At the research reactor of the GKSS Forschungszentrum Geesthacht (about 200 km from Braunschweig), the PTB operates the polarization diffractometer POLDI for neutrons. For this complex instrument a remote control system has now been realized which allows more than 20 devices to be controlled. The control software available has been alter by adding extensions developed at the PTB and open source products available on the market so that the instrument can now be controlled from all over the world through the Internet.
Web interface: monitoring of power supply units with the browser, view of the sample environment with a webcam
For the control of the data acquisition, a TCP/IP (Internet protocol) based protocol has been developed and implemented in various programming and script languages, so familiar and well-tried program segments can be further used. Also, simultaneous access to different programs from different operating systems is possible.
The presentation of the instrument in the Internet is based on the open source projects LINUX, APACHE and PHP which are (the server-end) part of a web interface. By a browser (the client-end part of the interface) such as Netscape or Internet Explorer, an authorized user gets access to individual devices such as stepping motors, temperature controllers, meters, current sources. He is able to program measurement sequences, monitor and change device parameters or watch from Braunschweig the experimenter in Geesthacht.
Such experiments – which are also carried out with guests of the Geesthacht Neutron Facility – relate to magnetic model systems and technical materials. The diffractometer has also been used to develop equipment for investigating internal stresses in deformed materials and for determining material properties (spin-dependent n-cross section of 3He).
Contact at PTB:
Dipl.-Ing.(FH) Frank Kaufmann, TRA© Physikalisch-Technische Bundesanstalt, last update: 2011-11-17, Volker Großmann
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