Tracker Solenoid
Module Design
Update
Steve Virostek Stephanie Yang
Mike Green Wing LauLawrence Berkeley National Lab Oxford Physics
MICE Collaboration Meeting October 23, 2005
Tracker Module Design Update
Steve Virostek - LBNL Page 2
Design Update Summary
Changes to baseline design:
• Modified coil geometries (covered in Mike Green’s talk)
• Increased outer vessel diameter to match AFC & RFCC modules
• Designed new support stand similar to RFCC module
• Developed new concept for magnetic shielding support
Design and analysis progress:
• Preliminary 3D model of the updated module design is complete
• FEA modeling of the support stand, end plates and magnetic shielding is done
• Vessel shell designed to meet pressure vessel code requirements (PD 5500)
Upcoming Tasks:
• Integrate radiation shutter with tracker module outer vessel in 3D model
• Complete full model, coupled load analyses and refine design
• Perform a vacuum system analysis including the effects of fields on pumps
• Develop a specification for procurement of the tracker solenoid module
Tracker Module Design Update
Steve Virostek - LBNL Page 3
Tracker Module 3D Model
Magnetic shielding
Cold mass supports
Radiation shutter
Steel tube supports
Cryocooler port
Magnetic shieldingsupports
Coil lead feedthrough
Side plates
Tracker Module Design Update
Steve Virostek - LBNL Page 4
Design of the tracker module support stand
Vessel and Stand 2D Drawing
10mm thick plate
100 x 100 x 5 box section
Tracker Module Design Update
Steve Virostek - LBNL Page 7
Vessel and Support Analyses
•FEA of outer vessel and support subject a uniform, circumferentially distributed 50 ton axial load on vessel
•FEA of end plate and inner tube due to external pressure
•Hand calculation of end plate due to external pressure
•Hand calculation of outer vessel due to external pressure
•FEA of magnetic shielding support subject to gravity only
•FEA of magnetic shielding support subject to uniformly distributed 50 ton axial force
Tracker Module Design Update
Steve Virostek - LBNL Page 8
Vessel & Support FEA Results
50 ton, uniform axial load on vessel; fully fixed at support stand base
Max stress: <100 MPa
Tracker Module Design Update
Steve Virostek - LBNL Page 9
Vessel & Support FEA Results
50 ton, uniform axial load on vessel; fully fixed at support stand base
Max deflection: 1mm
Tracker Module Design Update
Steve Virostek - LBNL Page 10
End Plate & Inner Tube FEA
0.1 MPa external pressure; outer edges of end plates are fixed
Max stress: 128 MPa
Tracker Module Design Update
Steve Virostek - LBNL Page 11
End Plate & Inner Tube FEA
0.1 MPa external pressure; outer edges of end plates are fixed
Max deflection: 0.7 mm
Tracker Module Design Update
Steve Virostek - LBNL Page 12
End Plate Analysis (hand calc.)
50 mm
200 inner radius
700 mm radius
650 mm outer radius
Roarke’s Handbook covers the case of an annular disk
subjected to uniform pressure and with fully fixed inner
and outer edges (similar to our case):
Max. bending stress = 145 MPa
Max. deflection = 0.6mm
FEA modeling results gave 128 MPa stress and 0.7 mm
deflection for the end plates – this difference is expected
since the edges are not fully fixed
PD 5500 gives the allowable bending stress as 207 MPa
for stainless steel, so the stress levels are acceptable
Tracker Module Design Update
Steve Virostek - LBNL Page 13
Outer Vessel Analysis (hand calc.)
The allowable external pressure for 15mm thick vessel is 1.39 MPa (>>0.1 MPa)
Details of compliance with the pressure vessel code PD 5500 need to be addressed
Tracker Module Design Update
Steve Virostek - LBNL Page 14
Magnetic Shielding FEA (gravity)
1 g load on magnetic shielding attached to vessel; fully fixed at support stand base
Max stress: 17.4 MPa
Tracker Module Design Update
Steve Virostek - LBNL Page 15
Magnetic Shielding FEA (gravity)
1 g load on magnetic shielding attached to vessel; fully fixed at support stand base
Max deflection: 0.1mm
Tracker Module Design Update
Steve Virostek - LBNL Page 16
Magnetic Shielding FEA (gravity)
1 g load on magnetic shielding attached to vessel; fully fixed at support stand base
Max deflection in Y: 0.09mm
Tracker Module Design Update
Steve Virostek - LBNL Page 17
Magnetic Shielding FEA (axial load)
50 ton axial load on magnetic shielding w/vessel; fully fixed at support stand base
Max stress: 315 MPa
Max bending stress: 315 MPa
Tracker Module Design Update
Steve Virostek - LBNL Page 18
Magnetic Shielding FEA (axial load)
50 ton axial load on magnetic shielding w/vessel; fully fixed at support stand base
Max deflection: 2.5mm Further input needed on actual shielding load
Tracker Module Design Update
Steve Virostek - LBNL Page 19
Vacuum Pumping Issues
Standard cryo pumps can be affected by magnetic fields•CryoTorr 8 (Helix Technology Corp.) is limited to 200 gauss•The cold head motor can seize at higher fields•Current MICE layout includes pumps in high field locations
Mitigation strategies: move pumps out of high fields or add local shielding
•Moving pumps reduces conductance and effective pumping speed
•Local shielding can unacceptably perturb the magnetic field•Likely solution is a combination of pump relocation and
shielding
Further work will be required to develop an optimal solution•Calculation of pumping effectiveness as a function of location •Determination of magnetic field strength as a function of
location •Analysis of the effects of shielding material on the magnetic
fields•Exploration the availability of pumps less sensitive to magnetic
fields
Tracker Module Design Update
Steve Virostek - LBNL Page 20
Tracker Module Design Summary
•Recent modifications to design and 3D model include new coil geometry, increase in outer vessel diameter, revised support stand design and redesigned magnetic shielding support
•Separate analyses of the outer vacuum vessel, inner tube and end plates, module support stand and magnetic shielding support with vacuum, magnetic and gravity loading are done
•Upcoming tasks include radiation shutter integration with the 3D model, development of a full FEA model under combined loading and a vacuum system/field analysis (all MICE modules)
•Development of a detailed specification for obtaining bids for procurement of the tracker solenoid module is under way