<html><body><div style="font-family: tahoma,new york,times,serif; font-size: 14pt; color: #009900"><div>george,<br></div><div>amanda et.al are right.<br data-mce-bogus="1"></div><div>thanks for the prompt response guys, the young and the restless!<span id="transmark" style="display: none; width: 0px; height: 0px;"></span><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>however, i believe, we should follow the ALARA principle.</div><div><br></div><div>we should shoot for less than 3ppm water molecules, this should take ~ 24 hrs.<br data-mce-bogus="1"></div><div>3ppm in 5 m^3 is ~4*10^20.<br data-mce-bogus="1"></div><div>also,we should over pressure the N2 volume adequately so there is no incoming water molecules, so that it is not subject to ambient pressure changes. <br data-mce-bogus="1"></div><div><br data-mce-bogus="1"></div><div>we'll discuss these matters in the dsg meeting<br data-mce-bogus="1"></div><div><br></div><div><br data-mce-bogus="1"></div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Amanda Hoebel" <amandah@jlab.org><br><b>To: </b>dsg-rich@jlab.org<br><b>Sent: </b>Monday, October 9, 2017 4:00:29 PM<br><b>Subject: </b>Re: [Dsg-rich] RICH installation activity<br></div><div><br></div><div data-marker="__QUOTED_TEXT__">Hi George,<br><br>Tyler, Pablo, and I were looking at the calculation of humidity decrease and found that if the total exchange rate for both RICH channels is 40 slm and the volume of the RICH is 5000 L then, using the exponential decay calculation, the time to go from 50% humidity to 1% humidity is about 8 hours.<br><br>Regards,<br>Amanda<br><br>----- Original Message -----<br>From: "George Jacobs" <jacobsg@jlab.org><br>To: "Marco Mirazita" <Marco.Mirazita@lnf.infn.it>, dsg-rich@jlab.org, rich@jlab.org<br>Sent: Monday, October 9, 2017 11:18:32 AM<br>Subject: Re: [Dsg-rich] RICH installation activity<br><br>I have some questions and comments concerning how fast you want to "fill" the RICH, <br><br>Questions first; <br><br>#1 What is the time frame you require for purging the RICH volume from initial condition of clean room air, ~ 50% humidity, to your final desired number? <br><br>#2 What is the maximum final H2O concentration for storage and operation? <br><br>#3 What is the N2 volume of the detector? <br><br>Comments; <br><br>N2 gas purge supply details; <br>- The N2 purge supply flow is controlled by a mechanical valve rotometer, 0-20 slm <br>- Purge flow is monitored by a mass flow transducer, 0-20 slm <br>- The N2 purge supply valve panel is a pressure system <br><br>N2 purge supply flow specifications <br>Channel 1 maximum flow - 20 slm (1200 liters per hour/28,800 liters per day) <br>Channel 2 maximum flow - 20 slm (1200 liters per hour/28,800 liters per day) <br><br>The above maximum flow specifications remain constant with regard to the type or source of the N2 supply. <br><br>Thanks, <br>George <br><br>On 10/9/2017 10:19 AM, Marco Mirazita wrote: <br><br><br><br><br>- Nitrogen <br>1) Setup the N2 distribution lines inside the RICH. <br>2) The dewar is not suitable to fill the RICH quickly (i.e. in few hours). A new system must be used, for example bottles. This should be discussed timely with the DSG. There is the plan to test the N2 system in the RICH for the week of October 16. This test will include installation of the exit panel, rotation of the RICH in vertical position, installation of the frontal panels (possibly using the assembly frame), sealing of the electronic panel region with plastic. It makes sense to do all this assembly work only if we have (or we may have) a way to fill the RICH with N2 in a reasonable time. <br><br><br><br><br>_______________________________________________ <br>Dsg-rich mailing list <br>Dsg-rich@jlab.org <br>https://mailman.jlab.org/mailman/listinfo/dsg-rich <br><br>-- <br>George Jacobs<br>Jefferson Lab (TJNAF)<br>STE 12<br>12000 Jefferson Ave.<br>Newport News, VA 23606<br><br>(office) 757-269-7115<br><br>(cell) 757-876-0480<br><br>(email) jacobsg@jlab.org (website) https://userweb.jlab.org/~jacobsg <br><br>_______________________________________________<br>Dsg-rich mailing list<br>Dsg-rich@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-rich<br>_______________________________________________<br>Dsg-rich mailing list<br>Dsg-rich@jlab.org<br>https://mailman.jlab.org/mailman/listinfo/dsg-rich<br></div></div></body></html>