Positron Source Target Update Tom Piggott Jeff Gronberg Lisle Hagler Dain Holdener Marty Roeben This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W Eng-48. UCRL-PRES

Session Schedule Introduction (Piggott) - 5 mins Livermore update (Piggott) - 10 mins UK update (Bailey) - 10 mins Graphite/ liquid Pb development (Logatchov, presented by Bailey) - 5 mins Heat deposition, activation of target and capture system (Ushakov) - 30 mins Eddy current simulations (Rochford) - 10 mins Discussion - 20 mins Next Session OMD overview (Gronberg) - 20 mins OMD calculations, beam window heating (Gai) - 20 mins Lithium lens, solenoid focusing alternatives (Mikhailichenko) - 30 mins UCRL-PRES

Action Items from September Meeting Target prototype drawings (LLNL/RAL/DL) –In progress at LLNL and DL OMD forces –Presentations from RAL and ANL R&D timeline –Pending funding? Remote handling impact (RAL/DL) –Presentation in Target Hall session Alternative target materials (RAL/Liverpool) –In progress Beam window viability (ANL) –Presentation in OMD session UCRL-PRES

Current Target Design 1 m diameter, 5 spoke wheel Shaft support on both sides UCRL-PRES

Shaft Support on Both Sides Eliminates need for belt drive on motor Allows use of standard water union Requires two intrusions into vacuum space Reduces deflection of target wheel UCRL-PRES

Rotordynamic/Vibration Calculations Work was done for a four spoke, 2 m diameter wheel Rotordynamic analysis Structural/ vibrational mode analysis Vibrational mode study suggested possible issue near operating point, so shift to a five spoke wheel was implemented UCRL-PRES

Flywheel Critical Speeds (Two-End Support Design) 4/rev 1/rev Primary Critical Speed = 500 RPM 1 st Secondary Critical Speed = 120 RPM 2 nd Secondary Critical Speed = 170 RPM Primary Critical Speed Secondary Criticals Cylindrical Whirl Mode Forward Tilt Whirl Mode Backward Tilt Whirl Mode Support Translational Stiffness = 100,000 lbf/inSupport Rotational Stiffness = 10,000 in-lb/rad 900 RPM Operating Speed UCRL-PRES

Wheel Deformations (Two End Support) Static displacement of cantilevered design is 7.62 cm vs cm for support on both ends UCRL-PRES

Current/Future Work Redo thermal/structural calculations for 1 m wheel using energy depositions from simulations at SLAC/ANL Redo rotordynamic/ vibration calculations for 1 m wheel Working with metallurgist to address any issues from creep, fatigue, microstructure changes Incorporating results from eddy current simulations into structural and vibration calculations Continue working on prototype and experiment development UCRL-PRES