The DAQ always runs - Performing large scale nuclear physics experiments

Licentiatavhandling, 2006

An important part and a growing field of modern subatomic physics is the study of exotic isotopes using radioactive beams. The experiments started out simple. Along with a better and more detailed understanding, together with the availability of new technology, the experiments are becoming more and more advanced. The increased complexity make the use of software at all levels, from data acquisition to analysis, evermore present. However, it is much more the vast amounts of data collected in each experiment, than the sophistication of the calculations needed, that mandates the use of computers. This thesis is about how to make difficult things simple again. The main thread throughout is that by acknowledging and understanding the complications, they can be used to overcome themselves. To take full advantage of the setups, it is necessary to make close ties between the data acquisition, slow control and analysis programs - they must be able to act as one. At the same time they must be decoupled enough, that any one part can be replaced without severely affecting the other. This is required in order that, while keeping coherence in the analysis procedures - the continuous improvement of the setups can take place without disrupting ongoing analysis work, also making new developments easily applicable to older data.