Design of the modifications of the dilution refrigerator can be started as soon as the dimensions of the new magnet are fixed. Some of the new parts have to be fabricated outside the workshop of Helsinki University of Technology. This concerns especially the microwave cavity and the target holder (precision sheet metal workshop), the mixing chamber (superfluid leaktight reinforced plastic technology) and the sintered heat exchanger (vacuum oven and electron beam welding machine). CERN workshops would be a natural choice because of their former experience.
Table 3.2:
Schedule for the modifications of the dilution refrigerator.