Shay,

Can we assume you are working with a reflection mode instrument?

You have two primary sources of background - the primary beam hitting the 
detector directly, and x-rays scattering from the air rather than the sample.

The first of these you control with the divergence slits, but really shouldn't 
be a problem until you go below 4-5 degrees. If you do scan from those sorts of 
angles, set the divergence slits to ~0.1 degrees to keep the beam on the 
sample. I haven't tested it myself, but you could also try reducing the 
detection window on the LynxEye if you want to go to really low angles (<2 
degrees).

The air scatter can be reduced with a special screen/knife that you should have 
received with the instrument, and correctly aligned it will reduce a lot of the 
background increase you see below 10-15 degrees 2-theta. There should be some 
instructions in the instrument manual about this. Using a smaller divergence 
slit (and a receiving slit if you have the option) will also reduce the 
background from airscatter.

I don't think that lowering the tube power will help very much,


jools







________________________________
From: rietveld_l-requ...@ill.fr [rietveld_l-requ...@ill.fr] on behalf of Shay 
Tirosh [stiro...@gmail.com]
Sent: 06 March 2016 10:51
To: rietveld_l@ill.fr
Subject: Aking for Advice - reduce the current to X-ray tube to avoid director 
saturation at low angels

Dear Rietvelders

I would like to avoid director saturation (we have a LYNXEYE detector) when I 
work at low angles (lower then 10deg).
I thought it would be good to lower the current tube to reduce the current. say 
to 35mA instead of 40mA.
Can you please comment on problems it should encounter?
Can I correct problems by slowing down my scanning time?

Thank you from advance
Shay

--
_________________________________________________

Dr. Shay Tirosh
Institute for Nanotechnology & Advanced Materials
Bar Ilan University
Ramat Gan, 52900
Israel
Phone: +972-(0)30-531-7320
Mobile: +972-(0)54-8834533
Email: stiro...@gmail.com<mailto:stiro...@gmail.com>
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