Quantum Design PPMS Instrument Cart

The QD PPMS Instrument Cart connects to the 14-pin LEMO connector on the exterior of the Quantum Design  PPMS instruments and diverts the signal to a custom breakout box that allows users to read or source each pin separately.  Also included on the cart are a Keithley Model 2450 SourceMeter, a Stanford Research Systems Model SR830 Lock-in amplifier, and a control computer with network access to these instruments and the sample chamber of the PPMS.

The Keithley 2450 is a source monitor unit which can source voltages over the range 20 mV – 200 V or currents over the range 10 nA – 1A with 0.012 % basic accuracy or read either with an order of magnitude better precision. The SR830 is a dual-phase lock-in amplifier, which can simultaneously show the magnitude and phase of an input signal over the frequency range 10 mHz – 102 kHz with a minimum full-scale input voltage sensitivity of 2 nV and 0.01° phase resolution. It also has a direct digital synthesis source which can generate single-frequency sine waves over the same dynamic range with 4 digits of precision. The control computer contains Python code which can control both these instruments and the temperature, field, and rotation angle parameters in the PPMS sample chamber. Pre-written sequences exist which can use this capability to measure AC resistance as a function of temperature, field, angle and gate voltage in the frequency range 0.001 mHz – 10 kHz. For alternate measurement configurations and sequences, please consult with the instrument scientist.