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

2. 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

3. 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

4. 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: (
A lightweight field cage for a large TPC prototype for the ILC
P.Schade

5. 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

6. 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

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

8. 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

9. 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

10. 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

11. 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

12. 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!