IPP Annual Report 2007 - Max-Planck-Institut für Plasmaphysik ...

6.1 Bus-bar System
The manufacturing of bus-bars continued. The first set of
conductors for the first module was delivered. The manufacturing
of bus-bars runs routinely. The design of mechanical
supports for the bus-bar systems has been further
developed. The associated drawings are partially approved.
Supports had to be redesigned since several clashes with
surrounding components were detected. Assembly tests
with dummy bus-bars were successfully made together
with FZJ. Technicians from INP in Krakow were trained for
the bus-bar installation. The joint-prototype test at the
Efremov Institute was completed. The welding procedure
for the bus-bar joints is finished. Practical installation exercises
have started under real on-site conditions. Construction
works for the current lead joint-prototype were continued.
First practical works with dummies are made. These
works are continued in 2008. The specification for the
wiring and insulation of the quench-detection system was
further developed. The qualification and delivery of insulation
parts was contractually bound. Some difficulties arose
at the manufacturer with respect to the proper handling of
the rather liquid resin.
Figure 21: 1st set of bus bars in the bus bar preparation area
The bus-bar preparation was set-up, all tooling and rigs
were provided and installed. Additional engineers and technicians
from INP in Krakow will be trained and integrated
into the bus-bar assembly team. Again problems with the
aluminium welds at the coil terminals occurred. Small
cracks at production proof samples were detected. The
welding process was refined, however, the limits of feasibility
have already been achieved. In terms of the assembly
schedule more bus-bar works were moved to the preparation
phase; away from the critical path. As a result additional
assembly works on the bus-bar system can now be carried
out without influencing the overall project time plan.
Wendelstein 7-X
48
6.2 Vacuum Technology
The work packages of the vacuum technology group in 2007
were continued as in 2006. Main tasks were: leak detection
on single components and monitoring of leak tests at suppliers
(Tesla, Ensa, BNG) as well as leak and Paschen tests
on coils and on cryo piping of thermal insulation during the
coil preparation and assembly. The works at Tesla were
finalized at the end of 2007. Local leak tests with diverse
test chambers for superconductor connections and cooling
pipes at room temperature and at 77 K (if technically necessary)
are routinely implemented during assembly. The design
of these test-chambers as well as the qualification of the
tests was further continued. Qualification tests of materials
and devices concerning the suitability in vacuum (outgassing
rates, Paschen stability) were realised in a laboratory.
Little progress was achieved on the specification of the
vacuum systems since it depends on the progress of the layout
in the torus hall.
6.3 W7-X Assembly
The work in the component preparation, especially on coils
and plasma vessel sectors, has been continued as planned.
Components for the second module are being prepared. The
works are running routinely. The scope of scanning works
on these components was considerably extended. As a result
additional external resources had to be hired. Additional
storage capacity for prepared components outside the institute
was refurbished and put into operation.
Figure 22: PV sectors during the test assembly – rigs are sliding on air
cushions
Additional staff was hired to cope timely with the expanded
preparation works. There were, however, hardly any technological
changes in the coil preparation. Therefore, one can
consider the qualification of the coil preparation as completed
from today’s point of view. With respect to the preparation