A-branch – ARPES

The A-branch is open for general users. Beamtime allocations are made in units of a half week or a full week depending on their complexity (1 week = typically 5 or 6 days, 30 or 36 shifts).

The A-branch endstation consists of several UHV chambers, coupled by a central radial distribution chamber. This layout permits working in parallel on each chamber, independently of all others.

For details of the measurement chamber, the two preparation chambers and the scanning tunnelling microscope, see the dedicated pages. The other components of the endstation are:


The loadlock has a 6-slot carousel. Preliminary outgassing is possible by either direct current heating through the sample or resistive heating by a filament underneath the receiver. At present only one sample can be heated at a time. It takes about 2 hours to attain a satisfactory pressure to move the sample into the main chambers.

Vacuum suitcase

It is possible to dock vacuum suitcases to the endstation. Please discuss the details of your suitcase with the beamline staff to ensure compatibility.

Storage chamber

There is a 12-slot carousel for short-term UHV storage of samples

Transfer chamber

The central transfer chamber (P=9×10⁻¹¹mbar) has a distribution arm with two thermally isolated slots. The receiver can be LN2 cooled to enable cold (<100K) transfers between chambers.

Free ports

There is one free DN63CF port on the transfer chamber which could in principle accommodate a small custom chamber. Discuss with the beamline staff, many months in advance, if you are interested in using this.

B-branch (spinARPES)

The B-branch is currently open for general users. Since it is a much newer station and a more complicated apparatus, applicants are encouraged to contact beamline staff to discuss experimental plans before submitting proposals. Due to the increased difficult of spin-ARPES experiments, currently only full-week allocations are awarded.

The beamline optics for the B-branch of Bloch are essentially identical to those of the A-branch, but here the experimental endstation offers spin-resolved ARPES.

The analysis chamber is equipped with a PHOIBOS 150 hemispherical analyzer from Specs, with a combined 2D-CCD for regular ARPES and 3D-VLEED for spin resolution. This analyzer is capable of electronic deflection to simulate polar or tilt rotations without moving the sample. The expected (but not yet verified) energy resolution with the CCD detector is <5meV, with angular resolution <0.1°.

Measurement of all three spin vector components is accomplished with a single Ferrum VLEED detector combined with a magnetic spin-rotator lens. For more details about this setup see the beamline documentation pages

Currently, the analysis chamber uses a 4-axis closed-cycle cryomanipulator, with an expected sample temperature range of 15K –> 400K. A 6-axis cryomanipulator will be procured during 2024.

Sample preparation by cleaving, sputtering, heating or evaporation is possible.

Page manager: Craig Polley February 2, 2024