Computer Setup

A major part of this work was to install a new computer and software environnement for the control of the measurements in the flow cryostate. For technical informations about this installation please see appendix . In this section we only want to give a quick outline of the present installation in the flow cryostate as well as in the dilution refrigerator.

In the setup of the flow cryostate we have a central control computer with the program SeveNMR running on it. This program offers a very simple command language to control every component of the NMR spectrometer and of the cryostate. A detailed schematic plot is given in figure . Further more we can control the pulses, which are sent from a computer board, and the data acquistion with that command language. As an important feature SeveNMR can also read these commands from a script file, what makes it very easy to implement even complex automated measurements. A very simplified overview of what SeveNMR is doing is shown in figure .

  

Figure: Overview over the basic functionality of SeveNMR

After the data is acquired it can either be imported to Matlab for further processing or it can be processed directly in SeveNMR, but this is quite a slow option.

We don't want to go too far into details about the setup of the dilution refrigerator because it will be exchanged soon. The main difference is that there is a variety of software programs to perform different measurements. The data is acquired by a Le Croy transient recorder and transferred to the computer. The pulses are sent from an external pulse programmer RS-670 which is connected to the computer over a serial RS 232 interface.