Morgan, Lewis & Bockius LLP
Apparatus and method for measuring second-order gradient of magnetic field using super conductor quantum interference device
An apparatus and method for measuring a second-order gradient of a magnetic field using a super conductor quantum interference device (SQUID) which obtains the second-order gradient of the magnetic field with a simple-constructed and low-priced measuring apparatus having three SQUID sensors and one differential circuit only. The apparatus includes first to third SQUID sensor driving circuits for detecting respective surrounding magnetic fields and outputting corresponding currents, respectively, a first coil for producing a magnetic field according to the current outputted from the first SQUID sensor driving circuit and feeding the produced magnetic field back to the first SQUID sensor driving circuit, a second coil for producing a magnetic field according to a sum of the currents outputted from the first and second SQUID sensor driving circuits and feeding the produced magnetic field back to the second SQUID sensor driving circuit, a third coil for producing a magnetic field according to a sum of the currents outputted from the second and third SQUID sensor driving circuits and feeding the produced magnetic field back to the third SQUID sensor driving circuit, and a differential amplifying section for differential-amplifying voltages outputted from the second and third SQUID sensor driving circuits.
LG Electronics Inc.
Y G
Y10S G01R
additional inventional
Byung Du Seung Min Seung Hyun
Oh Lee Moon