<html><body><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000"><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">I will just skip to the chase, so to say. The following RICH design feature will severely limit cooling flow to the enclosed electronics package. FYI, my responses are in blue.</span><br></div><div><br data-mce-bogus="1"></div><div>--> DSG: The space inside the RICH case is limited:<br> we assume to split the 1 inch tube into few<br> smaller (9-10 mm diameter) plastic tubes for<br> the last part of the line. This may correspond<br> to the ~4m from the patch panel till the electronic<br> panel. Which is the maximum pressure we should<br> aim in this last part of the line ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">How many 4 meter long small ID lines have you determined will fit? Do you have drawings showing the required path and connections? I would offer a guess that you will need at least 15 each of the 4 meter long 3/8" (9mm) lines to flow 300 slm cooling flow. How many lines can be fit? Typically, using smaller lines in place of a larger one requires significantly more space than the single large line would. This is due to the space taken up by the tubing wall thickness. At some point, you are basically just filling up the space with nylon.</span><br></div><div><br data-mce-bogus="1"></div><div><br> --> DSG: is the current line from tank to RICH<br> suitable for maximum 283 slm (due to the<br> proposed rotameter) ? How complicate is to<br> upgrade it to reach 400 or 600 slm maximum ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Components have been changed to increase flow capacity;</span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">85-850 slm Flow Meter with Manual Valve </span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">0-1000 slm Mass Flow Meter</span><br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">But, in order to increase cooling flow to these higher values, additional numbers of the small ID tubing will be needed. This design feature will limit cooling flow capacity and require higher pressure air at the RICH box interface for the cooling air supp</span>ly.<span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);"> I recommend we analyze the space available and design some sort of duct to carry the cooling air flow in place of small ID tubing</span>.<br></div><div><br data-mce-bogus="1"></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">This design issue with the RICH is the limiting factor for electronics air cooling flow and should be analyzed further. </span><br data-mce-bogus="1"></div><div></div><div><br data-mce-bogus="1"></div><div>---------------------------------------------------------------------------------------------------------------<br data-mce-bogus="1"></div><div>--------------------------------------------------------------------------------------------------------------<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Now, on to the less exciting topics.</span><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>--------------------------------------<br>Cooling + Interlock<br>--------------------------------------<br>The inlet lines are designed for a typical flux of 100 slm,<br>and a 1 inch size. This flux was tested in a half-size<br>prototype and in a simplified heat load configuration. We<br>would therefore suggest to plan a typical 250 slm with a<br>large safety coefficient (> 50 %).<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Components have been changed to increase flow capacity;</span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">85-850 slm Flow Meter with Manual Valve </span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">0-1000 slm Mass Flow Meter</span><br><br><br> --> DSG: it would be nice to have the presssure<br> sets of the relief valves and the pressure<br> regulators visible in the interlock sketch,<br> as done for the N2 line.<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">The Pressure System Engineer has not as yet specified this value.</span><br><br> --> DSG: should the line from compressor to tank<br> design to sustain the full compressor flux<br> (1200 slm) ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">A high pressure 1" line has sufficient capacity to flow > 1200 slm at pressure</span><br><br><br> --> DSG: do we need an interlock for maximum<br> pressure in the tank or in the inlet line or<br> everything is set by the relief valves ?<br> The compressor has its on interlocked limit.<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">I do not follow this.</span> <br><br> --> DSG: the tank you propose is fine with us.<br><br>The interlock logic is relative to the cooling circuit<br>functionality. Other anables for the HV and LV power<br>supplies should come from temperature sensors in few<br>relevant places, i.e. inlet, inner volume, exhaust, FTOF.<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">The Cooling Circuit Interlocks will prevent HV and LV operation unless the following are true;</span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">1) At least one compressor is operational</span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">2) Pressure in the air tank is > 80 psi</span><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">3) Cooling Air Flow > 100 (TBD)slm to the RICH (TBD = To be determined)</span><br><br> --> DSG: may you provide information on your<br> board controlling temperature and humidity<br> sensors ? We usually use SHT75 sensors form<br> sensiron<br> --> INFN: should provide detailed information<br> in the compressor and power supply<br> hardware controls.<br><br>--------------------------------------<br>Nitrogen line<br>--------------------------------------<br>We plan to refresh the full RICH volume, close to 5000<br>liters, in about one day. The current inlet lines are<br>able to provide a maximum of 7200 l/day, with almost a<br>50 % safety factor. We consider it a realistic starting<br>point. We would anyway need to minimize the RICH vessel<br>leaks.<br><br>The LN2 dewar provides a nitrogen with enough purity,<br>with a water content smaller than 0.002%. The filters<br>are just for safety.<br><br>We will need to monitor temperature + humidity with<br>sensors inside the RICH volume.<br><br> --> DSG: do we need an interlock logic for the<br> N2 line, i.e. a shutter to isolate the RICH<br> volume in case of problems ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Not required.</span><br><br> --> DSG: for example we would be in favor to use<br> humidity sensors to monitor the inlet line<br> quality (the N2 should be fine but we may<br> have leaks or breaks in the line).<br> May we implement those in an cRio interlock<br> logic ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Not required. Isolating the N2 supply would have the opposite effect.</span><br><br> --> DSG: do we need a interlock shutting the N2<br> line in case of over-pressure of the RICH<br> module or relief valves would be enough ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Not Required. The bubbler performs that function.</span><br><br> --> DSG: The RICH N2 inner volume is supposed to stay<br> at ~0.5-1 mbar higher pressure than atmospheric,<br> to prevent water flowing in. Is the bubble<br> control system sensible enough to prevent<br> over- or under-pressure ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">The bubbler will maintain pressure according to the oil fill level and acts as a check valve to prevent back flow.</span> <span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">FYI, 1 milibar = 0.4 inches water column.</span> <br><br> --> DSG: the N2 line starts with a LN2 dewar:<br> do we need dedicated equipement to prevent<br> moinsture along the line and/or injecting<br> low temperature gas inside the RICH ?<br><br><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Not required. The 5,500 liter capacity liquid N2 dewar is located at Bldg 96B, nearly 300 meters from the RICH and utilizes a thermal safety valve that prevents cold gas or cryogenic liquid from flowing into the house N2 supply lines.</span><br><br></div><div>------------------------------------------------------------------------------------------------------------------------<br data-mce-bogus="1"></div><div>------------------------------------------------------------------------------------------------------------------<br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">I believe this is very good progress and has improved our understanding of the challenges this detector has for us. </span></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);"><br data-mce-bogus="1"></span></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">However, It is very critical that we optimize the electronics cooling flow path at the RICH patch panel and inside the RICH box. The current design severely limits cooling flow volume..</span><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">Cheers,</span></div><div><span data-mce-style="color: #3366ff;" style="color: rgb(51, 102, 255);">George</span><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"MMarco Contalbrigo" <mcontalb@fe.infn.it><br><b>To: </b>"Tyler Lemon" <tlemon@jlab.org><br><b>Cc: </b>"rossi patrizia" <rossi@jlab.org>, "clas12 rich" <clas12_rich@jlab.org><br><b>Sent: </b>Wednesday, May 25, 2016 1:27:12 PM<br><b>Subject: </b>[Clas12_rich] May 23th Meeting Minutes<br></div><div><br></div><div data-marker="__QUOTED_TEXT__">Dear all,<br>let me first thanks again the DSG for the essential support they<br>are giving to the project.<br><br>During May 23th meeting we reviewed various aspects of the RICH <br>preparation. Given the readiness review, we are forced to <br>converge pretty soon on something realistic. The real working<br>considitions will be tested while assembling and may eventually<br>require later adjustments.<br><br>Below we review the discussed arguments and actions, adding few <br>questions we would like to clarify together with DSG.<br><br>--------------------------------------<br>Components<br>--------------------------------------<br>Aerogel: forniture will flow on a regular basis. In EEL-121 clean<br>room we plan to<br>- keep logbook of arrivals <br>- store the aerogel inside the dry cabinets<br>- perform visual inspection<br>- weight the tiles to get the density <--> refractive index<br> --> INFN: the scale DSG proposes is fine with us<br>- (maybe) check dimensions with a mold<br>- (maybe) study optical effects with low-power lasers<br> --> INFN: going to supply information on the lasers we<br> are using in Ferrara, to check which kind of safety<br> regulations they would require at JLab<br>We will organize few trips in Washington to measure the <br>aerogel transmission. We assume italian personnel will do<br>the trip.<br> --> DSG: could be available to help in this task ?<br><br>Spherical Mirrors: 4 mirrors have arrived at Jlab.<br>We are going to open and validate them together with DSG<br>starting the week of 13th of June, while we will be at JLab.<br>We will concentrate in accepting tests, as likely we will not <br>have available all the tools for characterization that week.<br>We plan to<br>- keep logbook<br>- perform visual insepction<br>- perform a pointlike-source spot image measure<br>- (maybe) perform a Shack-Hartmann surface analysis<br>- perform a dimensional check with a CMM machine<br> --> DSG: please check availability of the 60 um CMM<br> machine in the dates 14-17 or 21-22 June.<br><br>Planar mirror: they are being produced, but will be delivered <br>at JLab only after the summer.<br><br>Mechanics: an assembling test will be performed in Italy <br>the first half of June. The RICH module + assembling <br>structure will then be transported at JLab. Except for <br>storing, no action is foreseen at JLab before enough space <br>in EEL-124 will become available (i.e. October).<br><br>Electronics: the JLab FPGA boards should have been produced<br>already. The production of the adapter+Asics boards will<br>start in June. A small quantity will be produced in advance <br>to allow a final check before moving ahead with the massive<br>production (planned in July). In July Matteo Turisini <br>will be at JLab for defining all the procedures and software <br>tools, in collaboration with Ben and DSG, for the electronics <br>acceptance and characterization. The ideal scenario would<br>be DSG will be available to start testing the electronics <br>boards in August. In June Paolo Musico will also visit JLab<br>and work with Ben to the SSP protocol for RICH.<br><br>--------------------------------------<br>Assembling<br>--------------------------------------<br>We plan to perform the RICH assembling in EEL-124 starting<br>not before October 2016.<br><br>Mechanics: we will mount the RICH case inside the assembing<br>structure.<br> --> INFN: has to define the bolt size and lift points.<br><br>Electronics: it can initially be a stand-alone item. With a <br>proper cover of the PMT side, is can run under cosmics and <br>allow for daq, slow control and reconstruction tests. With <br>the back panel in place it will allow for cooling tests.<br>Ideally, we would like to develop/test the same systems we <br>are going to use in the Hall. This means power supplies, <br>cooling system, interlock system, slow control etc...<br> --> INFN: has to discuss with Hall-B management and<br> engineers how to best proceed.<br><br>--------------------------------------<br>Cooling + Interlock<br>--------------------------------------<br>The inlet lines are designed for a typical flux of 100 slm,<br>and a 1 inch size. This flux was tested in a half-size <br>prototype and in a simplified heat load configuration. We<br>would therefore suggest to plan a typical 250 slm with a <br>large safety coefficient (> 50 %).<br> --> DSG: it would be nice to have the presssure<br> sets of the relief valves and the pressure<br> regulators visible in the interlock sketch,<br> as done for the N2 line.<br> --> DSG: should the line from compressor to tank<br> design to sustain the full compressor flux<br> (1200 slm) ?<br> --> DSG: is the current line from tank to RICH<br> suitable for maximum 283 slm (due to the<br> proposed rotameter) ? How complicate is to<br> upgrade it to reach 400 or 600 slm maximum ?<br> --> DSG: The space inside the RICH case is limited:<br> we assume to split the 1 inch tube into few<br> smaller (9-10 mm diameter) plastic tubes for<br> the last part of the line. This may correspond<br> to the ~4m from the patch panel till the electronic<br> panel. Which is the maximum pressure we should<br> aim in this last part of the line ?<br> --> DSG: do we need an interlock for maximum<br> pressure in the tank or in the inlet line or<br> everything is set by the relief valves ?<br> The compressor has its on interlocked limit.<br> --> DSG: the tank you propose is fine with us.<br><br>The interlock logic is relative to the cooling circuit <br>functionality. Other anables for the HV and LV power <br>supplies should come from temperature sensors in few<br>relevant places, i.e. inlet, inner volume, exhaust, FTOF.<br> --> DSG: may you provide information on your<br> board controlling temperature and humidity<br> sensors ? We usually use SHT75 sensors form<br> sensiron<br> --> INFN: should provide detailed information<br> in the compressor and power supply<br> hardware controls.<br><br>--------------------------------------<br>Nitrogen line<br>--------------------------------------<br>We plan to refresh the full RICH volume, close to 5000 <br>liters, in about one day. The current inlet lines are <br>able to provide a maximum of 7200 l/day, with almost a <br>50 % safety factor. We consider it a realistic starting<br>point. We would anyway need to minimize the RICH vessel <br>leaks.<br><br>The LN2 dewar provides a nitrogen with enough purity,<br>with a water content smaller than 0.002%. The filters<br>are just for safety.<br><br>We will need to monitor temperature + humidity with <br>sensors inside the RICH volume.<br><br> --> DSG: do we need an interlock logic for the<br> N2 line, i.e. a shutter to isolate the RICH<br> volume in case of problems ?<br> --> DSG: for example we would be in favor to use<br> humidity sensors to monitor the inlet line<br> quality (the N2 should be fine but we may<br> have leaks or breaks in the line).<br> May we implement those in an cRio interlock<br> logic ?<br> --> DSG: do we need a interlock shutting the N2<br> line in case of over-pressure of the RICH<br> module or relief valves would be enough ?<br> --> DSG: The RICH N2 inner volume is supposed to stay<br> at ~0.5-1 mbar higher pressure than atmospheric,<br> to prevent water flowing in. Is the bubble<br> control system sensible enough to prevent<br> over- or under-pressure ?<br> --> DSG: the N2 line starts with a LN2 dewar:<br> do we need dedicated equipement to prevent<br> moinsture along the line and/or injecting<br> low temperature gas inside the RICH ?<br><br><br>Thank you, Marco.<br>_______________________________________________<br>Clas12_rich mailing list<br>Clas12_rich@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/clas12_rich<br></div><div><br></div><div data-marker="__SIG_POST__">-- <br></div><div>George Jacobs<br>Physics Detector Support Group<br>Jefferson Lab<br>12000 Jefferson Ave.<br>STE 12<br>Newport News, VA 23606<br><br>(office) 757-269-7115<br><br>(cell) 757-876-0480<br><br>(email) jacobsg@jlab.org<br><br>(website) https://userweb.jlab.org/~jacobsg<br></div></div></body></html>