Historical research guide · 0047 · 1992
A possibility of gravitational force shielding by bulk YBCO superconductor
Podkletnov · Nieminen
In one minute
In 1992 Eugene Podkletnov and Risto Nieminen published a short paper in Physica C on a rotating bulk YBCO superconductor. Their apparatus used a sintered disc 14.5 centimetres across and 6 millimetres thick, levitated above an electromagnet in liquid-helium vapour. A non-conducting, non-magnetic 5.48-gram sample hung from an analytical balance above the disc. With high-frequency drive fields and rotation, they reported a decrease in the balance reading from 0.05 percent to about 0.3 percent, varying with rotation speed. The authors titled the report “A possibility of gravitational force shielding by bulk YBCO superconductor.” The material, geometry, temperature, driving fields, rotation, sample and balance are the apparatus record carried forward by this sheet.
Connection
Chapter 11 begins with the paper's apparatus and reported balance reading. The direct next work is to reproduce those variables together—disc formulation and geometry, low temperature, high-frequency field drive, rotation, sample and balance—and record the force and environmental channels on the same run.
From the source
A small non-conducting and non-magnetic sample weighing 5.48 grams, suspended from an analytical balance above a levitating bulk YBCO superconducting disc, was found to lose from 0.05 to 0.3 percent of its weight depending on the rotation speed of the disc.Abstract; results
The reported largest balance-reading decrease, around 0.3 percent, used high-frequency drive on the peripheral electromagnets and disc rotation at several thousand revolutions per minute; the reported reading varied with both rotation and driving fields.Experimental section; conditions for maximum effect
The disc is a sintered bulk YBa2Cu3O7−x ceramic, 14.5 centimetres in diameter and 6 millimetres thick, levitated by Meissner repulsion above a support electromagnet in liquid-helium vapour driven from 50 hertz up to the megahertz range, with two smaller electromagnets at the rim used to spin it.Experimental arrangement; apparatus figure
Podkletnov and Nieminen present the reported balance-reading decrease as a possibility of gravitational force shielding: a superconductor partially screening a body above it from the Earth's gravitational field.Title; discussion
The way in
https://doi.org/10.1016/0921-4534(92)90055-HHow to cite it
Podkletnov, Nieminen (1992) A possibility of gravitational force shielding by bulk YBCO superconductor doi:10.1016/0921-4534(92)90055-H