<html><body><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000"><div>Will do.<br></div><div>1.05mm ID (.041 inches) +/- 0.05mm</div><div><br></div><div data-marker="__SIG_PRE__">Tim Whitlatch<br>Hall D Engineer<br>Jefferson Lab<br>600 KELVIN DR STE 5<br>Newport News, VA 23606-4468 <br>757-269-5087</div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>From: </b>"Richard Jones" <richard.t.jones@uconn.edu><br><b>To: </b>"Timothy Whitlatch" <whitey@jlab.org><br><b>Cc: </b>"Alexandre Deur" <deurpam@jlab.org>, "Hall-D Tagged Beam Group" <halld-tagger@jlab.org>, "Egiyan, Hovanes" <hovanes@jlab.org><br><b>Sent: </b>Thursday, January 21, 2016 3:16:26 PM<br><b>Subject: </b>Re: [Halld-tagger] Tungsten tube in primary collimator<br></div><div><br></div><div data-marker="__QUOTED_TEXT__"><div dir="ltr">Tim and all,<br><div>As far as I am concerned, the design you propose does the job. Being only 7.5 cm long also helps because being shorter makes the pointing of the axis back at the radiator spot less critical. I would say to go for it. The only change I would request is to reduce the diameter from 1.5mm to the range 1.0-1.1 mm, whatever works best for people who prefer English (actually American) units.</div><br><div>-Richard Jones</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jan 21, 2016 at 3:00 PM, Timothy Whitlatch <span dir="ltr"><<a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div style="font-family:arial,helvetica,sans-serif;font-size:12pt;color:#000000"><div>Alexandre,<br></div><br><div>Thanks for trying to simplify (and lower the cost of) the pieces.<br></div><div>The gap would not be the same all around <br></div><div>The gap would only be on the top and bottom (or sides only). This may make it hard to center.<br></div><br><div>The cost is about $1K for the custom pieces.<br></div><br><div>I think we just do the 2 custom pieces, therefore we will know exactly what we have.<br></div><br><div>Timeframe is about 2 weeks.<br></div><br><div>Is it a go?<br></div><span class=""><br><br><div>Tim Whitlatch<br>Hall D Engineer<br>Jefferson Lab<br>600 KELVIN DR STE 5<br>Newport News, VA 23606-4468 <br><a href="tel:757-269-5087" target="_blank">757-269-5087</a><br data-mce-bogus="1"></div><br></span><hr><div><b>From: </b>"Alexandre Deur" <<a href="mailto:deurpam@jlab.org" target="_blank">deurpam@jlab.org</a>><br><b>To: </b>"Timothy Whitlatch" <<a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a>><br><b>Cc: </b>"Curtis A. Meyer" <<a href="mailto:cmeyer@cmu.edu" target="_blank">cmeyer@cmu.edu</a>>, "Hall-D Tagged Beam Group" <<a href="mailto:halld-tagger@jlab.org" target="_blank">halld-tagger@jlab.org</a>>, "Hovanes Egiyan" <<a href="mailto:hovanes@jlab.org" target="_blank">hovanes@jlab.org</a>><br><b>Sent: </b>Thursday, January 21, 2016 2:00:34 PM<div><div class="h5"><br><b>Subject: </b>Re: [Halld-tagger] Tungsten tube in primary collimator<br></div></div></div><div><div class="h5"><br><div>If we wrap the tube in aluminum tape, the gap will be 100 um everywhere and filled with aluminum. It might be an acceptable and faster solution than machining custom pieces? <br><br>Alexandre<br><br>----- Original Message -----<br>> From: "Timothy Whitlatch" <<a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a>><br>> To: "Curtis A. Meyer" <<a href="mailto:cmeyer@cmu.edu" target="_blank">cmeyer@cmu.edu</a>><br>> Cc: "Hall D beam working group" <<a href="mailto:halld-tagger@jlab.org" target="_blank">halld-tagger@jlab.org</a>>, "Hovanes Egiyan" <<a href="mailto:hovanes@jlab.org" target="_blank">hovanes@jlab.org</a>><br>> Sent: Thursday, January 21, 2016 1:07:37 PM<br>> Subject: Re: [Halld-tagger] Tungsten tube in primary collimator<br><br>> Yes, off the diameter. It would leave a 200um gap at top.<br>> <br>> We can overcome this by making 2 custom pieces, so not a big deal.<br>> <br>> <br>> Tim Whitlatch<br>> Hall D Engineer<br>> Jefferson Lab<br>> 600 KELVIN DR STE 5<br>> Newport News, VA 23606-4468<br>> <a href="tel:757-269-5087" target="_blank">757-269-5087</a><br>> <br>> <br>> From: "Curtis A. Meyer" <<a href="mailto:cmeyer@cmu.edu" target="_blank">cmeyer@cmu.edu</a>><br>> To: "Richard Jones" <<a href="mailto:richard.t.jones@uconn.edu" target="_blank">richard.t.jones@uconn.edu</a>><br>> Cc: "Timothy Whitlatch" <<a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a>>, "Hall-D Tagged Beam Group"<br>> <<a href="mailto:halld-tagger@jlab.org" target="_blank">halld-tagger@jlab.org</a>>, "Egiyan, Hovanes" <<a href="mailto:hovanes@jlab.org" target="_blank">hovanes@jlab.org</a>><br>> Sent: Thursday, January 21, 2016 12:25:56 PM<br>> Subject: Re: [Halld-tagger] Tungsten tube in primary collimator<br>> <br>> I think it comes of a diamater, not the length. That leaves a small “crack”<br>> along the top??<br>> -------<br>> Prof. Curtis A. Meyer Department of Physics<br>> Phone: <a href="tel:%28412%29%20268-2745" target="_blank">(412) 268-2745</a> Carnegie Mellon University<br>> Fax: <a href="tel:%28412%29%20681-0648" target="_blank">(412) 681-0648</a> Pittsburgh, PA 15213<br>> <a href="mailto:curtis.meyer@cmu.edu" target="_blank">curtis.meyer@cmu.edu</a> <a href="http://www.curtismeyer.com/" target="_blank">http://www.curtismeyer.com/</a><br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> <br>> On Jan 21, 2016, at 11:37 AM, Richard Jones < <a href="mailto:richard.t.jones@uconn.edu" target="_blank">richard.t.jones@uconn.edu</a> > wrote:<br>> <br>> Tim,<br>> <br>> I wasn't sure which dimension the 200 microns comes off of, but if it is the<br>> length (7.5cm) there is no need to fine-adjust that, 7.4 cm would work just as<br>> well.<br>> <br>> -Richard J.<br>> <br>> On Thu, Jan 21, 2016 at 11:08 AM, Timothy Whitlatch < <a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a> > wrote:<br>> <br>> <br>> <br>> Hi All,<br>> <br>> I can get 5mm diameter precision ground tungsten carbide rod (twice the density<br>> of steel) 7.5cm long.<br>> <br>> This can be cut in half lengthwise and then the aperture cut in each half.<br>> <br>> With the wire EDM machining process we will loose about 200um but can overcome<br>> this by making additional pieces and matching them together.<br>> <br>> Tim Whitlatch<br>> Hall D Engineer<br>> Jefferson Lab<br>> 600 KELVIN DR STE 5<br>> Newport News, VA 23606-4468<br>> <a href="tel:757-269-5087" target="_blank">757-269-5087</a><br>> <br>> <br>> From: "Richard Jones" < <a href="mailto:richard.t.jones@uconn.edu" target="_blank">richard.t.jones@uconn.edu</a> ><br>> To: "Timothy Whitlatch" < <a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a> ><br>> Cc: "Alexandre Deur" < <a href="mailto:deurpam@jlab.org" target="_blank">deurpam@jlab.org</a> >, "Eugene Chudakov" < <a href="mailto:gen@jlab.org" target="_blank">gen@jlab.org</a> >,<br>> "Hall-D Tagged Beam Group" < <a href="mailto:halld-tagger@jlab.org" target="_blank">halld-tagger@jlab.org</a> ><br>> Sent: Thursday, January 21, 2016 9:19:31 AM<br>> Subject: Re: Tungsten tube in primary collimator<br>> <br>> Dear colleagues,<br>> Yesterday I promised to do a quick MC study to determine what a steel collimator<br>> insert with an aperture adjusted to allow the TAC to run safely with a 10 nA<br>> electron beam and a 2e-5 radlen radiator. The answers are given in a quick tech<br>> note that I link below. I am not done writing it yet, so if there are plots or<br>> results that you would like to see added please let me know. The bottom line is<br>> that steel will work just fine, and it only needs to be 15 cm long. The inner<br>> aperture diameter should be 1.1 mm. In response to Tim's question, tungsten<br>> would be better of course, but steel seems to work just fine and might be<br>> easier to work with.<br>> <br>> <a href="http://zeus.phys.uconn.edu/halld/collim-1-2016/collim-1-2016.pdf" target="_blank">http://zeus.phys.uconn.edu/halld/collim-1-2016/collim-1-2016.pdf</a><br>> <br>> -Richard Jones<br>> <br>> On Thu, Jan 21, 2016 at 7:55 AM, Timothy Whitlatch < <a href="mailto:whitey@jlab.org" target="_blank">whitey@jlab.org</a> > wrote:<br>> <br>> <br>> <br>> Hi All,<br>> <br>> In speaking with the machine shop, we can take a precision ground tungsten rod<br>> and cut it in half long wise with wire EDM.<br>> We can then cut a 1.5mm diameter half hole in each half.<br>> <br>> Both halves would then be put in the 5mm primary collimator hole together giving<br>> us a 1.5mm hole (or what diameter is needed).<br>> <br>> Tim Whitlatch<br>> Hall D Engineer<br>> Jefferson Lab<br>> 600 KELVIN DR STE 5<br>> Newport News, VA 23606-4468<br>> <a href="tel:757-269-5087" target="_blank">757-269-5087</a><br>> <br>> <br>> _______________________________________________<br>> Halld-tagger mailing list<br>> <a href="mailto:Halld-tagger@jlab.org" target="_blank">Halld-tagger@jlab.org</a><br>> <a href="https://mailman.jlab.org/mailman/listinfo/halld-tagger" target="_blank">https://mailman.jlab.org/mailman/listinfo/halld-tagger</a><br>> <br>> <br>> <br>> _______________________________________________<br>> Halld-tagger mailing list<br>> <a href="mailto:Halld-tagger@jlab.org" target="_blank">Halld-tagger@jlab.org</a><br>> <a href="https://mailman.jlab.org/mailman/listinfo/halld-tagger" target="_blank">https://mailman.jlab.org/mailman/listinfo/halld-tagger</a><br></div></div></div></div></div><br>_______________________________________________<br>
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