As computer hard- and software is evolving rapidly and the performance of the Internet is increasing, remote participation in physics experiments becomes feasible. Scientists still have to travel to research institutes to install and calibrate measurement equipment, but the need to be present at the experiment site during actual measurements is decreasing. To show the possibilities of remote participation, we built a demonstrator for experiments at the Textor94 tokamak, located at the Institut für Plasmaphysik (IPP) of the Forschungszentrum Jülich in Germany. Textor-94 is the main experimental facility of the three plasma physics institutes, located in the Netherlands, Belgium, and Germany, that collaborate in the Trilateral Euregio Cluster (TEC). In addition to video conferencing, participating scientists from external institutes can use the demonstrator to browse a measurement database, which contains a large part of the existing as well as newly measured data. Data that is measured by other participating institutions and stored in legacy formats is also available in the same database. Furthermore, scientists can monitor the current status of the tokamak, and there is a tool that allows them to remotely control measurement equipment. The architecture that underlies these tools is client/server based. Our demonstration clients run in Java-enabled web-browsers (for example Internet Explorer 4.0+ or Netscape Navigator 4.07+). They are available from a secured website, and can be evaluated by interested users from anywhere in the world. The servers are C++ programs, running on a variety of computer platforms. The clients communicate with the servers via CORBA IDL interfaces. End users who are connected to the Internet can access the servers directly from within their own computer (analysis) programs. Thanks to CORBA, users can write these programs in a large variety of programming languages, and on many computer platforms. CORBA IDL also makes co-development fairly easy: several institutes developed their own clients and servers, with little communication between the institutes during the development process. Still, the clients and servers worked correctly together after only a few minor adaptations. In this paper, we will present our experience with CORBA, the advantages mentioned above, and others, and we will cover some performance related issues. We will also present ideas to improve the performance by using CORBA's new component / POA based architecture.

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