|For lectures, device demonstration, or lab courses we offer
asystem for measurements of current-voltage (IV) characteristics of electronic
devices. The system can be used for characterizing SQUIDs or Josephson
junctions, but also for testing or demonstrating other active or passive
|The I-V-characteristics measurement system consists of a 1 m long probe
with 12 mm diameter, which can be dipped into a helium storage dewar, and
a controller box having a size of 165 mm by 110 mm by 40 mm. A low-noise
instrumentation preamplifier (with a white voltage noise of about 1.2 nV
in 1 hertz bandwidth) and the low-noise current source are built into the
probe head. The IV-characteristics can be observed in real time on
an oscilloscope, or can be recorded on a personal computer. The full-scale
current range is from 1 mA to 5 mA, and the
gain of the voltage amplifier can be varied from 50 to 10000 in eight steps.
The box can be controlled by a personal computer via the serial port, or
manually, in case a computer should not be used.
|The IV Box connects to the serial port of a
personal computer. An easy to use program controls the settings and
records and displays the IV characteristics.
|For lab courses or class-room demonstration of the current-voltage
characteristics of Josephson junctions, the flux-to-voltage transfer function
of a SQUID, or Shapiro steps, the above shown probe can be shipped with
a niobium Josephson junction or dc SQUID.
|For class room demonstration or lab courses, we offer our inexpensive
microwave source MWS XG. The source generates microwaves at two frequencies
(various frequencies are available) with a variable output power of up
to 1 mW, and can be use to, e.g., show the frequency dependence of microwave-induced
steps in the current-voltage characteristics of a Josephson junction.