Neutron Scattering Upgrades at the High Flux Isotope Reactor

Neutron Scattering Upgrades at the

High Flux Isotope Reactor

James B. RobertoAssociate Laboratory DirectorOak Ridge National Laboratory

presentation toBasic Energy Sciences Advisory Committee

Gaithersburg, Maryland

July 22, 2002

OAK RIDGE NATIONAL LABORATORYU.S. DEPARTMENT OF ENERGY

Outline HFIR update Neutron scattering

upgrades Beam lines and

shielding Cold source New and upgraded

instruments User program


A major refurbishment has been completed at HFIR• New reflector, cage, and

shroud installed

• New cooling tower completed

• New process waste line installed

• Larger beam tubes fabricated and installed

• Improvements to electrical, mechanical, and control systems

• SAR and TSR updates completed and approved

• Operational Readiness Review completed

• Operations resumed in December 2001

New cooling tower

Installing the new reflector


Neutron scattering upgrades

New guide hall

New and upgraded instruments

Cold source intensity comparable to the world’s best

Increased thermal neutron intensities

Formal user program (same as SNS)

The upgraded HFIR will include 15 state-of-the-art instruments on some of the world’s most intense steady-state neutron beams


Beam lines and shielding

Larger beam tubes for increased intensity using vertical focusing

Shielding tunnel at HB-2 to support multiple beams/instruments

New shutter assemblies and monochromator drums to support larger, more intense beams

New HB-2 beam tube with beryllium inserts

New monochromator drum


Beam tube installation


Installation of the HB-2 shielding tunnel

Shield blocks

Shutter assembly


Cold source update Refrigerator plant

completed Moderator vessel

completed Neutron guides in

fabrication New instruments

(SANS I & II) in fabrication

SANS hall under construction (includes increased user support space)

The HFIR cold source will have a brightness comparable to the best in the world


Refrigerator

Guide Hall

Compressors

Cold-source moderator vessel

Cold neutron guide

Cold source and guide systems


Instrument suite after upgrades

Improved optics, monochromators,and software

Thermal neutron intensities increased 2-10 times at sample position

Cold neutron intensities increased 100 times for SANS

New guide hall with expanded user support space

Thermal Instruments

Polarized triple-axisspectrometer

Fixed energy triple-axisspectrometer

Powder diffractometer

Residual stress diffractometer

Wide angle neutron diffractometer (U.S./Japan)

Triple-axis spectrometer

Triple-axis spectrometer

Four-circle diffractometer

HB-1

HB-1A

HB-2A

HB-2B

HB-2C

HB-2D

HB-3

HB-3A

Cold triple-axis spectrometer*

40-m high-resolution SANS

35-m biology SANS

USANS

Reflectometer

Cold triple-axisspectrometer (U.S./Japan)

SNS optics test station

CG-1

CG-2

CG-3

CG-4A

CG-4B

CG-4C

CG-4D

*Proposed

Cold Instruments


Thermal neutron triple-axis spectrometers HB1A: Ames/ORNL (installation in October)

Fixed incident energy at 14.7 meV World class for magnetic structures

HB1: Installed, running in commissioning mode Standard or fully polarized mode Excellent for magnetic excitations, magnetic structure,

and phonons World class for polarized inelastic studies

HB2: Installation Spring 2003 High-intensity thermal beams for incident

energies up to 45 meV World class for medium energy excitations

in small or weakly scattering samples HB3: Installation in October

Versatile thermal instrument for unpolarized measurements

World class for medium- and high-resolution inelastic scattering at thermal energies

HB-1 schematic


HB-1 triple-axis spectrometer upgrade

Installed and operating in commissioning mode

New monochromator drum and instrument shutter

New software, display, motor configuration, and analyzer wedge system

New vertically-focused monochromator

Typical intensities at sample 3 times higher

Similar improvements at HB-2 and HB-3


HB-3 triple-axis spectrometer staged for installation


Neutron powder diffractometer upgrade

New software, diffractometer control, and sample environments Factor of 10 performance improvement for most experiments World class for structural studies, magnetic structures, texture

and phase analysis

Addition of 12 new detectors, bringing total to 44

Vertically focusing monochromator using individually-deformed Ge wafers


Wide angle neutron diffractometer upgrade High-intensity powder

diffractometer for time-resolved studies and diffuse scattering (U.S./Japan instrument)

New monochromator system

Detector being overhauled New instrument controls Factor of 5-10 gain in

intensity World class for single-

crystal diffuse scattering and time-resolved powder studies


Four-circle diffractometer upgrade New monochromator

(vertically focused, bent stacks of thin perfect crystals)

New diffractometer control system

New software for more efficient peak searching using 7-anode detector

Factor of 2-4 performance improvement

World class for small unit-cell crystal structural studies, particularly H-bonding


Cold-neutron triple-axis spectrometry

High-resolution measurements of excitations

Many frontier problems in condensed matter and other areas demand these instruments Highly correlated electronic

systems Quantum magnetism Molecular and nanocluster

magnetic systems Frustrated and random systems Superconductors Field dependence of excitations in a

spin-gap system


Cold triple-axis spectrometers at HFIR CG-4C: U.S./Japan spectrometer

(in progress) Cold triple-axis based on

BNL H4M instrument Vertically focusing

monochromator CG-1: STAR - Sub-thermal

Triple-Axis Research Spectrometer (proposed) Incident energies up to

25 meV Harmonics removed by

velocity selector Vertically diverging “trumpet”

guide allows enhanced vertical focusing Polarized beam measurements World class for high-resolution measurements of excitations in

single crystals – complementary to time-of-flight instruments


CG-1 (STAR) schematic

guide

Localshutter

velocityselector(l/n filter)

Collimator

Monochromator(vertically focusing)

PG/heusler/other

PG Analyzer(horizontally

focusing)

filters(Be/BeO

orpolarizer)

PSD


Calculated flux at sample position for CG-1 (STAR)STAR at various wavelengths and mosaic spreads

0.4˚

1.4•108

1.9•108

8.8•106

1.2˚

1.1•108

1.2•108

4.7•106

0.8˚

1.3•108

1.6•108

6.4•106

1.8 Å (25 meV)

3.0 Å (9 meV)

6.0 Å (2.3 meV)

Assumptions: 2C guides (horizontal & vertical), “ideal” vertical focusing, perfect peak reflectivity, incident collimation 40´. CG-1 has both high intensity and good Q resolution.

IN14 (40´ coll)

3.5•107

2.0•107

6•106

2.4 Å (14 meV)

3.0 Å (9 meV)

4.0 Å (5 meV)

6.0 Å (2.3 meV)

RITA (open)

3.5•107

2.8•107

SPINS (40´ coll)

4•106

Comparison with other instruments: NG0 calc* (Broholm)

7•107

1.2•108

7•107

8•106

* NG0 or MACS has a large double focusing monochromator with low Q resolution in this configuration


Cold neutron spectrometers for large-scale structures Cold Neutron Reflectometer (MIRROR)

Length scales 3 < L < 3000 Å and reflectivities to 5 x 10-8

World class for interface and thin-film structure and dynamics, protein adsorption and bio-film and complex fluid structure at surfaces, semiconductor and metallic multilayers, etc.

40-m High-Resolution Small Angle Neutron Scattering Spectrometer (SANS) 2-D large area (1m2) detector, ~106 Hz count rate Wavelength 5 < < 30 Å (∆ / = 5-12%) World class for high-resolution kinetic studies of phase separation in

polymer blends and metallic alloys, small (~1mm3) crystals, and new directions in soft materials (e.g., in-situ processing)

35-m Medium-Resolution (Biology) SANS (OBER) 2-D large area (1m2) detector, ~106 Hz count rate Wavelength 6 < < 30 Å (∆ / = 9-28%) World class for studies of weakly scattering bio-materials, small samples

(~1 mg), and pharmaceuticals and developmental polymers available only in small amounts


Reflectometer upgrade Moving to a cold beam line in the guide hall Factor of 10 increase in flux Factor of 10 decrease in

background 100X more sensitive

Protein adsorption and bio-film structure at surfaces Semiconductor and metallic multilayers Polymeric segregation and bio-molecular diffusion Complex fluid structure at surfaces Time evolution of these surface structures


Small Angle Neutron Scattering

Explore new directions in soft materials such as in-situ processing using a neutron beam to follow structure evolution in industrially relevant equipment (e.g., extruders, flow devices)

Study weakly scattering biological materials (cross sections 10-1-10-3 cm-1)

Use much smaller samples (1mg vs. 100mg) Pharmaceuticals and developmental

polymers available only in small amounts Biological materials, which are often difficult

to prepare in bulk Small (~1mm3) crystals of high-Tc superconductors for flux line lattice melting

Undertake kinetic studies (e.g., phase separation kinetics in polymer blends and metallic alloys)

Use polarized neutrons to explore magnetic materials, super-paramagnetism, spin-glasses, etc.

Flux increases of two orders of magnitude and larger (2.5x) area detectors will make it possible to:

SANS I and II include 1m2 2-dimensional area detectors


Comparison of SANS facilities ( = 10Å )

Pre-sample

Flightpath, L

(m)

Wavelength Range,

(%)

Collimator

Area, A

(cm2)

Flux at

Sample

105sec-1-cm-2

Normalized

to same L,

A and

ORNL

SANS 118.0 10 16 4.5 18

ILL-D11 17.0 10 16 3.0 11

ILL-D22 18.0 10 22 7.5 21


User program schedule

A few experienced users can be accommodated immediately

Planning for the formal user program is under way with SNS (written user plan being prepared)

A general call will be made in the fall (formal user program starts at the end of the calendar year)

Instruments will be phased into the user program as they are commissioned (5-6 instruments by early 2003, 10-12 in early 2004)


HFIR user program guiding principles

Reliable, predictable operation (>220 days/year at >90% schedule predictability)

World-class instrumentation Fully staffed user support Formal proposal review system with external

committees Integrated HFIR/SNS user program HFIR/SNS users group (provide input for

instrumentation and user operation)

Documents

Neutron Scattering Upgrades at the High Flux Isotope Reactor