November 2009 saw the successful completion and handover of an international enhancement project that enabled JET to improve the quality and accuracy of density profile measurements significantly. The upgraded system is a reflectometer, which bounces microwaves off the plasma and measures the reflected waves, making it somewhat akin to radar. With this new system JET is now capable of measuring density profiles from the edge to the plasma centre with high spatial and temporal resolution for a wide range of magnetic configurations.

The KG10 Group (left to right): Luis Meneses (IST), Claudius Morlock (JET-CSU), Antoine Sirinelli (CCFE), Barry Alper (CCFE), Christine Bottereau (CEA), John Fessey (JOC), Tim Budd (CODAS), Trevor Edlington (JOC); Frederic Clairet (CEA); Mike Walsh (CCFE); Luis Cupido (IST)

Enhancement Programme 2 projects in general

Since 1999 JET has operated under the European Fusion Development Agreement, a legal framework signed between EURATOM and 27 European Associations. Hence our very essence is international collaboration. This applies to the exploitation of the JET machine as well as to all enhancement activities. Only the day-to-day or rather year-to-year maintenance and operation of JET is the responsibility of the so- called JET Operator.

In October 2007 a call for participation was launched to upgrade an existing profile reflectometer to a multiband system called KG10, allowing very accurate measurements in a wider range of plasma conditions than was possible before. Three Associations, CEA (France), IST (Portugal) and CCFE (UK) all declared their interest, with the latter selected for taking over the project leadership. The project teams were then constituted and a member of the JET Close Support Unit was appointed to coordinate the various partners and their activities as a kind of melting pot and central hub.

Early in 2008 the contractual framework for this project, with a value of about one million Euros, was signed and work started immediately. The project was under considerable time pressure, as it was desirable to have the system available for the already on-going 2008/2009 scientific campaign. The project members committed themselves to deliver the system not later than beginning of 2009, which gave the Associations approximately one year to finalise the design, effect the procurements and testing before shipping the equipment to JET. A strong leadership and close monitoring of the activities was essential, as the project had virtually no contingency

This is a three dimensional extract of 500 electron density profiles out of 30,000 taken during a 25 seconds lasting experiment at JET.

Interfaces needed

The critical path included the procurement of some very specialized microwave components which could not be procured in Europe. The successful and timely implementation of such an integrated multiparty project depends critically on a careful specification of the interfaces, so a dedicated interface control system, proper documentation, regular and frequent team meetings and internal approval procedures were all essential for coordinating the many different work packages. A project board kept a jealous watch over the progress and contributing to the success by picking up any issues as they arose.

As CEA and IST had proposed two different designs for the same diagnostics, it was decided to divide the microwave emitter/receiver units into two separate packages. IST covered the microwave bands in the frequency range of 33-110 gigahertz and CEA 50-150 gigahertz. CCFE was responsible for the data acquisition system as well as for developing the combiner system which integrated these units.

This division of tasks allowed the workload for the groups to be within limits and also considerably reduced the risk to the project, since different teams were working in parallel on independent parts of the system.

At the beginning of 2009 the hardware was delivered to JET, installed and commissioned in the following months. Since then many gigabytes of data have been recorded and are now available for all scientists at JET requiring refined profile measurements for their investigations, such as particle transport and magnetohydrodynamics. After the end of the campaign in 2009 the new diagnostics was than officially handed over to the fusion community.

The newly designed cage in the lab, holding emitter and receiver of the KG10 diagnostic.

A shining example

Running an international project is often considered a daunting challenge, because of the need not only to coordinate experts in different fields, but also people from different time zones, different cultural backgrounds and often with different motivations and goals. But this has been a way of life for many people since the beginning of the JET project and will be even more so in the future, as fusion research becomes increasingly globally integrated. It is the result of the many years’ effort in Europe to strengthen the fusion community, diversifying capabilities while keeping a healthy level of competition.

Applying modern project management is still relatively new to research activities, but nevertheless on a steep development path given the increasing pressure to deliver results on time and budget.

The KG10 project is a very nice example of highly capable and motivated people teaming up to achieve something extraordinary. There is no doubt that excellent management was one of the keys to success. Project leader Mike Walsh said: “We have promised to deliver on time, so let’s go and do it!”

Claudius Morlock

Diagnostics at JET

JET is equipped with about 100 diagnostics that are in routine use, covering all the major measuring techniques used not only in plasma physics but more generally in experimental physics. This set of diagnostics can produce up to 18 gigabytes of data per shot and in the last campaign half a terabyte of data was collected. JET diagnostics involve about 100 people on site and during the campaigns between 30 and 40 per cent of the scientists come to JET to work on diagnostics.