[Halld-tagger] Tungsten tube in primary collimator

[Alexandre Deur]

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? 

Alexandre

----- Original Message -----
> From: "Timothy Whitlatch" <whitey at jlab.org>
> To: "Curtis A. Meyer" <cmeyer at cmu.edu>
> Cc: "Hall D beam working group" <halld-tagger at jlab.org>, "Hovanes Egiyan" <hovanes at jlab.org>
> Sent: Thursday, January 21, 2016 1:07:37 PM
> Subject: Re: [Halld-tagger] Tungsten tube in primary collimator

> Yes, off the diameter. It would leave a 200um gap at top.
> 
> We can overcome this by making 2 custom pieces, so not a big deal.
> 
> 
> Tim Whitlatch
> Hall D Engineer
> Jefferson Lab
> 600 KELVIN DR STE 5
> Newport News, VA 23606-4468
> 757-269-5087
> 
> 
> From: "Curtis A. Meyer" <cmeyer at cmu.edu>
> To: "Richard Jones" <richard.t.jones at uconn.edu>
> Cc: "Timothy Whitlatch" <whitey at jlab.org>, "Hall-D Tagged Beam Group"
> <halld-tagger at jlab.org>, "Egiyan, Hovanes" <hovanes at jlab.org>
> Sent: Thursday, January 21, 2016 12:25:56 PM
> Subject: Re: [Halld-tagger] Tungsten tube in primary collimator
> 
> I think it comes of a diamater, not the length. That leaves a small “crack”
> along the top??
> -------
> Prof. Curtis A. Meyer Department of Physics
> Phone: (412) 268-2745 Carnegie Mellon University
> Fax: (412) 681-0648 Pittsburgh, PA 15213
> curtis.meyer at cmu.edu http://www.curtismeyer.com/
> 
> 
> 
> 
> 
> 
> 
> 
> On Jan 21, 2016, at 11:37 AM, Richard Jones < richard.t.jones at uconn.edu > wrote:
> 
> Tim,
> 
> I wasn't sure which dimension the 200 microns comes off of, but if it is the
> length (7.5cm) there is no need to fine-adjust that, 7.4 cm would work just as
> well.
> 
> -Richard J.
> 
> On Thu, Jan 21, 2016 at 11:08 AM, Timothy Whitlatch < whitey at jlab.org > wrote:
> 
> 
> 
> Hi All,
> 
> I can get 5mm diameter precision ground tungsten carbide rod (twice the density
> of steel) 7.5cm long.
> 
> This can be cut in half lengthwise and then the aperture cut in each half.
> 
> With the wire EDM machining process we will loose about 200um but can overcome
> this by making additional pieces and matching them together.
> 
> Tim Whitlatch
> Hall D Engineer
> Jefferson Lab
> 600 KELVIN DR STE 5
> Newport News, VA 23606-4468
> 757-269-5087
> 
> 
> From: "Richard Jones" < richard.t.jones at uconn.edu >
> To: "Timothy Whitlatch" < whitey at jlab.org >
> Cc: "Alexandre Deur" < deurpam at jlab.org >, "Eugene Chudakov" < gen at jlab.org >,
> "Hall-D Tagged Beam Group" < halld-tagger at jlab.org >
> Sent: Thursday, January 21, 2016 9:19:31 AM
> Subject: Re: Tungsten tube in primary collimator
> 
> Dear colleagues,
> Yesterday I promised to do a quick MC study to determine what a steel collimator
> insert with an aperture adjusted to allow the TAC to run safely with a 10 nA
> electron beam and a 2e-5 radlen radiator. The answers are given in a quick tech
> note that I link below. I am not done writing it yet, so if there are plots or
> results that you would like to see added please let me know. The bottom line is
> that steel will work just fine, and it only needs to be 15 cm long. The inner
> aperture diameter should be 1.1 mm. In response to Tim's question, tungsten
> would be better of course, but steel seems to work just fine and might be
> easier to work with.
> 
> http://zeus.phys.uconn.edu/halld/collim-1-2016/collim-1-2016.pdf
> 
> -Richard Jones
> 
> On Thu, Jan 21, 2016 at 7:55 AM, Timothy Whitlatch < whitey at jlab.org > wrote:
> 
> 
> 
> Hi All,
> 
> In speaking with the machine shop, we can take a precision ground tungsten rod
> and cut it in half long wise with wire EDM.
> We can then cut a 1.5mm diameter half hole in each half.
> 
> Both halves would then be put in the 5mm primary collimator hole together giving
> us a 1.5mm hole (or what diameter is needed).
> 
> Tim Whitlatch
> Hall D Engineer
> Jefferson Lab
> 600 KELVIN DR STE 5
> Newport News, VA 23606-4468
> 757-269-5087
> 
> 
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