Oval is always a problem without looking


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Stephen Brooks <sbrooks@bnl.gov> wrote:


Can you find what thickness I need for a fully circular pipe with 24.4mm 
inner radius?  So I can see if the oval shape is causing problems.

    -Stephen


-----Original Message----- 
From: Mapes, Michael D
Sent: 2015 July 28; Tuesday 16:17
To: Brooks, Stephen
Subject: Re: Cbeta vacuum chamber


4mm

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Stephen Brooks <sbrooks@bnl.gov> wrote:


Is that for 3mm thickness?

-----Original Message----- 
From: Mapes, Michael D
Sent: 2015 July 28; Tuesday 16:11
To: Brooks, Stephen
Cc: Bruce Dunham ; Witte, Holger ; Trbojevic, Dejan
Subject: Re: Cbeta vacuum chamber


Increasing the height from 8 to 10 mm just gets an FS of 2
Regards,
Mike

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Stephen Brooks <sbrooks@bnl.gov> wrote:


The chamber will be quite long in the Z direction (over a metre in current
plans).

What would affect the thickness?  Would it be better if the chamber height
was increased so it becomes more circular?

    -Stephen


-----Original Message----- 
From: Mapes, Michael D
Sent: 2015 July 28; Tuesday 10:42
To: Brooks, Stephen
Cc: Bruce Dunham ; Witte, Holger ; Trbojevic, Dejan
Subject: Re: Cbeta vacuum chamber


Stephen,
I assumed long chamber but even with 4mm thickness the FS is only 1.93  we
usually like 2 as a minimum.
Regards,
Mike

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Stephen Brooks <sbrooks@bnl.gov> wrote:


Here's how the dimensions I mentioned fit onto that picture.

-----Original Message----- 
From: Stephen Brooks
Sent: 2015 July 23; Thursday 11:52
To: Michael D Mapes
Cc: Bruce Dunham ; Holger Witte ; Dejan Trbojevic
Subject: Cbeta vacuum chamber

Hi Mike,

We're trying to work out the size and thickness needed for the vacuum
chamber of the eRHIC prototype machine (Cbeta) at Cornell.  The attached
picture (grey ovals) shows the general shape I've been considering, but the
3mm Aluminium thickness was a guess.

What we actually need (at least in the design shown in the picture) is:

Beam centre of furthest beam is at X=18.4mm plus 6mm of clearance, so 24.4mm
inner half-width.

The ends are circles dictated by the 6mm clearance radius, while the inner
half-height I set at Y=8mm.  I added a circular arc to join this together.

I'd be interested to know whether you think this is a practical shape and/or
what thickness of metal you would suggest we use, or suggestions for other
ways of constructing the oval.  Using a pure ellipse I found the ends got a
bit narrow.

    -Stephen