tracker solenoid module design update steve virostekstephanie yang mike greenwing lau lawrence...

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

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 3D Model

Magnetic shielding

Cold mass supports

Radiation shutter

Steel tube supports

Cryocooler port

Magnetic shieldingsupports

Coil lead feedthrough

Side plates



Design of the tracker module support stand

Vessel and Stand 2D Drawing

10mm thick plate

100 x 100 x 5 box section



Iron Shielding Support Concept



Shielding Support Details



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



Vessel & Support FEA Results

50 ton, uniform axial load on vessel; fully fixed at support stand base

Max stress: <100 MPa



Vessel & Support FEA Results

50 ton, uniform axial load on vessel; fully fixed at support stand base

Max deflection: 1mm



End Plate & Inner Tube FEA

0.1 MPa external pressure; outer edges of end plates are fixed

Max stress: 128 MPa



End Plate & Inner Tube FEA

0.1 MPa external pressure; outer edges of end plates are fixed

Max deflection: 0.7 mm



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



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



Magnetic Shielding FEA (gravity)

1 g load on magnetic shielding attached to vessel; fully fixed at support stand base

Max stress: 17.4 MPa





Max deflection: 0.1mm





Max deflection in Y: 0.09mm



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



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



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 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

tracker solenoid module design update steve virostekstephanie yang mike greenwing lau lawrence...

Documents

tracker module outer

updated module design

tracker solenoid module

vessel support fea results

shielding support details

magnetic shielding fea

baseline design

thick vessel