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<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Courier New">Hi,</FONT></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Courier New">From your plots it seems that you need a FEG to reach resolutions beyond about 3 A,</FONT></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Courier New">But I can’t see any great advantage up to about 5 A resolution.</FONT></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Courier New">Is that correct? (and what is all the excitement about then?)</FONT></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Courier New">Philip</FONT></SPAN></P>
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<P ALIGN=LEFT><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma">-----Original Message-----<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT SIZE=2 FACE="Tahoma">From:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma"> Lucken, Uwe [<A HREF="mailto:uwl@nl.feico.com">mailto:uwl@nl.feico.com</A>]<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT SIZE=2 FACE="Tahoma">Sent:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma"> 23 April 2004 15:03<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT SIZE=2 FACE="Tahoma">To:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma"> Philip Koeck; 3dem@ucsd.edu; microscopy@sparc5.microscopy.com<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT SIZE=2 FACE="Tahoma">Cc:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma"> Max.Sidorov@Amd.Com<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT SIZE=2 FACE="Tahoma">Subject:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT SIZE=2 FACE="Tahoma"> RE: Why FEG?</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080" SIZE=2 FACE="Arial">Dear Philip, for an FEG one can set 0.6eV energy spread and for and Lab6 one usually has 1.5eV energy spread. As you can see for –2000nm defocus and 61kx. There is a small mistake in the estimate of the convergence angle. The parallel beam conditions are C2 diameter/7 in microprobe and I have included the plots.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000080" SIZE=2 FACE="Arial"></FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"> </SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">end</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">Sincerely yours,</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">Dr. Uwe Lücken</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">Senior Scientist Application Development</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">FEI-Electron Optics; Building AAE</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="nl"><FONT COLOR="#000080">Achtseweeg Noord; 5600 MD Eindhoven</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="nl"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">The Netherlands</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">tel.:+31-40-2766106; fax:+31-40-2766102</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000080">mob: +31 40 2791621</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<UL><UL>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">-----Original Message-----<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">From:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma"> Philip Koeck [<A HREF="mailto:Philip.Koeck@biosci.ki.se">mailto:Philip.Koeck@biosci.ki.se</A>]<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">Sent:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma"> Friday, April 23, 2004 10:44 AM<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">To:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma"> 3dem@ucsd.edu; microscopy@sparc5.microscopy.com<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">Cc:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma"> Max.Sidorov@Amd.Com; Lucken, Uwe<BR>
</FONT></SPAN><SPAN LANG="en-us"><B></B></SPAN><SPAN LANG="en-us"><B><FONT COLOR="#000000" SIZE=2 FACE="Tahoma">Subject:</FONT></B></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Tahoma"> Why FEG?</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="sv"><FONT COLOR="#000000" SIZE=2 FACE="Arial">Hi,</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="sv"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="sv"><FONT COLOR="#000000" SIZE=2 FACE="Arial"> </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="sv"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">I’ve been playing around with Max Sidorow's CTFexplorer and I’m finding it hard to see the<BR>
advantage of FEG microscopes for structural biology.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">At 61000-times magnification I can’t see any major difference between the Tecnai 20T and<BR>
the Tecnai F20T for example.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">Only at magnifications beyond 300000 is the F20T clearly superior (due to better spatial<BR>
coherence).</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial"> </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">Am I (or is CTFexplorer) missing something relevant?</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial"> </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">The CTFexplorer can be found at</FONT></SPAN><SPAN LANG="en-us"> </SPAN><A HREF="http://clik.to/ctfexplorer"><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><U><FONT COLOR="#0000FF" SIZE=2 FACE="Arial">http://clik.to/ctfexplorer</FONT></U></SPAN><SPAN LANG="en-us"></SPAN></A><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">Upon request I can also send a Word file with the CTF-plots.</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial"> </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial">Philip</FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P ALIGN=LEFT><SPAN LANG="en-us"><FONT COLOR="#000000" SIZE=2 FACE="Arial"> </FONT></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
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