1. Examples of Mechanical Engineering at SLAC June, 2008 Martin Nordby

2. PPA Mechanical Engineering 2 My Background BS in Mechanical Engineering from Stanford –Thermosciences –Design engineering –Engineering mechanics My interests centered on the design of thermal-mechanical systems –Power generation systems –Aeronautics

3. PPA Mechanical Engineering 3 Mechanical Engineering at SLAC Generalist vs specialist engineering –Much of the mechanical engineering at SLAC requires a broad spectrum of skills –While we have some specialists who have cultivated a niche in a particular skill, most of the mechanical engineers at SLAC involve themselves in a great variety of work –Because of this broad exposure, mechanical engineers are often in the best position to manage the technical development of entire projects –This is not for everyone, and is definitely not the way many private companies operate Involvement in a broad spectrum of mechanical engineering disciplines –Design engineering –Manufacturing engineering –Materials science research –Thermal and structural analysis –Civil engineering –Specialty fields Cryogenics Vacuum systems Magnet design Radiation effects –Project engineering and technical management

4. PPA Mechanical Engineering 4 “Variety” is the Hallmark Projects range the spectrum –Group size: scientist and engineering groups can range from 2-3 up to 100’s –Complexity: simple design work to complex, multi-disciplinary system designs –Cost: $10K to $100M –Physical size: component size and weight spanning 6 orders of magnitude Materials—given the unique requirements of the experiments we develop, we design components using a wide range of materials –Conventional engineering alloys: aluminum, steel, stainless steel, copper, titanium –Specialty metals: beryllium, tungsten, molybdenum, lead, super-alloys –Engineered materials: ceramics, carbon fiber, plastics, epoxies –Other: glass, quartz Over the life of a project, the mechanical engineer’s job is to do what it takes to get the job done –Engineering design: developing CAD designs of experiments, managing designers –Engineering analysis: running FEA analysis, working with specialists –Procurement: specifying manufacturing requirements and selecting contractors –Expediter: shop-floor troubleshooting with machinists, chasing down parts –Getting your hands dirty: turning wrenches, supervising technicians On-the-job learning –Every project has been unique, with new challenges –For each, there is much to learn and new ways to apply past experiences

5. PPA Mechanical Engineering 5 SLD Detector 4000 ton structure 4 stories high Liquid argon calorimeter 600 tons of lead modules Aluminum support cylinder Operated at -200 o C

6. PPA Mechanical Engineering 6 PEP-II Positron-Electron Storage Rings High-current electromagnets High power density cooling systems Design for ultra-high vacuum (10 -10 atmospheres) Stable support systems 0.01” level alignment of ¼ mile of beamline

7. PPA Mechanical Engineering 7 PEP-II Vacuum System Q2 Septum Chamber where the two beamlines come together B1 Vacuum Chamber 12” from the interaction point

8. PPA Mechanical Engineering 8 PEP-II QD-1 Quadrupole Magnet Combined-function steering and focusing magnet The largest quadrupole permanent magnet ever made Tightly packaged to fit inside the particle detector

9. PPA Mechanical Engineering 9 PEP-II QF-2 Quadrupole Magnet Developed with Lawrence Berkeley National Lab High-powered electromagnet to focus electron beam Water-cooled

10. PPA Mechanical Engineering 10 BaBar Detector Interaction Region Cross-Section Through BaBar Detector and Interaction Region Showing beamline components and detector subsystems Low Mass Support Tube Filament-wound carbon fiber tube Supports ~2000 lbs of magnets and vacuum chamber through the BaBar detector Low mass and low density to reduce interactions with particles coming off the collision point

11. PPA Mechanical Engineering 11 GLAST Large Area Telescope Hot Case Orbit: Beta 0, +Z Zenith, +X Sun Pointing sun A particle physics detector in low earth orbit Silicon detectors to track incoming gamma rays Cesium iodide salt crystals collect and measure the energy of the gamma ray light

12. PPA Mechanical Engineering 12 LAT Structural Support and Cooling Systems 3000 kg instrument needed to stay aligned, despite 6g launch accelerations and large changes in heat load from daylight to eclipse 650 watts of power need to be dissipated by large radiator panels

13. PPA Mechanical Engineering 13 LAT Environmental Testing Tests to prove that the LAT could handle the environments it would be exposed to Vibration Acoustic Electro-magnetic interference Thermal-vacuum

14. PPA Mechanical Engineering 14 GLAST in the Launch Vehicle Fairing This was one of the largest and heaviest payloads launched by a Delta-II

15. PPA Mechanical Engineering 15 Large Synoptic Survey Telescope (LSST) Camera 3.5 giga-pixel digital camera 5 foot diameter main lens Cooled to -100 o C to reduce light noise Suspended 90 feet off the ground “Wide, fast, and deep” telescope

16. PPA Mechanical Engineering 16 LSST Camera Cryostat P atm at 8000 ft Deflection of 782 mm diam lens P atm at sea level Stresses in 782 mm diam lens CCD detectors and electronics operate at -100 o C and 10 -9 atmos. 2-½ foot L3 lens carries vacuum load

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