[Imgcif-l] ... also

[harry powell]

Hi

Yes, it makes sense to have the definition of the size at the edge of  
the slits nearest the crystal and the divergence (or cross-fire,  
whatever you want to call it), since it should be simple arithmetic  
(for a simple beam) to work out from that the size of the beam at the  
crystal and the detector.

On 16 Feb 2010, at 23:13, James Hester wrote:

> I agree with Herbert's suggestion, although I would name the tags
>
> _diffrn_radiation.beam_size_x
> _diffrn_radiation.beam_size_y
>
> simply because that makes more immediate sense to me. 'Spread'  
> reminds me of
> 'wavelength spread', 'angular spread', 'vegemite' etc. But that  
> might just
> be me.
>
> I would advocate against the use of a slit width unless enough  
> information
> is provided to interpret its meaning i.e. location of the slit  
> relative to
> source/monochromator/sample/other slits.
>
> NB The powder CIF dictionary defines beam size tags for the size of  
> the beam
> at the sample (DDL1, however).
>
> James.
>
> On Wed, Feb 17, 2010 at 12:05 AM, Herbert J. Bernstein <
> yaya at bernstein-plus-sons.com> wrote:
>
>> Another nice question.  We have the angular crossfire in
>>
>> _diffrn_radiation.div_x_source
>> _diffrn_radiation.div_y_source
>> _diffrn_radiation.div_x_y_source
>>
>> Should this new tag be viewed as a characteristic of the beam,
>> say
>>
>> _diffrn_radiation.spread_x_source
>> _diffrn_radiation.spread_y_source
>> _diffrn_radiation.spread_x_y_source
>>
>> or, as Graeme suggests, the width of slits collimating the beam
>> or as ???
>>
>> Suggestions, please.
>>
>> =====================================================
>>  Herbert J. Bernstein, Professor of Computer Science
>>    Dowling College, Kramer Science Center, KSC 121
>>         Idle Hour Blvd, Oakdale, NY, 11769
>>
>>                  +1-631-244-3035
>>                  yaya at dowling.edu
>> =====================================================
>>
>> On Tue, 16 Feb 2010, Graeme.Winter at Diamond.ac.uk wrote:
>>
>>> Hello again,
>>>
>>> Is there a way to specify the size of the beam - or at least, the  
>>> gap
>>> between the slits? This obviously relates to the question before.
>>>
>>> Looking in the dictionary from version 1.5.4 - 2007-07-28 I could  
>>> not
>>> find these (this was the latest dictionary I could find in the  
>>> cbflib
>>> distribution)
>>>
>>> Thanks again,
>>>
>>> Graeme
>>>
>>> Graeme Winter
>>> Software and MX Support Scientist
>>> Diamond Light Source
>>>
>>> +44 1235 778091 (work)
>>> +44 7786 662784 (work mobile)
>>>
>>>
>>>
>>>
>>>
>>> --
>>>
>>> This e-mail and any attachments may contain confidential,  
>>> copyright and
>> or privileged material, and are for the use of the intended  
>> addressee only.
>> If you are not the intended addressee or an authorised recipient  
>> of the
>> addressee please notify us of receipt by returning the e-mail and  
>> do not
>> use, copy, retain, distribute or disclose the information in or  
>> attached to
>> the e-mail.
>>>
>>> Any opinions expressed within this e-mail are those of the  
>>> individual and
>> not necessarily of Diamond Light Source Ltd.
>>>
>>> Diamond Light Source Ltd. cannot guarantee that this e-mail or any
>> attachments are free from viruses and we cannot accept liability  
>> for any
>> damage which you may sustain as a result of software viruses which  
>> may be
>> transmitted in or with the message.
>>>
>>> Diamond Light Source Limited (company no. 4375679). Registered in  
>>> England
>> and Wales with its registered office at Diamond House, Harwell  
>> Science and
>> Innovation Campus, Didcot, Oxfordshire, OX11 0DE, United Kingdom
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> imgcif-l mailing list
>>> imgcif-l at iucr.org
>>> http://scripts.iucr.org/mailman/listinfo/imgcif-l
>>>
>> _______________________________________________
>> imgcif-l mailing list
>> imgcif-l at iucr.org
>> http://scripts.iucr.org/mailman/listinfo/imgcif-l
>>
>
>
>
> -- 
> T +61 (02) 9717 9907
> F +61 (02) 9717 3145
> M +61 (04) 0249 4148
> _______________________________________________
> imgcif-l mailing list
> imgcif-l at iucr.org
> http://scripts.iucr.org/mailman/listinfo/imgcif-l

Harry
--
Dr Harry Powell, MRC Laboratory of Molecular Biology, MRC Centre, Hills
Road, Cambridge, CB2 0QH