[RASMB] Looking for help with the XL-A optics

[Borries Demeler]

Dear Osman,

I agree that the radial intensity variation is much greater than it should
be. Also, the maximum emission intensity should be at 230 nm (+/- 1-2 nm).

There are a couple of issues you should look at:

1. I would ask Beckman to send you a different monochromator that has been
verified to work well in a different instrument. There may be a flaw with yours
that causes the wrong wavelength to be set.

2. check other components in your optical path that may be obstructing
the light path. They include the slit assembly. Be very careful when you
clean the slit not to damage the film. Also clean the lens in the slit assembly.

You should be able to get this to work by yourself, but let me know if you
need help with instructions to clean the slit assembly. We can probably
guide you over skype how to do this.

Regards, -borries

> 
> Dear RASMB subscribers,
> 
> We recently noticed that the intensity scans taken by our XL-A show extreme
> radial dependence. Furthermore, we discovered that our lamp was exhibiting
> intensity peaks significantly shifted from their supposed wavelengths.
> 
> Below are radial scans taken for empty holes and the counterbalance, and
> also a wavelength-intensity scan taken at 6.5 cm:
> 
> http://dl.dropbox.com/u/10119274/reanalyticalultracentrifugexla.zip
> 
> 
> We tried cleaning the lamp and adjusting its alignment, but that did not
> help.
> 
> We are located in Saudi Arabia, and the local distributor does not have the
> expertise to deal with an AUC. We contacted Beckman in Europe for help, but
> they are being much slower in their response  than I had hoped.  Having the
> AUC up and running again is of critical importance to the users at my
> university (KAUST), since it is currently the only AUC in Saudi Arabia.
> Therefore, the university's priority is to get it fixed in the shortest
> time frame possible.
> 
> If you or someone you know can resolve this problem, we'll be more than
> happy to: a) pay a consulting fee (if the problem can be resolved by
> remotely directing us); or b) pay for a round trip plane ticket, plus
> lodging and a consulting fee, if the problem can only be resolved by
> on-site service.
> 
> 
> Please send your inquiries or suggestions directly to me at
> osman.bakr at kaust.edu.sa
> 
> 
> 
> Regards.
> 
> 
> -Osman
> 
> 
> 
> 
> 
> 
> 
> -- 
> Osman Bakr
> Assistant Professor
> Materials Science and Engineering
> King Abdullah University of Science and Technology (KAUST)
> Building 3, Room # 3236
> Thuwal 23955-6900
> Saudi Arabia
> Tel: +96628084439
> http://www.kaust.edu.sa/academics/faculty/bakr.html<http://www.kaust.edu.sa/academics/faculty/bakr.html>
>