Responsive beam time webinar 2020

Are there opportunities for covid-19 related research at XFEL facilities?

The XFEL Hub at Diamond has been granted some beamtime for Covid-19 projects at:

• LCLS - MFX -- Rapid Access beamtime is planned to start in mid Aug  (P175 Orville et al; LCLS-MFX, 18-21 Sep 2020 )
• PAL-XFEL -- we have room for a few samples with beamtime planned for 16-20 Aug and 20-25 Oct 2020
• The European XFEL has an open call for rapid access proposals at the SPB/SFX instrument

https://www.xfel.eu/organization/covid19/index_eng.html

For more information please e-mail ([email protected])

What is Diamond's preferred length of a remote access shift during these measures?

There is no preferred length of shift. We are allocating time based on the number of samples and requested shift length (as filled in ISPyB on shipping of samples). Within a group, or block allocation group (BAG) please monitor your usage, as we cannot guarantee beamtime later in the run. If we become over subscribed we may need to base time allocated on the relative amount of time awarded in AP27.

Registration for new sample holders

• We have new unipucks/containers that have not been registered yet at Diamond.
• Will we need to send them for registration/etching prior to using them for the first sample shipment?
• If not, how can we fill in samples in ISPyB prior to shipment and registration of pucks/containers?

Normally with a full staff on site we can etch pucks during a visit, if we are given advance notice to ensure the appropriate individual is on site. 

Whilst we have reduced number of on site staff members, please contact [email protected], and we will attempt to make sure that the pucks can be etched when sent to diamond.

Contact [email protected] to register new pucks, this should be a quick task, but is currently limited to Diamond staff. 

After the registration of the new container, then the shipmnet can be arranged.

On I23, what is the longest wavelength data collected that has provided high quality data for a SAD structure determination?

For S-SAD experiments we typically chose wavelengths between 2.7 and 3.0 A. Longer wavelengths can be used, but absorption and the current lack of analytical absorption corrections usually compromise the data quality, in particular plate-like crystals in low symmetry space groups. In addition, the longer the wavelength, the larger the diffraction angles, so for crystals diffracting to 2.5 A or better, the overall resolution and completeness will be affected (https://vimeo.com/264978830). Hence, the data collection strategies depend on parameters which are typically not considered at short wavelengths. For the time being all data is collected by beamline staff who are very well aware of the opportunities and limitations at long wavelengths. Please discuss potential projects the i23 team. 

What do you expect from BAG PIs and ACs besides registering samples?

Please follow the guidelines for responsive beamtime.

Should pucks for UDC and remote collection be sent in the same dewar?

No. They should be sent in seperate dewars.

What is the current turnaround from the receipt of samples to UDC? 

As of late june 2020, Most UDC samples are turned round within a week. This will change upon future demand and beamline availiability.  

For UDC should I over or under estimate my resolution?

• Eg sometimes the xtals diffract to 2.5 Å but more often to 2.8 Å . And often a higher dose can press the resolution from say 2.9 Å to maybe at least 2.7.

Use the highest resolution that is expected for the project, in this case 2.5 Å. if it is highly variable, consider using remote access instead.

Is there a preferred/recommended type of loop for automated collection?

No. Although it is necessary to use SPINE pins, see pucks and pins page. In general diffraction based centring is highly preferred for UDC samples, and should work with most loop types. Note that collection from multiple crystals is not possible in UDC.

Is possible to queue screening for the whole puck? 

Yes. As outlined in the video

After screening a whole puck is it possible to use the centring location used to screen ?

Currently this is not possibe.

Although it is possible to select similiar positional values after a reload, the pin will have moved sufficently that re-centring is advisable. 

Please discuss further requiremetns with you local contact, principal beamline scientist or [email protected]

Currently this is not possibe.

Although it is possible to select similiar positional values after a reload, the pin will have moved sufficently that re-centring is advisable. 

Please discuss further requiremetns with you local contact, principal beamline scientist or [email protected]