Demonstration of the Meissner Effect Using Superconducting Y

2

BaCuO

5

(YBCO)

Michael Moore College of the Redwoods Superconducting Magnet Program Lawrence Berkeley National Lab

Y 2 BaCuO 5 is a High Temperature Superconductor The critical temperature(Tc) is the temperature at which a material becomes superconductive

160 140

Hg0.8TI0.2Ba2Ca2Cu2O8.33

120

Bi1.6Pb0.6Sr2Ca2Sb0.1Cu3Oy

100

Bi2Sr2CaCu2O9

80

LN-80 K YBa2CuO5 LHe-4.2 K

60

(La,Sr,Ca)3Cu2O6

40

Nb3Si

20

Nb3Sn

0

Hg

YBCO is a Type II Superconductor 0 Ω Non-superconductive metals • Type I has a much sharper transition to Type II superconductivity and exhibits perfect Type I diamagnetism • Type II allows flux pinning and has a higher Tc 0 K T c • The Meissner Effect only occurs in Type II

Superconductivity Creates Diamagnetism The surface of the YBCO assumes the same Flux value as the external flux from the magnets and allows none of it to enter the YBCO’s interior.

Because Like poles repel each other, the YBCO is levitated

Impurities in the YBCO Causes Flux Pinning Diamagnetism in superconducting material Impurities(non-superconducting materials) pin flux lines in flux lattice votices

The Meissner Effect is a Combination of Diamagnetism and Flux Pinning Permanent Magnet Type II superconductor The classic Meissner Effect demonstration

Flux Density and Magnetic Flux Lines of Track Configuration Low Density Flux Lines Permanent Magnets High Density

The YBCO will only move along the track

YBCO

•Flux Pinning will only allow flux lines of the same value to enter the vortexes •Since the values only stay the same in a line parallel to the track, the YBCO only moves in that direction

Liquid Nitrogen Cools the YBCO Below its Tc Liquid Nitrogen When the LN boils away, the YBCO stays superconducting for ≈ 3 minutes YBCO

Acknowledgements I would like to thank my mentor, Stephen Gourlay for his guidance and support on this project, Zach Radding for Design works’ involvement, Kathleen Weber for helping me get used to lab culture, Ron Scanlen, Dan Dietderich, GianLuca Sabbi and Shlomo Caspi for their help with the properties of superconductors, Jim Swithwick for computer assistance, Alan Lietzke for putting up with my love for gauss meters, Jim Swanson, Hugh Higley, Scott Bartlett, Ray Hafalia, Roy Hannaford, and Nate Liggens who all helped immensly with tools and inspiration. A big thanks to Goli Modeste who took the time to machine parts for me. Jon Zbasnik was a great inspiration, and Dawn Faessler and Tom Martin were great friends that made work more enjoyable. Thanks to Sara Mattafirri for sharing her space with me. I would also like to thank Laurel Egenberger, Susan Aberg and everyone at CSEE who made this summer a fulfilling one. Last but not least, thanks to the U.S. Department of Energy, Office of Science. The research described here was performed at the Lawrence Berkeley National Laboratory and funded by the Department of Energy Office of Science under Contract No. DE-AC03-76SF00098.