Important information when writing proposals
For current information about proposal calls, see the corresponding page under User access > Call for proposals
Important information for those considering submitting proposals:
- The spin-resolved ARPES endstation currently only has a 4-axis manipulator. The analyzer is capable of deflection, which slightly eases the problem. Upgrading to a 6-axis is a high priority, but for now consider carefully whether your proposed experiment is still possible with only X/Y/Z/Polar degrees of freedom for alignment, and explicitly address this point in your proposal.
- The spin-resolved ARPES endstation will have demonstrated baseline functionality and formally left commissioning, but will still be very new. You are not yet applying for a perfect, polished beamline. We’re working hard, but it’s possible that we could still be trying to optimize the spot size down to the final 10x10um target when you arrive, or that the control and measurement software still cause frustration.
- Shorter beamtimes will now be considered. Until now, Bloch has awarded only 30 shift / 5-day beamtimes (Wed 0800 — Monday 0800). To increase access, we will now also consider shorter beamtimes of 2-3 days. You can either directly propose a reduced scope experiment, or apply for a full 5-day experiment but add a note about whether you would consider a shorter allocation and what the consequences of that would be for your proposal. If you end up being ranked close to the cutoff, this could make the difference between being award beamtime or not.
- In addition to the basic information available on this website, the full beamline documentation page is available at https://blochdocs.maxiv.lu.se/
Bloch is oversubscribed, so proposals should be compelling and carefully written in order to be chosen by the advisory committee. You are always welcome to send proposal drafts to the beamline staff ahead of the deadline if you would like feedback (but note that beamline staff are not involved in the evaluation process).
For those seeking advice regarding proposal writing, here are some basic guidelines. Your job it is to make it very easy for a reader, who is at the level of a senior scientist but might not be familiar with your specific system or physics, to quickly understand:
- What you want to do (i.e. what exactly will you measure)
- Why that would be an interesting thing to do (i.e. what is the science question)
- How this relates to prior studies (i.e. will this advance the field or just repeat something that has already been done?)
- What the expected results are, and how they would answer your science question
- Whether the experiment (including analysis) is likely to work. Showing preliminary data or characterization measurements is usually a good way to address this (e.g. could there be doubts about being able to grow/prepare the sample? Are you trying to disentangle features or processes that might not in fact be possible to disentangle?)
- Why you need Bloch (i.e. could this be done in a home lab with a UV lamp or laser?)
- Whether it is technically feasible to do at Bloch (i.e. are you assuming a measurement temperature of 5K? Expecting to do SX-ARPES at 1000eV?)
|Optical microscope||Available in chemistry lab (SMZ745T)|
|Blank sample plates in Al or OFHC Cu||Available|
|Conductive epoxy||Available (Epotek H21-D)|
|Top posts for cleavable samples||Available in limited quantity and sizes, safer to bring your own if possible|
|Hot plates and microgram scales||Available in chemistry lab|
|Ultrasonic solvent cleaning||Available in chemistry lab|
|Wet chemical processing (acids/bases)||Available with advanced notice|
|UHV evaporators||Available with advanced notice (EFM-3, EF 40C1)|
Remote access is always available in a hybrid mode (some people on-site, some people at home) and in rare cases full remote (nobody here in person, staff handle sample loading and transfers). Remote access users have full access to the measurement and beamline controls.
We encourage users to arrive before the beamtime officially begins, in order to make all necessary preparations and be ready to start measuring as soon as the beam becomes available.
Both endstations at Bloch are configured for Omicron flag-style sample plates, both the regular flat type and the built up ‘direct heating’ type. We keep a large stock of copper and aluminium flat plates for experiments that do not involve heating above 100°C. For preparations involving heating above 100°C, molydenum sample plates of both types are available at the beamline for general use. These plates are shared among all users; if your experiment is particularly sensitive to contamination then you may need to either clean the plate first or bring your own.
Sample heights of at least 20mm are OK for ARPES. Transfer into the STM chamber will become impossible for sample heights over 5.9mm (measured from the surface of the sample plate)
If you bring your own sample plates, carefully check their compatibility with our systems. In particular:
- The side edges (marked below as ‘Keep out’) should be within about 50um of 1mm thickness. Elsewhere on the plate the thickness is not important.
- The hole in the tag makes transfers easier but is not mandatory
- The small ‘wings’ at the tag end of the plate make transfers easier (by preventing over-insertion) but are not mandatory
- Avoid having anything extend past the leading edge of the sample plate (i.e. the edge opposite the tag)
‘Fast entry source ports’ are CF40 ports on the two preparation chambers where a gate valve and a short pumping T-piece have been installed. If a source is mounted to this port using a linear translator, it is possible to introduce it within 8-12 hours, without needing to vent the chamber. Contact beamline staff for details and size requirements if this will be of interest.