status of the second field cage Fieldcage II status of the second field cage Volker Prahl ECFA Workshop DESY 2013 31.05.2013 Bernd Beyer, Ole Bach, Vitalij Peer

Mechanical status of the field cage II Overview Mechanical status of the field cage II Field cage I, short review Mandrel Next tasks Dummy cage Field cage II Mounting tool Outlook

Mechanical status of the field cage II Field cage I, short review Specific reasons to build a new field cage Misalignment of the rotational axis of the field cage Fig.2 To gain experience in composite materials and fabrication Design improvements

Mechanical status of the field cage II Field cage I, short review r = 0.87±0.07mrad Fig.1 Fig.2 Design parameter of the field cage Measured parameter of the field cage See also: (http://iopscience.iop.org/1748-0221/5/10/P10011) A lightweight field cage for a large TPC prototype for the ILC P.Schade

Mechanical status of the field cage II Mandrel Fig.4 Flat and surface for Support pin on both sides Fig.3 Mandrel with field strip layer Screw to adjust the diameter Fig.4, 5 Mandrel after machining Fig.5

Actual tools Mandrel actual status After decreasing you cant adjust the mandrel to the right diameter again OD after machining on the lathe 1.6mm less than design value this is the min dia. accepted of the length of the field strip foil Preparation for the support pins in progress Preparation for gluing tests in progress

Mandrel Geometrical values after machining OD is 1.6mm less than design value of 720.0±0.3mm

Mandrel Machining now in progress Very precise arrangment necessary Next tasks Mandrel Machining now in progress Very precise arrangment necessary Design of the support structure in progress Fig.5 Adjustment of the Mandrel Fig.6 Support structure by Ole

Dummy cage To gain experience in: Fabrication of composite materials Next tasks Dummy cage To gain experience in: Fabrication of composite materials How to glue the end flange (solid ring or single parts) To get experience how precise we can build the field cage Improve the technologie Is it possible to slide the cage over the mandrel without degreasing Discover unknown issues

Field cage II Design improvements Other tasks Next tasks HV contact of first and seventh field strip Threaded inserts in end flange plastic with low Xo? Optimized wall design GFK, Nomex New field strip foil? Only one in usable condition Other tasks Mounting tool Cathode Field cage position measuring

Mounting tool Next tasks First test are done Short modification to reduce the play in progress Final tests provided in June Fig.7 Mounting tool / alignment plate

Thank you! Outlook Mandrel Material has to be orderd Dummy field cage Field cage II Support structure of the cathode Mounting tool Stage maintenance Thank you!