Developing MACS A Third Generation Cold Neutron Spectrometer - PowerPoint PPT Presentation

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Developing MACS A Third Generation Cold Neutron Spectrometer February 17, 2003 Timothy D. Pike 1

MACS –a New High Intensity Cold Neutron Spectrometer at NIST 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. Professor Collin Broholm Johns Hopkins University This talk will discuss the state of the design as a snapshot of the overall instrument development process. February 17, 2003 Timothy D. Pike 2

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Scientific Program and Requirements � What type of Spectrometer is MACS? � Which experiments is it good for? � Specifications to MACS-imize science output February 17, 2003 Timothy D. Pike 3

MACS –a New High Intensity Cold Neutron Spectrometer at NIST 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 cm 3 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 February 17, 2003 Timothy D. Pike 4

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Overall Requirements for MACS � Maximize sensitivity – Maximize flux on sample δ E ≈ 0.2 meV, δ Q ≈ 0.1 Å -1 – Maximize detection solid angle at fixed E f – 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 February 17, 2003 Timothy D. Pike 5

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Increase brightness at fixed neutron production 13 2 MACS Beam ϕ = × 4 . 8 10 n/cm / s = T 45 K eff New cold source installed in 2002 has increased flux by 1.8 February 17, 2003 Timothy D. Pike 6

Overview of MACS MACS –a New High Intensity Cold Neutron Spectrometer at NIST 21 channel crystal analyzer 21 channel crystal analyzer Translating MACS Monochromator Two Radial Collimators that Variable aperture that Beam Shutter Translating MACS Monochromator Two Radial Collimators that Variable aperture that Beam Shutter Control energy resolution controls Q-resolution Control energy resolution controls Q-resolution super mirror guide channel Cooled Be, PG, and Al 2 O 3 super mirror guide channel Cooled Be, PG, and Al 2 O 3 February 17, 2003 Timothy D. Pike 7 Design by T. D. Pike and C. Brocker

MACS –a New High Intensity Cold Neutron Spectrometer at NIST 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 February 17, 2003 Timothy D. Pike 8

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Collimators in series L A d α = A Nd A L A L A d α = B B L B d α ≈ eff + L L B B B A α α = A B α + α A B February 17, 2003 Timothy D. Pike 9

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Smee et al. (2002) 5 cm f=4 m 1428 cm 2 PG February 17, 2003 Timothy D. Pike 10

MACS –a New High Intensity Cold Neutron Spectrometer at NIST 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) February 17, 2003 Timothy D. Pike 11

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout v.1 Plan View Drawing Courtesy of S. Smee February 17, 2003 Timothy D. Pike 12

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout v.3 Plan View 2 February 17, 2003 Timothy D. Pike 13

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout Optimization February 17, 2003 Timothy D. Pike 14

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS Monte Carlo Beam Optimization (Radius SMG) February 17, 2003 Timothy D. Pike 15

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout C-100 Perspective 1 February 17, 2003 Timothy D. Pike 16

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout C-100 Perspective 2 February 17, 2003 Timothy D. Pike 17

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS General Layout MACS Perspective February 17, 2003 Timothy D. Pike 18

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS Shutter Plan View February 17, 2003 Timothy D. Pike 19

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Excel Spreadsheet Courtesy of C. Brocker MACS Shutter Calculation Results February 17, 2003 Timothy D. Pike 20

MACS –a New High Intensity Cold Neutron Spectrometer at NIST MACS Shutter Perspective February 17, 2003 Timothy D. Pike 21

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Cryo Filter Exchanger (CFX) Plan View Reference February 17, 2003 Timothy D. Pike 22

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Cryo Filter Exchanger (CFX) Perspective Complete Cut-Away Assembly View February 17, 2003 Timothy D. Pike 23

MACS –a New High Intensity Cold Neutron Spectrometer at NIST In-Line Collimator Exchanger (ICX) Plan View Reference February 17, 2003 Timothy D. Pike 24

MACS –a New High Intensity Cold Neutron Spectrometer at NIST In-Line Collimator Exchanger (ICX) Perspective 1 February 17, 2003 Timothy D. Pike 25

MACS –a New High Intensity Cold Neutron Spectrometer at NIST In-Line Collimator Exchanger Perspective 2 February 17, 2003 Timothy D. Pike 26

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Variable Beam Aperture (VBA) Plan View Reference February 17, 2003 Timothy D. Pike 27

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Variable Beam Aperture Perspective February 17, 2003 Timothy D. Pike 28

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Super-mirror Guide (SMG) Plan View Reference 1 February 17, 2003 Timothy D. Pike 29

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Super-mirror Guide (SMG) Plan View Reference 2 February 17, 2003 Timothy D. Pike 30

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Super-mirror Guide (SMG) Perspective 1 February 17, 2003 Timothy D. Pike 31

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector • Detection System Shielding • Detector System Motion Control • Post Sample Filter Exchanger • Post Sample Collimator Exchanger • Double Crystal Analyzer Linkage February 17, 2003 Timothy D. Pike 32

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Twenty-one Channel Analyzer System Design by C. Brocker February 17, 2003 Timothy D. Pike 33

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

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector Shielding Plan View 1 February 17, 2003 Timothy D. Pike 35

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector Shielding Plan View 2 February 17, 2003 Timothy D. Pike 36

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector Shielding Perspective February 17, 2003 Timothy D. Pike 37

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector Shielding Multiple Segments Perspective 2 February 17, 2003 Timothy D. Pike 38

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector Shielding Segment Construction Perspective 1 February 17, 2003 Timothy D. Pike 39

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector System Motion Control Perspective February 17, 2003 Timothy D. Pike 40

MACS –a New High Intensity Cold Neutron Spectrometer at NIST Detector System Motion Control Plan View February 17, 2003 Timothy D. Pike 41