Re: [ATM] Ronchi quiz

["Jerry" <wa4guu@verizon.net>]

Seriously this time... This looks like it would the ultra-thin 3/16 or so
inch mirror.  And if so it shows some interesting defects that I would say
look likely to be caused by factors that will be very hard to overcome.

I'm guessing that small irregularities in thickness and perhaps irregular
strain are causing the surface to ripple when polishing. 

It may be that as well a uniform support it may need a uniform heat sink to
dissipate polishing heat away in a way that prevents small differences in
thickness or glass quality from having a large effect due to acting on such
a small thickness.

Jerry 

-----Original Message-----
From: Dale Eason [mailto:atmpob@yahoo.com] 
Sent: Tuesday, January 31, 2006 11:13 PM
To: atm@atmlist.net
Subject: [ATM] Ronchi quiz


I thought ronchi users might like to take a stab at
the this image.  It is from a 16 inch mirror in
progress. It is pollished out.  Can any tell me what
they think is going on?  I know and will tell you in a
few days.  I wonder if anyone has ever seen anything
like it.  The position of the ronchi screen is very
close to the ROC.

http://home.comcast.net/~doeason/DDavis/ronchi.jpg

A clue is in the file name.  One other on the list
might recognize the image.

Next is a Foucault image taken at the same ROC.  It
may help you to interpret the image.  The main purpose
of the foucault image is to show that it is a mirror
eventhough it has many faults.

http://home.comcast.net/~doeason/DDavis/foucault1.jpg


Dale Eason





__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
_______________________________________________
ATM mailing list http://www.atmlist.net/

_______________________________________________
ATM mailing list http://www.atmlist.net/