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<p class="MsoNormal">Sean,<o:p></o:p></p>
<p class="MsoNormal"> I am not entirely sure, but it’s not likely that the gases will completely disassociate from each other, even if the pressure drops. I’m assuming that because the vapor pressure of BCL3 is a constant because it is a liquid, you are determining
that mostly Ar is being consumed because of the pressure drop. I would recommend a complete pump and purge of the entire gas circuit and replacing the cylinder of BCL3.<o:p></o:p></p>
<p class="MsoNormal">The simplest way to evaluate the gas concentrations is with an RGA but I don’t think it’s a good idea to expose the filament to a corrosive such as BCL3<o:p></o:p></p>
<p class="MsoNormal"> Steve “Equipment Dood” Paolini<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:14.0pt">Steve Paolini<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Principal Equipment Engineer<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Harvard University Center for Nanoscale Systems<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">11 Oxford St.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Cambridge, MA 02138<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">617- 496- 9816<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">spaolini@cns.fas.harvard.edu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">www.cns.fas.harvard.edu</span><span style="font-size:14.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> labnetwork-bounces@mtl.mit.edu <labnetwork-bounces@mtl.mit.edu>
<b>On Behalf Of </b>Rinehart, Sean<br>
<b>Sent:</b> Wednesday, June 19, 2019 1:15 PM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Argon in a BCl3 cylinder<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hello all,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Recently our facility’s BCl3 cylinder had been charged with argon, increasing the delivery pressure to 25 psi. The cause has been corrected, but now I’m evaluating whether or not the cylinder needs to be replaced, and would appreciate some
advice.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Since the root issue was fixed, the pressure has slowly dropped from 25 psi to 15 psi with use. Based on this, it seems like with more use the argon should completely deplete from the cylinder, but maybe someone can tell me if that’s actually
true, and if there’s a way to evaluate gas concentrations. Additionally, the plasma glow is whitish instead of pink, so there’s definitely BCl3 content in the delivered gas.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sean Rinehart<o:p></o:p></p>
<p class="MsoNormal">Assistant Director, Cleanroom Operations<o:p></o:p></p>
<p class="MsoNormal">Yale University<o:p></o:p></p>
<p class="MsoNormal">203 432 4303 <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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