A cryogenic rotation stage with a large clear aperture for the half-wave
plates in the Spider instrument
plates in the Spider instrument
File(s)
Published version
Accepted version
OA Location
Author(s)
Type
Journal Article
Abstract
We describe the cryogenic half-wave plate rotation mechanisms built for and
used in Spider, a polarization-sensitive balloon-borne telescope array that
observed the Cosmic Microwave Background at 95 GHz and 150 GHz during a
stratospheric balloon flight from Antarctica in January 2015. The mechanisms
operate at liquid helium temperature in flight. A three-point contact design
keeps the mechanical bearings relatively small but allows for a large (305 mm)
diameter clear aperture. A worm gear driven by a cryogenic stepper motor allows
for precise positioning and prevents undesired rotation when the motors are
depowered. A custom-built optical encoder system monitors the bearing angle to
an absolute accuracy of +/- 0.1 degrees. The system performed well in Spider
during its successful 16 day flight.
used in Spider, a polarization-sensitive balloon-borne telescope array that
observed the Cosmic Microwave Background at 95 GHz and 150 GHz during a
stratospheric balloon flight from Antarctica in January 2015. The mechanisms
operate at liquid helium temperature in flight. A three-point contact design
keeps the mechanical bearings relatively small but allows for a large (305 mm)
diameter clear aperture. A worm gear driven by a cryogenic stepper motor allows
for precise positioning and prevents undesired rotation when the motors are
depowered. A custom-built optical encoder system monitors the bearing angle to
an absolute accuracy of +/- 0.1 degrees. The system performed well in Spider
during its successful 16 day flight.
Date Issued
2016-01-08
Date Acceptance
2015-12-18
Citation
Review of Scientific Instruments, 2016, 87, pp.014501-014501
ISSN
1089-7623
Publisher
American Institute of Physics (AIP)
Start Page
014501
End Page
014501
Journal / Book Title
Review of Scientific Instruments
Volume
87
Copyright Statement
© 2016 AIP Publishing LLC
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/L00044X/1
Subjects
astro-ph.IM
astro-ph.IM
astro-ph.CO
Notes
11 pages, 7 figures, Published in Review of Scientific Instruments. v2 includes reviewer changes and longer literature review
Publication Status
Published
Article Number
014501
Date Publish Online
2016-01-08