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Developing MACS

Developing MACS. A Third Generation Cold Neutron Spectrometer. What is MACS?.

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Developing MACS

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  1. Developing MACS A Third Generation Cold Neutron Spectrometer Timothy D. Pike

  2. What is MACS? MACS is a Multi Axis Crystal Spectrometer that is under development at the NIST Center for Neutron Research. This third generation cold neutron spectrometer will provide ultra high sensitivity access to dynamic correlations in condensed matter on length scales from 0.1 nm to 50 nm and energy scales from 0.05 meV to 20 meV. The project is funded jointly by the NIST Center for Neutron Research, the National Science Foundation, and the Johns Hopkins University and will be complete in the fall of 2006. This talk will discuss the state of the design as a snapshot of the overall instrument development process. Professor Collin Broholm Johns Hopkins University Timothy D. Pike

  3. Scientific Program and Requirements • What type of Spectrometer is MACS? • Which experiments is it good for? • Specifications to MACS-imize science output Timothy D. Pike

  4. Goals in Neutron Spectroscopy • A central tool in condensed matter physics • Unique information about dynamic correlations • Model independent access to interaction strength • Access microscopic structure of dynamic systems • Limited scope on current instruments • Need cm3 sized crystals • Need weeks of beam time • Need to be neutron scattering expert • Increased sensitivity will broaden impact • Smaller samples earlier in new materials cycle • Impact in a wider range of science • Parametric studies • Comprehensive surveys for tests of theory Timothy D. Pike

  5. Overall Requirements for MACS • Maximize sensitivity • Maximize flux on sample dE≈0.2 meV, dQ≈0.1Å-1 • Maximize detection solid angle at fixed Ef • Minimize background • Optimize performance for users • Robust and reliable soft- and hard-ware • Standardized dynamic “finger prints” of sample • Versatility cannot compromise basic mode • Streamline experimental process • Start Commissioning in 3 years from now Timothy D. Pike

  6. MACS Beam Increase brightness at fixed neutron production New cold source installed in 2002 has increased flux by 1.8 Timothy D. Pike

  7. 21 channel crystal analyzer Translating MACS Monochromator Two Radial Collimators that Control energy resolution Variable aperture that controls Q-resolution Beam Shutter super mirror guide channel Cooled Be, PG, and Al2O3 Overview of MACS Timothy D. Pike Design by T. D. Pike and C. Brocker

  8. Incident beam filters • PG filter (8 cm) • Order suppression at 13.7 meV and 14.7 meV • Fast neutron suppression E<15 meV • Be filter (10 cm) • Order suppression E<5 meV • Fast neutron suppression E<5 meV • Sapphire filter (8 cm) • Fast neutron suppression 15<E<20 meV Timothy D. Pike

  9. LA A LA B B A Collimators in series Timothy D. Pike

  10. Smee et al. (2002) 5 cm f=4 m 1428 cm2 PG Timothy D. Pike

  11. Incident Beam Line • Shielding Design of Incident Beam Portion of the Instrument:MACS General Layout, MACS Monte Carlo • Beam Tube Design • Shutter Design • Cryo Filter Exchanger (CFX) • In-Line Collimator Exchanger (ICX) • Variable Beam Aperture (VBA) • Super-mirror Guide (SMG) Timothy D. Pike

  12. MACS General Layoutv.1 Plan View Drawing Courtesy of S. Smee Timothy D. Pike

  13. MACS General Layoutv.3 Plan View 2 Timothy D. Pike

  14. MACS General LayoutOptimization Timothy D. Pike

  15. MACS Monte CarloBeam Optimization (Radius SMG) Timothy D. Pike

  16. MACS General LayoutC-100 Perspective 1 Timothy D. Pike

  17. MACS General LayoutC-100 Perspective 2 Timothy D. Pike

  18. MACS General LayoutMACS Perspective Timothy D. Pike

  19. MACS ShutterPlan View Timothy D. Pike

  20. MACS Shutter Calculation Results Excel Spreadsheet Courtesy of C. Brocker Timothy D. Pike

  21. MACS Shutter Perspective Timothy D. Pike

  22. Cryo Filter Exchanger (CFX)Plan View Reference Timothy D. Pike

  23. Cryo Filter Exchanger (CFX)Perspective Complete Assembly Cut-Away View Timothy D. Pike

  24. In-Line Collimator Exchanger (ICX)Plan View Reference Timothy D. Pike

  25. In-Line Collimator Exchanger (ICX)Perspective 1 Timothy D. Pike

  26. In-Line Collimator ExchangerPerspective 2 Timothy D. Pike

  27. Variable Beam Aperture (VBA)Plan View Reference Timothy D. Pike

  28. Variable Beam AperturePerspective Timothy D. Pike

  29. Super-mirror Guide (SMG)Plan View Reference 1 Timothy D. Pike

  30. Super-mirror Guide (SMG)Plan View Reference 2 Timothy D. Pike

  31. Super-mirror Guide (SMG)Perspective 1 Timothy D. Pike

  32. Detector • Detection System Shielding • Detector System Motion Control • Post Sample Filter Exchanger • Post Sample Collimator Exchanger • Double Crystal Analyzer Linkage Timothy D. Pike

  33. Twenty-one Channel Analyzer System Design by C. Brocker Timothy D. Pike

  34. “TAS” detector Collimator 1 Energy integrating Detector 8o vertically focusing Analyzer crystals BeO filter Be filter PG filter Collimator 2 Design by C. Brocker

  35. Detector ShieldingPlan View 1 Timothy D. Pike

  36. Detector ShieldingPlan View 2 Timothy D. Pike

  37. Detector ShieldingPerspective Timothy D. Pike

  38. Detector Shielding Multiple SegmentsPerspective 2 Timothy D. Pike

  39. Detector Shielding Segment ConstructionPerspective 1 Timothy D. Pike

  40. Detector System Motion ControlPerspective Timothy D. Pike

  41. Detector System Motion ControlPlan View Timothy D. Pike

  42. Post Sample Cryo Filter ExchangerPerspective Views Illustrations Courtesy of JHU IDG Timothy D. Pike

  43. Double Crystal Analyzer Linkage • Engineering Challenges • Design Approach • Optimization • What’s Next? Precision Mechanism with 2 Theta Output Adaptation of Golovchenko Mechanism Shielding, Tolerances Life testing, Accuracy Testing, Neutron Beam Testing Timothy D. Pike

  44. Monochromator Concept BasisFigures 1 & 2 Repeated Timothy D. Pike

  45. Double Crystal Analyzer Linkage Prototype Perspective 1 Timothy D. Pike

  46. Double Crystal Analyzer Linkage Prototype Perspective 2 Timothy D. Pike

  47. Double Crystal Analyzer Linkage Prototype Perspective 3 Timothy D. Pike

  48. Double Crystal Analyzer Linkage Prototype Perspective 4 Timothy D. Pike

  49. MACS General LayoutC-100 Perspective 2 Timothy D. Pike

  50. MACS General LayoutC-100 Perspective 3 Timothy D. Pike

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