TY - JOUR
T1 - A cosmic microwave background radiation polarimeter using superconducting bearings
AU - Hanany, Shaul
AU - Matsumura, Tomotake
AU - Johnson, Brad
AU - Jones, Terry
AU - Hull, John R.
AU - Ma, Ki B.
PY - 2003/6
Y1 - 2003/6
N2 - Measurements of the polarization of the cosmic microwave background (CMB) radiation are expected to significantly increase our understanding of the early universe. We present a design for a CMB polarimeter in which a cryogenically cooled half wave plate rotates by means of a high-temperature superconducting (HTS) bearing. The design is optimized for implementation in MAXIPOL, a balloon-borne CMB polarimeter. A prototype bearing, consisting of commercially available ring-shaped permanent magnet and an array of YBCO bulk HTS material, has been constructed. We measured the coefficient of friction as a function of several parameters including temperature between 15 and 80 K, rotation frequency between 0.3 and 3.5 Hz, levitation distance between 6 and 10 mm, and ambient pressure between 10-7 and 1 torr. The low rotational drag of the HTS bearing allows rotations for long periods of time with minimal input power and negligible wear and tear thus making this technology suitable for a future satellite mission.
AB - Measurements of the polarization of the cosmic microwave background (CMB) radiation are expected to significantly increase our understanding of the early universe. We present a design for a CMB polarimeter in which a cryogenically cooled half wave plate rotates by means of a high-temperature superconducting (HTS) bearing. The design is optimized for implementation in MAXIPOL, a balloon-borne CMB polarimeter. A prototype bearing, consisting of commercially available ring-shaped permanent magnet and an array of YBCO bulk HTS material, has been constructed. We measured the coefficient of friction as a function of several parameters including temperature between 15 and 80 K, rotation frequency between 0.3 and 3.5 Hz, levitation distance between 6 and 10 mm, and ambient pressure between 10-7 and 1 torr. The low rotational drag of the HTS bearing allows rotations for long periods of time with minimal input power and negligible wear and tear thus making this technology suitable for a future satellite mission.
UR - http://www.scopus.com/inward/record.url?scp=0042473287&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0042473287&partnerID=8YFLogxK
U2 - 10.1109/TASC.2003.813016
DO - 10.1109/TASC.2003.813016
M3 - Conference article
AN - SCOPUS:0042473287
SN - 1051-8223
VL - 13
SP - 2128
EP - 2133
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 2 II
T2 - 2002 Applied Superconductivity Conference
Y2 - 4 August 2002 through 9 August 2002
ER -