Research On Magnetic Interference In Test Of Weak Equivalence Principle With A Rotatable Torsion Balance

Since modern physics has achieved the great development, Einstein treat the weak equivalence principle as a assumption, and then established the general theory of relativity and almost all of the test are proved the correctness without exception. However, between the general theory and quantum theory has some irreconcilable contradictions, theoretical physicists have been pursuing a "unified", "universal" theory. However, all attempts to unify the ultimate theory is, without exception, request breaking weak equivalence principle, so high precision test of the weak equivalence principle have great scientific significance.The weak equivalence principle test as a gravitational experiment, as we all know, gravity is very weak, so experimental environment interference should make a detailed assessment and accurate control in order to faint the gravitational signals.Our laboratory test the weak equivalence principle with a rotatable torsion balance, as the highest precision torsion balance experiments base on the grand, each error requirements are stringent, and the contribution of natural geomagnetic field is one of the major error terms. Our initial target level is, This paper focuses on impact of magnetic field on the experiment. Including:(1) Detailed analysis the mechanism of magnetic field effect. After making precision measurement of the magnetic moment of the torsion balance, we find that if don't reduce the magnetic effect, the geomagnetic field in the experiment influence will reach,more than three orders of magnitude larger than the target level which gives the demand of magnetic field shielding.(2) In order to design the magnetic shields which will meet the needs of the experiment, using the help of simulation and construct simulation model. Then we design a magnetic shields whose shielding effect will over 5000 times(3) Testing the designed magnetic shields and finding the ion pump affect the magnetic shielding effect a lot in experiments. So we shield the ion pump and further improve the magnetic shield design, at last we directly measure the magnetic shields shielding effect which multiples have reached more than 5,500 times. The final residual effect less than ?~1.6×10-12, achieve the desired goal. This work will provide guidance and help in higher precision experiment and higher shielding effect shield design.