[Halld-tagger] Tungsten tube in primary collimator

[Richard Jones]

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
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/halld-tagger/attachments/20160121/1be65e9f/attachment.html>