Optimization of a dc SQUID magnetometer to minimize the field resolution

Author

Suzuki, K. ; Okabe, Y.

Author_Institution

Res. Center for Adv. Sci. & Technol., Tokyo Univ., Japan

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2172

Lastpage

2175

Abstract

The circuit parameters of a dc SQUID magnetometer have been optimized by computer simulations. Our principle of optimization is to minimize the field resolution. We have optimized the circuit parameters of a dc SQUID magnetometer, such as a Ketchen type, Drung type, directly-coupled type, etc. The only noise source was thermal noise from the shunt resistors. For a Ketchen type SQUID, our results show that the inductance of the input coil should be larger than that reported previously. It is also the case for a Drung type SQUID that the inductance of the SQUID washer coil should be slightly increased. By this design method, the optimum field resolution of a Ketchen type SQUID magnetometer is improved by a factor of 2/3. Furthermore, we compared the resolution of 3 types of dc SQUIDs and concluded that the optimum type of SQUID depends on the value of the critical current and the radius of the pick-up coil. Finally, we have proposed a new design method that can optimize the field resolution of dc SQUIDs under constraints on the critical current and the spatial resolution.<>

Keywords

SQUID magnetometers; circuit analysis computing; circuit optimisation; minimisation; DC SQUID magnetometer; Drung type SQUID; Ketchen type SQUID; circuit parameters; computer simulations; critical current; design; directly-coupled type SQUID; field resolution minimization; inductance; input coil; optimization; pick-up coil; shunt resistors; spatial resolution; thermal noise; washer coil; Circuit noise; Coils; Computer simulation; Critical current; Design methodology; Inductance; Magnetic circuits; SQUID magnetometers; Spatial resolution; Thermal resistance;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403014

Filename

403014