A New Spin on Photoemission Spectroscopy Page: 86 of 259
This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
Figure 2.17. Main chamber sample goniometer and cryostat. Goniometer itself provides 3
and 0 rotations. The entire cryostat assembly is mounted on a rotary seal to provide the 0
rotation. Sample stage is connected to tip of cryostat by flexible copper braiding.
2.7.3 Sample manipulation
During ARPES or LEED measurement, a sample(puck) is mounted on a 2-axis goniome-
ter at the end of a cryostat designed, built, and maintained by John Pepper and his group
at the ALS. Sample pucks are loaded into the goniometer and locked into place in a similar
way to scheme used in the Load-Lock and sample storage chambers (Figure 2.16). The
goniometer has its own integrated e-beam heater assembly for flash heating samples in the
main chamber. It also has two integrated rotational motions: a tilt stage to rotate about
the red axis (13 in the discussion in section 2.3 and figure 2.6), and a rotational stage to spin
about the pink dot (0) for azimuthal alignment of the sample's crystallographic axes. The 0
rotation (section 2.3 and figure 2.6) is provided by rotating the entire cryostat/goniometer
assembly on a dual-stage differentially pumped rotary seal. The goniometer is held at
the end of a vertically mounted liquid He cryostat and thermally connected to the cryotip
through a flexible copper braid. This scheme can bring the sample puck to as low as ~12K.
A resistive heater is mounted near the cryotip for regulating temperatures above this base
temperature up to room temperature. The copper braid is thermally connected to the
cryotip through a sapphire plate which provides good thermal conductivity and electrical
isolation such that the sample puck can be floated to high voltage for e-beam heating as
well as allowing a measurement of the magnitude of the photoemission current during an
Here’s what’s next.
This document can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Thesis Or Dissertation.
Jozwiak, Chris. A New Spin on Photoemission Spectroscopy, thesis or dissertation, December 1, 2008; United States. (https://digital.library.unt.edu/ark:/67531/metadc1014237/m1/86/: accessed April 22, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.