ring is tight, seal not perfect</td></tr> 
    <tr><td align=center>8</td><td align=center>1</td><td align=center>2</td> 
    <td>slow</td><td>Leak must be in front ring of return</td></tr> 
    <tr><td align=center>9</td><td align=center>1</td><td align=center>1</td> 
    <td>30 in WC → 0 in WC / 30 seconds</td><td>Leak in manifold, not Cilran tube</td></tr> 
  </table> 
 
  The conclusion of all of this: <b>The remaining leak must be at the front joints of the return manifold.</b> 
   
  For all of you who grew up with SI units, 30 inches of water column 
  is equivalent to 0.762 m of water column or 74.7 hPa or 0.0747 bar 
  or 1.08 psi. 
 
  <li><b>13:30</b>: After the above pressure test, Ken and Peter tried 
  to identify the leak with Snoop once more, but without success. So 
  they cleaned the manifolds with alcohol and blew them dry. They 
  suspect that the hole is too big for Snoop bubbles to be formed. 
 
  <li><b>14:30</b>: Ken and Peter pursued a new idea: they applied 
  epoxy while creating a vacuum on the supply side. This way bubbles 
  would show up in the epoxy at the point of the leak. And indeed, 
  they found a spot behind the front left tube with bubbles. They 
  applied a second layer of coating, applied pressure to dog-bone the 
  coat, and did a quick leak test at 16 in of water column. The good 
  news: <b>The system holds the pressure!</b>. At this point we are 
  very confident that we have successfully fixed the leak on the East 
  side (but we've said that before...). Come and join us tomorrow 
  at 8:00 to perform the (hopefully final) pressure test and 
  prepare everything for the power outage. 
 
</ul>
<!-- Author: The ISL Repair Crew -->
<!-- Comment: Sat Sep  1 16;08;35 comment by...Ulrich -->
13 GB of <a href="http://b0sili01.fnal.gov/cgi-bin/TWiki/bin/view/Silicon/BoreMoviesShutdown">video footage</a> so far, and that is only the East Portcards. The West and the ladder cooling lines are still to come...
<!-- Comment: Sat Sep  1 19;47;21 comment by...Ulrich -->
<p>
Schultz's first law of  Silicon Cooling: <em>There is always one more leak!</em> I just had the empirical proof on the front tire of my bike.  Was an easy fix, just swapped out the tube.
<!-- Comment: Sat Sep  1 21;31;03 comment by...Leak Tester -->
Holds 2 hours at 120 in WC!
<!-- Date: Sat Sep 1 15:56:36 2007 -->
<table><tr><td><a href=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11797&button=yes target='xxx' onclick='jswindow()'; align=top><img src=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11797  width='300' align='top'></a></td><td>Peter's scheme for positions in the Portcard cooling lines.</td></tr></table>
<!-- Author: Ulrich -->





<!-- Date: Sun Sep 2 10:25:28 2007 -->
<h3>Bore Access for Leak Repair: Day 10</h3> 
 
<ul> 
 
  <li><b>8:10</b>: Ken and Peter are back in the bore for a 
  (hopefully) final pressure test of the East ISL portcard 
  ring. Yesterday we confirmed that the rear portcard ring is already 
  leak-tight (held 30 in WC for 30 minutes), and we believe that the 
  filled the last remaining hole after that. 
 
  <li><b>8:50</b>: The pressure test showed a rate of drop of 7.5 
  inches of water column (from 30 in WC) over 5 minutes. That is not 
  completetly leak tight but much better than yesterday (30&rarr;0 in 
  WC in 30 seconds). We will discuss if we want more epoxy before 
  we move to the West side in a meeting on Wednesday morning. 
  Ken believes that the small leak could be from overpressurizing 
  the system with the heated nitrogen over night. 
  We will start the preparation for the power outage now, 
  including buttoning up the Silicon baggie and the COT baggie, 
  re-establishing nominal flow to the COT baggie, switching off 
  the dehumidifiers. We silence all tent-related HVAC alarms. 
 
  <li><b>10:00</b>: We have valved out the large resin bed on the SVX 
  cooling circuit. In order to avoid trips and alarms we first changed 
  the ProSys flow alarm limits to 1 lpm and then dialed down the 
  e-valve settings to 5-10% below their nominal values. Next we 
  carefully closed ISL MW 2013 W in order to allow the chiller bypass 
  to follow. Then we closed first the supply and then the return side 
  of the flow loop to the large resin bed and all internal valves on 
  the resin bed. After that we could go back to nominal e-valve 
  settings. 
 
  <li><b>10:10</b>: The baggies check out fine, so we reduce the 
  SVX and ISL temperatures: -6&deg;C (SVX) and 10&deg;C (ISL). 
  The ISL conductivity shoots up to 4-5 &mu;Si/cm, probably because 
  temperature correction of the controller is not tuned properly. 
 
</ul> 
 
The next step will be a short planning meeting on Wednesday morning at 10:00.
<!-- Author: The ISL Repair Crew -->


<!-- Date: Mon Sep 3 11:59:42 2007 -->
<table><tr><td><a href=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11798&button=yes target='xxx' onclick='jswindow()'; align=top><img src=/cgi/elog/det-system-elog.pl?nb=silicon&action=view&page=-11798  width='300' align='top'></a></td><td>The conductivity is on its way down after it shot up during the cool-down yesterday, now at 9.7 μSi/cm. I have also adjusted all vacuum jacket temperature lower warning limits that I hadn't changed before from 17°C to 15°C. This should finally bring those guys out of warning for good.</td></tr></table>
<!-- Author: Ulrich -->