SNS Experimental FacilitiesOak Ridge Soft Condensed Matter with Spallation Neutrons JK (Jinkui) Zhao Presented at the Review Meeting of the Chinese Spallation Neutron Source August 2001, Beijing

SNS Experimental FacilitiesOak Ridge The Spallation Neutron Source

SNS Experimental FacilitiesOak Ridge SNS Construction Progress — July /arb

SNS Experimental FacilitiesOak Ridge SNS — A Multi-Lab Project Front-End: Lawrance Berkley –65-mA H - ion beam –LEBT –RFQ (2.5MeV) –MEBT Linac: Los Alamos/Jefferson –DTL ( 87 MeV ) –CCL ( 185 MeV ) –SCL ( 1Gev ) –337 m (Front End+Linac) –38mA peak H- current Ring: Brookhaven –Circumference 248m –Orbit time 945ns –Number of turns 1060 –HEBT/RTBT Target: Oak Ridge –Mercury –1.5x10 14 pp Instruments: Argonne/Oak Ridge –18 Beam ports, 6 duplexes – ~10 initial instruments 1GeV, 1.4 mA, 1.4MW 60Hz rep rate Ring: Brookhaven –Circumference 248m –Orbit time 945ns –Number of turns 1060 –HEBT/RTBT

SNS Experimental FacilitiesOak Ridge SNS Target System

SNS Experimental FacilitiesOak Ridge SNS Instrument Suit

SNS Experimental FacilitiesOak Ridge Sciences Covered by Elastic Instruments

SNS Experimental FacilitiesOak Ridge Sciences Covered by Inelastic Instruments Momentum Distributions Itinerant Magnets Crystal Fields Molecular Vibrations Lattice Vibrations Small Molecule Diffusion Large Scale Motions Polymers and Biological Systems Tunneling Spectroscopy Electron-Phonon Interactions Hydrogen Modes Molecular Reorientation Ultracold Neutrons Fundamental Physics Slower Motions Larger Objects

SNS Experimental FacilitiesOak Ridge Why Spallation – Source Point of View From Fraser et al., measurements at Brookhaven Cosmotron Higher neutron yield mercury : 1 proton  15 neutrons Intrinsically safer 1995 Good News - The American stops the ANS project 2000 Responsible Neutron Research The Green stands behind the European Spallation Neutron Source

SNS Experimental FacilitiesOak Ridge Why Spallation – Instrument Point of View ms time Time Structure m 0 Distance  = 4000 / 25Hz/20m  8 Å High Peak Flux ISIS ~ 8x10 15 n/cm 2 /s 2 ILL ~ 1.5x10 15 n/cm 2 /s High Resolution (  d/d) 2 = (  ) 2 + ctan 2  *   (  t pulse /    = ————— L

SNS Experimental FacilitiesOak Ridge With ISIS and SNS, Why a 100 kW 25Hz source? kW/Hz 160/ /60 100/25 Status Exists Under Construction Proposal Performance Current Best Future Best ??????? Challenge R&D Required Mature Technology Cost ~ ¥ 11.2 B (US $1.4B) ~ ¥ 800M Bandwidth Narrow Narrow Wide (2X) Target Solid Liquid Metal Solid (1.25X) Moderator LH2/L-Methane L-Hydrogen Solid Methane (3.5X) Slab moderator(2X) ISIS SNS CSNS (from LWTS study) Summary CSNS will outperform ISIS To SNS: — High-Resolution: 3-4X neutron production gain » CSNS  ¼ SNS — Long wavelength: 8 X gain, 2X bandwidth » CSNS  SNS — At 7% of the costs!

SNS Experimental FacilitiesOak Ridge Soft Condensed Matter Proteins, DNABlock CopolymersMicelles, Liposomes Complex Fluids Aerosols Thin Films and Membranes

SNS Experimental FacilitiesOak Ridge The ISIS Fan

SNS Experimental FacilitiesOak Ridge SNS Instruments for Soft Condensed Matter Extended Q-Range SANS Liquid Reflectormeter Disordered Materials Protein Crystalography Back Scattering Multi Chopper Spin-echo spectrometer Elastic - DiffractormetersInelastic – Spectrometers

SNS Experimental FacilitiesOak Ridge Extended-Q SANS

SNS Experimental FacilitiesOak Ridge Extended-Q SANS

SNS Experimental FacilitiesOak Ridge Extended-Q SANS Performance – Flux

SNS Experimental FacilitiesOak Ridge Extended-Q SANS Performance – Q range EQ- SANS Q = – 10 Å -1 ( 4 decades !!! ) Reactor SANS Q = – 0.5 Å -1 (< 3 decades)  One order of magnitude higher in Q-coverage

SNS Experimental FacilitiesOak Ridge Extended-Q SANS Performance – Simulations

SNS Experimental FacilitiesOak Ridge Liquid Reflectomer Ankner & Klose

SNS Experimental FacilitiesOak Ridge Liquid Reflectomer POSY-II MURR ADAM, NG-1 SURF SNS reflectometers will accumulate specular reflectivity data times faster than the best existing instruments. Improved Q max will yield near-atomic-scale layer-thickness sensitivity. Simulated data from 10-Å SiO 2 layer atop Si. SNS-L utilizes 12 incident angles  i to measure Q max > 0.9 Å -1 in  t < 5 hours (18,000 s). Arrows indicate reflectivities measured in hours (40-80,000 s) by existing instruments.  i  t i (s)

SNS Experimental FacilitiesOak Ridge Membrane Proteins ~30% proteins are membrane proteins Difficult to crystallize Difficult to study by NMR For in situ studies, proteins and lipids have different length scales  Needs large Q-coverage

SNS Experimental FacilitiesOak Ridge Interaction and organization of a membrane protein From Huey Huang, Rice University SANS (NIST) at 37°Cat 15-20°C The protein is an important antibiotic protein. It apparently crystallized at 15-20°C. There may be more diffraction spots outside the detector. Need Larger Q-range, better resolution instrument! Protein-membrane interaction by X-ray. Both very low Q and very high Q are needed. Neutron with contrast variation is desirable protein lipid(solvent)

SNS Experimental FacilitiesOak Ridge Q range - Performance Impossible experiments on Reactor-based SANS become possible on Spallation Sources  New Sciences

SNS Experimental FacilitiesOak Ridge Structure Based Drug Design AIDS Arthritis and Inflammation Cancer Diabetes Mellitis Heart Diseases Parkinson's Disease Sleeping Sickness Immune Diseases Antivirals Novel Methodologies

SNS Experimental FacilitiesOak Ridge Protein Structure, Hydrogens, Water Half the atoms in proteins are hydrogens Proteins have many bound waters Hydrogens at the active site of proteins are critical Neutrons are best suited for locating hydrogens!! Water on monoxymyoglobin Cheng and Schoenborn, Acta. Cryst. 1990

SNS Experimental FacilitiesOak Ridge HIV Protease Inhibitor From Dealwis/Magid University of Tennessee

SNS Experimental FacilitiesOak Ridge Neutron Protein Crystallography at Reactors Flux limited On reactors, Laue method has to be used. Current best: LADI at ILL Laue drawbacks: — Peak overlaps for large molecules — Large incoherent background from hydrogen

SNS Experimental FacilitiesOak Ridge Potential Peak Overlap in Laue Pattern Kalb et al, JAC, 34, Rubredoxin Niimura- Jaeri

SNS Experimental FacilitiesOak Ridge Neutron Protein Crystallography at Spallation Sources Broader band  higher flux Lower back ground No peak overlaps Under commision: Los Alamos (similar to ISIS) Expected to outperform LADI in many areas A protein diffractometer is under planning at SNS It will reduces data collection time by ~10X It will makes possible to study larger molecules Los Alamos A protein diffractometer at CSNS will be comparable the SNS

SNS Experimental FacilitiesOak Ridge Trends in Neutron Sciences - A Few Observations More complex samples - multi-component, multi length scale Real-time studies, reactions Smaller, dilute samples Broader Q and E coverage In all these aspects, spallation sources WIN!