Imperial College London

Carlo R. Contaldi

Faculty of Natural SciencesDepartment of Physics

Professor of Theoretical Physics



+44 (0)20 7594 1527c.contaldi




505Huxley BuildingSouth Kensington Campus






BibTex format

author = {Bryan, S and Ade, P and Amiri, M and Benton, S and Bihary, R and Bock, J and Bond, JR and Chiang, HC and Contaldi, C and Crill, B and Dore, O and Elder, B and Filippini, J and Fraisse, A and Gambrel, A and Gandilo, N and Gudmundsson, J and Hasselfield, M and Halpern, M and Hilton, G and Holmes, W and Hristov, V and Irwin, K and Jones, W and Kermish, Z and Lawrie, C and MacTavish, C and Mason, P and Megerian, K and Moncelsi, L and Montroy, T and Morford, T and Nagy, J and Netterfield, CB and Padilla, I and Rahlin, AS and Reintsema, C and Riley, DC and Ruhl, J and Runyan, M and Saliwanchik, B and Shariff, J and Soler, J and Trangsrud, A and Tucker, C and Tucker, R and Turner, A and Wen, S and Wiebe, D and Young, E},
doi = {10.1063/1.4939435},
journal = {Review of Scientific Instruments},
pages = {014501--014501},
title = {A cryogenic rotation stage with a large clear aperture for the half-wave plates in the Spider instrument},
url = {},
volume = {87},
year = {2016}

RIS format (EndNote, RefMan)

AB - We describe the cryogenic half-wave plate rotation mechanisms built for andused in Spider, a polarization-sensitive balloon-borne telescope array thatobserved the Cosmic Microwave Background at 95 GHz and 150 GHz during astratospheric balloon flight from Antarctica in January 2015. The mechanismsoperate at liquid helium temperature in flight. A three-point contact designkeeps the mechanical bearings relatively small but allows for a large (305 mm)diameter clear aperture. A worm gear driven by a cryogenic stepper motor allowsfor precise positioning and prevents undesired rotation when the motors aredepowered. A custom-built optical encoder system monitors the bearing angle toan absolute accuracy of +/- 0.1 degrees. The system performed well in Spiderduring its successful 16 day flight.
AU - Bryan,S
AU - Ade,P
AU - Amiri,M
AU - Benton,S
AU - Bihary,R
AU - Bock,J
AU - Bond,JR
AU - Chiang,HC
AU - Contaldi,C
AU - Crill,B
AU - Dore,O
AU - Elder,B
AU - Filippini,J
AU - Fraisse,A
AU - Gambrel,A
AU - Gandilo,N
AU - Gudmundsson,J
AU - Hasselfield,M
AU - Halpern,M
AU - Hilton,G
AU - Holmes,W
AU - Hristov,V
AU - Irwin,K
AU - Jones,W
AU - Kermish,Z
AU - Lawrie,C
AU - MacTavish,C
AU - Mason,P
AU - Megerian,K
AU - Moncelsi,L
AU - Montroy,T
AU - Morford,T
AU - Nagy,J
AU - Netterfield,CB
AU - Padilla,I
AU - Rahlin,AS
AU - Reintsema,C
AU - Riley,DC
AU - Ruhl,J
AU - Runyan,M
AU - Saliwanchik,B
AU - Shariff,J
AU - Soler,J
AU - Trangsrud,A
AU - Tucker,C
AU - Tucker,R
AU - Turner,A
AU - Wen,S
AU - Wiebe,D
AU - Young,E
DO - 10.1063/1.4939435
EP - 014501
PY - 2016///
SN - 1089-7623
SP - 014501
TI - A cryogenic rotation stage with a large clear aperture for the half-wave plates in the Spider instrument
T2 - Review of Scientific Instruments
UR -
UR -
VL - 87
ER -