Project Title:
Two Stage DC SQUID Amplifiers for Cryogenic Sensors
HYPRES,Inc.
175 Clearbrook Road
Elmsford, NY 10523
93-1 08.14 1190 Amount Requested $69,683.00
Two Stage DC SQUID Amplifiers for Cryogenic Sensors
Abstract:
Superconducting Quantum Interference Devices (SQUIDs) are extremely
sensitive detectors of magnetic flux and can be used as low noise
amplifiers for many applications such as cryogenic detectors and
biomagnetic measurements. In order to utilize a SQUID as an
amplifier, extensive peripheral electronics are required. Such
room temperature electronics are very expensive, specially for
space-qualified applications, and are responsible for a substantial
portion of the cost of the commercial magnetometer systems.
Therefore, it is highly advantageous to simplify the electronics
required to operate SQUIDs. This project will lead to the
development of an all thin-film SQUID array amplifier chip. The
proposed DC SQUID amplifier integrates several (on the order of a
hundred) DC SQUID gates with a high sensitivity analog SQUID
magnetometer. Each chip, in addition to having a SQUID array
coupled to an analog SQUID, will also have an integrated
superconducting transformer to facilitate its interface to an
external pick up coil. This scheme will eliminate the need for the
most critical part of the peripheral electronics, that is, the low
noise amplifiers, which, in practical systems, determines the noise
floor of the systems. Such a system will be compact and cost
effective, and requires ordinary support electronics. As a result
of this effort, it will be possible to design and fabricate SQUID
chips that will contain arrays of such SQUIDs for integration in
magnetometer systems, thereby reducing the complexity of the room
temperature electronics for such systems. Due to significant
progress in superconducting electronics at HYPRES in recent months,
we are actually proposing to design, fabricate and evaluate these
SQUID array amplifier chips under this phase I program. The goal
for the flux noise for such chips is less than 5XlO-6~o/~Hz when
operated from 4.2 K down to milliKelvins.
This project will lead to the development of an all-thin film SQUID
chip where the chip has a self-contained low noise analog SQUID
amplifier with on-chip SQUID arrays as amplifiers. This chip will
require ordinary support electronics and consequently systems
containing a few such chips can be realized very cost effectively
for integration in SQUID magnetometer systems.
SQUID magnetometer, Low noise amplifier, Non-destructive evaluation