SNS Experimental FacilitiesOak Ridge X0000910/arb Neutron Instruments for Materials Research T.E. Mason Experimental Facilities Division Spallation Neutron

SNS Experimental Facilities Oak RidgeX0000910/arb

Neutron Instruments for Materials Research

T.E. Mason

Experimental Facilities Division

Spallation Neutron SourceAcknowledgements: Doug Abernathy, John Ankner, Ken Herwig, Frank Klose, Jinkui Zhao, Xun-Li Wang


2

A Brief Aside on What You Actually Measure:

98-6249 uc/rra


3

Neutron Scattering Cross-Section

98-6250 uc/rra


4

CW vs Pulsed Instrumentation

• In general continuous sources work with fixed wavelengths (, all t) and pulsed sources work with a wavelength band (t, all – using time and distance to determine velocities and hence wavelengths)

• If the useful wavelength band is dispersed over the full time between pulses then the pulsed instrument counts useful neutrons all of the time and the figure of merit is the peak flux

• If the full time between pulses is not useful then the figure of merit is reduced by the duty cycle

• For fixed wavelengths, counting continuously the integrated flux is the figure of merit

• Variations (e.g. pulsed instrument at CW source) can, and do exist


5

Example – Reactor - SANS

As an example consider the static approximation in ahomogeneous system:

Fourier transform of scattering length density for an object

98-6259 uc/rra


6

cAMP-Dependent Protein Kinase (PKA)Combining Neutrons with X-rays

•PKA catalyzes a variety of cellular activities, ranging from gene induction to color change in pigment cells.•PKA serves as the prototype for a class of enzymes which catalyzes protein phosphorylation, the major mechanism of cellular regulation.•The combination of neutron studies and x-ray structures of PKA subunits has provided insights into the quaternary structure of PKA, which is key to the understanding of PKA function.


7

• RC with deuterated R-subunit

• PKA (R2C2) with deuterated R-subunits

• Free C and Truncated R with x-ray

Neutron Contrast Data of PKA and RC


8

Momentum Resolution

98-6252 uc/trh


9

Having Made Some Neutrons WeWant A Monochromatic Beam!

98-6253 uc/trh


10

Pinhole SANS

• NIST/NSF 30 m SANS

• NG-3 cold neutron guide

• 20 MW reactor, hydrogen cold source


11

NIST SANSCharacteristics and Performance

• Source: neutron guide (NG-3), 60 mm x 60 mm • Monochromator: mechanical velocity selector with variable speed and

pitch • Wavelength Range: 0.5 nm-2.0 nm • Wavelength Resolution: 9%-30% (FWHM) • Source-to-Sample Dist.: 4 m to 16 m in steps via insertion of neutron

guide sections • Sample-to-Detector Dist.: 1.3 m to 13 m • Collimation: circular pinhole collimation • Sample Size: 0 to 25 mm diam • Q-Range: 0.015 nm-1 to 6 nm-1 • Detector: 650 mm x 650 mm 3He position-sensitive proportional

counter (10mm resol.)


12

• excitations characterized by ´´(Q,) a measure of absorption at (Q,).

• neutron scattering measures:S(Q,) ~ ´´(Q,) [n()+1].

• note: Q 0, recover uniform susceptibility.

• the proportionality constant involves magnetic moment direction and form factor.

Neutron Scattering and Spin Fluctuations

B ( , )Q

neutroninduces

transi tion

),(2

1),(

QQ

d


13

o(Q,) for Metals

• Excitations are electron-hole pairs

• Lindhard susceptibility:

• As T 0 states near F dominate

• Note: NMR relaxation rate:

),(~

1

0,1

Q

QQ

fTT

o

B p q p

p q ppN

f f

i( , )

( ) ( )

( )Q

2 2

( , )Q

k

h-


14

Normal State Energy Dependence

• As the frequency is increased the peaks become less well defined.

• The response is qualitatively quite similar to that of the spin density wave system Cr, above TN.


15

Example – Reactor –Triple Axis

• RITA (Re-Invented Triple Axis) at Risø, DR-3 Denmark

• 10 MW reactor, supercritical hydrogen cold source


16

Having Made Some Neutrons WeWant A Monochromatic Beam!

98-6254 uc/trh


17

For Inelastic Scattering You AlsoNeed Energy Analysis

98-6256 uc/rra


18

Crystal Monochromator (continued)

98-6255 uc/trh


19

Triple-Axis Spectrometer Resolution

• There are analytical methods for calculating the resolution (Cooper + Nathans, Nielsen + Bjerrum-Møller, Popovici)

• These are obtained from the program RESCAL forcollimation 60'– 60'– 60' – 60'30' PG002 monochromator and analyzer10' sample mosaicEf = 5meV ( = 4.04 Å)h = 0 q = 1 Å-1

98-6258 uc/rra


20

Incident Beam Optics

• Supermirror guide in front of the monochromator increases flux• Sapphire filter reduces gamma and fast neutron background and

protects guide• Velocity selector in front of monochromator remove higher order


21

Effect of the Guide


22

Secondary Spectrometer

• Area detector and analyser crystal array permits flexible focussing


23

SPINS at NIST

• A similar (on the back end) instrument is SPINS at NIST


24

Time-of-Flight Inelastic Instruments

• Two basic types – direct geometry – fixed Ei (e.g. HET chopper)

– Indirect geometry – fixed Ef (e.g. IRIS backscattering)


25

Chopper Spectrometers

• Operate in the thermal to epithermal energy range – 5 meV < Ei < 1000 meV

• Use fast, magnetic bearing Fermi choppers to select E i

• Maximal Q range with continuous coverage to large scattering angles– Need room at least on one side for scattering chamber

Consider two choppers should be placed on the bottom upstream moderator at end positions - BL9 & BL18 at SNS


26

Target Layout

X = 5 m

X = 6.5 m

BL18

BL17

BL9


27

Geometric constraints

X m

2

LiLf

BL18: X = 5 m m = 35°

For 2 >125° & Lf = 2.5 m , Li =13.0 m

For 2 = 60° & Lf = 6.0 m , Li =13.1 m

BL9: X = 6.5 m m = 35°

For 2 >125° & Lf = 2.5 m , Li =15.7 m

For 2 = 60° & Lf = 6.0 m , Li =15.8 m

m fm i 2sinLsinL X

Accessible regions in Lf lie below a straight line in (Li,Lf) plane


28

Flux on sample at 200meV - 5% elastic resolution

Optimum flux not accessible for any L3

BL18 Constrained 5% elastic resolution

0.0E+00

1.0E+05

2.0E+05

3.0E+05

4.0E+05

5.0E+05

6.0E+05

7.0E+05

0 10 20 30 40 50 60

Source-Sample distance (m)

Flu

x o

n s

amp

le (

n/c

m2/s

)

1000meV

200meV

50meV


29

Flux on sample at 200meV - 1% elastic resolution

Can optimize flux for a given L3 that is not too large

BL18 1% elastic resolution

0.0E+00

1.0E+04

2.0E+04

3.0E+04

4.0E+04

5.0E+04

6.0E+04

7.0E+04

8.0E+04

9.0E+04

1.0E+05

0 10 20 30 40

Source-Sample distance (m)

Flu

x o

n s

amp

le (

n/c

m2/s

)

L3 = 6m

L3 = 5m

L3 = 4m


30

Proposed two spectrometer layout

T0

E0

Pit Area

Sample

Beamstop

Detectors

BL17 - “high resolution”

BL18 - “high flux”


33

Instrument parameters

Spectrometer High Flux High Resolution

Ambient H2O decoupled poisoned 18BU 100mm(H) x 120mm(V)Moderator anddimensionsAngle 13.75 (possible 27.5 ) 0 (possible 13.75 )GeometrySource-chopper (L1)Chopper-sample (L2)Sample-detector (L3)

12.0m1.5m2.5m

15.5m2m6m

ChoppersT0 horizontal axisT0 vertical axisE0 (Fermi) vertical axis

Mechanical 60 Hz @ 7.0m(Magnetic 300 Hz @ 7.5m)Magnetic 600 Hz @ 12.0m

Mechanical 60 Hz @ 9.0mMagnetic 300 Hz @ 10.0mMagnetic 600 Hz @ 15.5m

GuideTypeLength

Tapered supermirror 3c

~7mTapered supermirror 3c

~11m

Apertures and collimatorsAfter E0 (Fermi) chopper

2 VariableSoller collimator

3 VariableSoller collimator

Max. sample size 50mm(H) x 75mm(V) 50mm(H) x 75mm(V)


34

Instrument parameters

Spectrometer High Flux High Resolution

Scattering/samplechamberRadius sample-detectorHeightVacuum at sampleVacuum flightpathCollimationShielding, innerShielding, outer

2.5m2.5m< 10-6 torr< 10-2 torrOscillating radial collimatorB4C, 50m2

~0.5 m (TBD) thick, 100m2

6m6m< 10-6 torr< 10-2 torrOscillating radial collimatorB4C, 150m2

~0.5 m (TBD) thick, 250m2

Linear PSDsNumberTypeDiameterLengthResolutionTotal pixelsAngular range, horizontal

Vertical, low bank Vertical, high bankLow bank solid angle/areaHigh bank solid angle/areaTotal area

5403He 10 atm25mm900mm25mm50,400-45 to -3 , 3 -150

30

2.15 sr / 13.5 m2

13.5 m2

12003He 10 atm25mm900mm25mm50,400-30 to -2 , 2 -30 (low), 30 -60 (high) 30 100.70 sr / 26 m20.12 sr / 4 m230 m2


35

Resolution and flux calculations

0.0E+00

1.0E+05

2.0E+05

3.0E+05

4.0E+05

5.0E+05

6.0E+05

7.0E+05

8.0E+05

0 1 2 3 4 5

Elastic resolution (%)

Flu

x o

n s

amp

le (

n/c

m2/s

)

1000meV High Flux 50meV High Flux1000meV High Res 50meV High Res


36

Resolution and flux calculations

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1 10 100 1000 10000

Energy (meV)

Flu

x o

n s

amp

le (

n/c

m2 /s

)

High Flux 3.0%

High Res 1.4%


37

Q- space accessible with proposed spectrometers

Q (Å-1)0.01 0.1 1 10 100

(

meV

)

10-3

10-2

10-1

100

101

102

103

104

d (Å)0.1110100

2eV crystal analyzer

10-100eV multichopper1% high-resolution chopper3% high-flux chopper


38

Comparison to current chopper spectrometers

Instrument L1 (m) L2 (m) L3 (m) Moderator,Tilt

% energyresolution

AngularRange(Hor)

DetectorSolidAngle (sr)

LRMECSANL

6.2 0.8 2.5 CH4 2.5 – 7 % 3 - 120 0.3

HRMECSANL

12.7 1.1 4 CH4 2 – 4 % 3 - 140 0.5

HETISIS

10 1.8 2.5/4 H2O, 27 2 – 4 %3 - 30110 - 135

0.1

MARIISIS

10 1.7 4 CH4, 13 1 – 3 % 3 - 132 0.1

MAPSISIS

10 2 6 H2O, 14 1 – 3 % 3 - 60 0.45

PHAROSLANSCE

18 2 4 H2O , 15 1.5 - 3% 1 - 140 0.65

PHOENIX ISIS(HET upgrade)

12 1.8 2.5 H2O, 27 2 – 4 % 3 - 150 3.1

SNSHigh flux

12 1.5 2.5 H2O, 14 2 – 4 % 3 - 150 2.15

SNSHigh res.

15.5 2 6 H2O, 0 1 – 1.5 % 2 - 60 0.82


39

High Resolution Backscattering Spectrometer

• Performance gains over comparable reactor backscattering instruments >100 (depending on bandwidth needed)

• High-Q option (with Si 311) 500x IN13 and 18x IRIS (with 3 times Q range and better resolution!)

• Crystal analyzer (Si) with 84 m incident flight path

• Achieves 2.2 eV resolution at the elastic position with

250 eV bandwidth

• Can operate up to 18 meV energy transfer with 10 eV resolution

• Unprecedented capabilities

2000-03452/arb


40

Instrument Resolution and Q- Range

(meV)

0 5 10 15

Q (

Å-1

)

0

1

2

3

4

(meV)

0 5 10 15

f

whm

( e

V)

0

5

10

15

20

25

• Elastic Resolution 2.2 eV (fwhm)


41

supermirror funnel

detector for top analyzer

detector forbottom analyzer

beam stop

top analyzerbottom analyzer

evacuatedsample chamber

scattering vessel

Scattering Chamber


42

Guide Design

• 84 m total flight path moderator face to sample

• Curved guide– radius of curvature 4.325 km

– 10 cm horizontal x 12 cm vertical

– Natural Ni (outer radius horizontal needs higher index)

– begins 1 m from moderator face

• Supermirror funnel, ends 30 cm from sample– horizontal, 3 x c for Ni, 10 cm to 3 cm over 5 m

– vertical, 4 x c for Ni, 12 cm to 3 cm over 6 m

• Gains– 1200; = 6.3 Å

– 400; = 3.2 Å


43

39

Shutter and Core Insert Regionsfor the Standard Shutters

Distance from Moderator (m)

0 1 2 3 4 5 6 7

Rel

ativ

e G

ain

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

2.2

= 6.3 Å

= 15 Å


44

Major Spectrometer Components

• Source/Moderator decoupled, supercritical poisoned H2, TU

• Incident flight path - 84 m moderator face to sample position

• Chopper System - 3 bandwidth/frame overlap choppers

• Sample - dimensions 3 x 3 cm2

• Analyzer crystals, Bragg angle = 88 deg– Si (111): = 6.267 Å, 2.9 ster, 26 m2, d/d ~ 3.5 10-4

– Si (311): = 3.273 Å, 1.45 ster, 13 m2, d/d ~ 4.0 10-4

• Final flight path - 3 m sample-analyzer, 2.5 m analyzer-detector

• Detectors– Backscattering for diffraction

– ~ 7040 cm2 PSD 1 x 1 cm2 spatial resolution


45

Melittin in Alkanethiol/Phospholipid Hybrid Bilayer Membranes - NIST


46

Melittin in Alkanethiol/Phospholipid Hybrid Bilayer Membranes - NIST


47

NG1 Reflectometer: Polarized Beam - NIST

0.0 0.1 0.2 0.3 0.4 0.510-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

Neutron Reflectivity and 2-Layer Fitof 10nm. SiO2 Film on Si

Log (

Ref

lect

ivit

y)

Q[A-1] 0 5 10 15 20 25

0

1x10-4

2x10-4

3x10-4

4x10-4

SiO2

Si

Nb

[n

m -2 ]

Depth [nm]


48

MBE Chamber for In-situ Neutron Scattering on the NG1 Reflectometer

UHV Techniques Protective Environment

Epitaxial Thin Film Growth

Gas Loading (e.g. H)

Sputter Etching of Surface Material

RHEED Analysis

Mass Spectrometry

Scattering TechniquesSpecular Reflectometry

Off-Specular Scattering

Grazing Angle Diffraction

High Angle Diffraction

SANS

PhenomenaAdsorption / Desorption

Diffusion

Segregation

Morphology

Crystallography

Magnetism

Superconductivity

Joe Dura NIST-NCR


49

Reflectometry

• In addition to providing a unique probe for magnetic surfaces and multi-layers polarized neutrons permit direct inversion to obtain the scattering length density profile - no phase problem– a magnetic reference layer buried in the substrate can have

magnetization wrt neutron polarization varied

– for a weak absorbtion probe (valid for the neutron) three known references lead to unique solution

– drawback is the price paid in sensitivity for polarized beam

• Off-specular reflection for in-plane structure


50

SNS Reflectometers

• 2 reflectometers sharing a single beamport

• Requires new multi-channel shutters in the target station

• Allows for both vertical sample (magnetism) and horizontal sample (liquids) studies

• Novel beam bender optics allows multiplexing and reduces background

• Reflectivities <10-9, 10-50 times faster than any existing instrument

2000-03451/arb


51

Instrument features

• Views coupled 20-K H2 moderator from beamline 4TD

• Shares beamline with magnetism reflectometer

• Multi-channel beam bender eliminates all < 1.5 Å

• Three bandwidth choppers allow clean operation in 0.5-4.5, 5-9, or 9.5-13.5 Å wavelength frames

• Tapered guide delivers angular bandwidth that can be sampled by slits at 0 < < 7° relative to the horizontal

• 1-mm2-resolution PSD permits study of off-specular and grazing-incident small-angle scattering

• For liquid samples 0 < Q < 0.5 Å-1 is accessible; by tilting a solid surface, 0 < Q < 1.0 Å-1 (Rmin ~ 4×10-10)


52

Schematic

SourceMicroguide

BenderTaperedGuide Slits

Detector

14.5 m

Bandwidth Choppers

• Bender/tapered guide combination eliminates source line-of-sight

• Tapered guide delivers angular bandwidth that allows multiple angles of incidence


53

Microguide bender4c

Ni

• Bender acts as high-pass wavelength filter

• Multiple channels n transmit higher flux

[Left]: Phase-space acceptance at 5-channel bender exit for 9-Å neutrons after 0-5 bounces (red-green). [Right]: Integrated acceptance for n-channel benders.


54

Reflectometer beam benders

Bender insidewide shutterdeflects the beamdownward to a4.75° angle ontosample surface.

Sample


55

Tapered guide

Tapered guide provides angular bandwidth for liquid measurement. Slits select sample incident angle about = 4.75° centerline.

12 cm

1.75 cm

4cNi

Contours representratio of actual to maximum optical acceptance (X / Xmax)at tapered guide exit.


56

Slits

= 2.06°; = 0.0014;X / Xmax = 0.89; mavg = 3.3

= 4.75°; = 0.0061;X / Xmax = 0.86; mavg = 1.3

Slit settings off the = 4.75° centerline exhibit higher averagenumber of bounces mavg. Judicious selection of incident angle ensures optimal acceptance X.


57

Liquids reflectometer


58

1.E-111.E-101.E-091.E-081.E-071.E-061.E-051.E-041.E-031.E-021.E-01

1.E+00

0.00 0.25 0.50 0.75 1.00

Q (Å-1)

R

0.20° 1

0.30° 2

0.50° 4

0.75° 7

1.20° 12

1.90° 21

3.00° 33

4.25° 53

5.75° 103

8.00° 436

11.25° 6436

15.00° 15436

Performance comparison

POSY-II

MURRADAM,NG-1

SURF

SNS reflectometers will accumulate specular reflectivity data 10-50 times faster than the best existing instruments. ImprovedQmax will yield near-atomic-scale layer-thickness sensitivity.

Simulated data from 10-ÅSiO2 layer atop Si. SNS-Lutilizes 12 incident anglesi to measure Qmax > 0.9 Å-1

in t < 5 hours (18,000 s).Arrows indicate reflectivities measured in 12-24 hours(40-80,000 s) by existing instruments.

i ti (s)


59

SNS Powder Diffractometer


60

Detector Array


61

Characteristics of Major Components

• Source/Moderator - decoupled poisoned ambient water

t0 = 10 s at = 1 Å

• Incident Flight Path - 60 m moderator-sample distance

curved supermirror guide with 3cNi coating, 1.5 cm wide x 3 cm tall

~ 8 m moderator-guide distance adjustable 9 m guide-sample distance

• Chopper System - To and 2 bandwidth/frame-overlap choppers

• Collimators - variable aperture for incident beaminside scattering chamber - oscillating radial collimator

outside scattering chamber - fixed radial collimators

• Detectors - type TBD 10° – 170° in-plane, ±30° out-of-plane coverage (±45° at 90°) 40 mm tall x 5 mm wide pixel size~ 6 ster solid angle coverage, ~ 47 m2 area1 – 6 m variable distance from sample


62

Narrow Bandwidth Concept

• Previous TOF diffractometers used detector "banks" at a few angles, along with a broad wavelength range to produce a limited number of data sets of intensity vs. wavelength.

• A new idea put forward by Paolo Radaelli proposes the use of wide angular coverage and full 60 Hz operation to collect a single data set of intensity vs. angle and time-of-flight. These spectra would then be combined "appropriately" after-the-fact to produce a single histogram with intensity vs. d-spacing.

• This new data collection/analysis concept can be applied to any detector geometry. However, it appears optimally suited to a continuous detector locus, with this locus chosen to optimize the resolution as a function of d-spacing.


63

D-spacing-Lambda Space Coverage

0 1 2 3 4 5 6 7 80

5

10

15

20

25

low-resolution

high-resolution

fra

me

-3

fra

me

-4

fra

me

-5

fra

me

-1

fra

me

-22 = 20°

2 = 30°

2 = 60°

2 = 90°2 = 150°

narrow bandwidth discrete banks

d-s

pac

ing

(Å

)

incident lambda (Å)


64

GEM Powder Diffractometer at ISIS


65

Detector Locus

Lscat

= A + Bcot

8 m


66

D-spacing Coverage of POW-GEN3


67

D-spacing Coverage of POW-GEN3


68

Instrument Resolution Function

180 160 140 120 100 80 60 40 20 00.000

0.005

0.010

0.015

0.020

0.025

GEM-ISIS HRPD-ISIS POW-GEN3

Res

olut

ion

(fw

hm

d/d)

Scattering Angle (°)


69

Neutron Source

0 1 2 3 4 5 60

2

4

6

8

10

12

14

16

2MW-SNS POW-GEN3 0.15MW-ISIS GEM

x F

lux

at S

ampl

e (M

n.cm

-2.s

-1)

Wavelength (Å)


70

Neutron Source

0 1 2 3 4 5 6 7 8 9 100

10

20

30

40

50

60

70

80

2MW-SNS POW-GEN3 0.15MW-ISIS GEM

4 x F

lux

at S

ampl

e (M

n.cm

-2.s

-1)

Wavelength (Å)


71

Simulated Diffraction Experiment

1.00 1.05 1.10 1.15 1.20 1.25 1.30 1.35 1.400

2000

4000

6000

8000

10000

120000.5 gram Y-Al-Fe-O Garnet 60s (d/d = 0.0002)

POW-GEN3 GEM 90° Bank

coun

ts

d-spacing (Å)


72

Simulated Diffraction Experiment

0.45 0.50 0.550

200

400

600

800

10000.5 gram Y-Al-Fe-O Garnet 60s (d/d = 0.0002)

POW-GEN3 x10 GEM 155° Bank

coun

ts

d-spacing (Å)


73

Another Variation on Powder Diffraction: Residual Strain


74

SNS SANS


75

0 1 2 5 8 1 0 1 4d istan ce fro mm od era tor [m ]

Next Bea m lin

e

2.5m

Schematic Layout


76

Bender System: guide-bender-guide

tw

RRtw

RRR

La

LR

Ra

xR

LxRxLL

2 and ;

2);tan()

(cos(

;)sin(

)sin( ; with )1)(

2tan(

212

1

21

22

1

212


77

Bender System: Performance


78

Choppers

0

2

4

6

8

10

12

14

16

18

0 20 40 60 80

Time [ms]

Dis

tan

ce

fro

m s

ou

rce

[m

]

1.03Å

4.65Å

T1

T2

T3

0

2

4

6

8

10

12

14

16

18

0 20 40 60 80

Time [ms]

Dis

tan

ce

fro

m s

ou

rce

[m

]

3.72Å

7.3Å

T1

T2

T3


79

Soller Collimators: Configuration

14 m(S a m p le)

18 m(D etector )

10 m 12 m

G uid e


80

Soller Collimators: Direct Beam

2c m 1c m 4c m

16m 16m

14 m(S a m p le)

18 m(D etector )

10 m 12 m

G uid e


81

Soller Collimators: Resolution and Flux

8m pinhole1cm sample

1cm beam spot,2cm sample

1cm beamspot,

1cm sample

0 1 2 3 4F lux : 16m pinhole

0%

100%

200%

300%

0.1 1 10two-th ita [°]

Q/Q

Soller: source=1.75cm ,sam ple=1cm . Beam size ondetector =1cmSoller: source=3.5cm ,sam ple=2cm . Beam size ondetector =1cmpinhole: source-sam ple=8m ,detector-sam ple=8m

pinhole: source-sam ple=16m ,detector-sam ple=16m


82

Low Angle Detector

Needed:1 x 1 m2

5mm resolution 1Å103 n/s/pixel4 x 107 n/s/detector low background

Needed:1 x 1 m2

5mm resolution 1Å103 n/s/pixel4 x 107 n/s/detector low background

Available (3He):1 x 1 m2

7 mm resolution 5Å104 n/s/wire106 n/s/detectorLow background

Available (3He):1 x 1 m2

7 mm resolution 5Å104 n/s/wire106 n/s/detectorLow background

1.25 2.5 bar (concave structure)counting efficiencyresolutioncounting rate

5mm wire spacing.

1.25 2.5 bar (concave structure)counting efficiencyresolutioncounting rate

5mm wire spacing.D etek to r

B alas tkam m er ( H e)4

M em bran

K a lo tte(D ruckausgle ich)


83

High Angle Detectors

20 x Standard 3He PSD


84

Performance: Flux at the End of the Bender-Sytem


85

Performance: Flux at Sample (14m)

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

0 2 4 6 8 10 12 14

Wavelength [A]

Flu

xa

ts

amp

le[n

/s/c

m2

/A]

1 m co llim ation , S u m = 9.14 E 82 m co llim ation , S u m = 4.79 E 83 m co llim ation , S u m = 2.29 E 84 m co llim ation , S u m = 1.3E 8

`


86

Performance: Flux vs. Collimation

Max. counting rate: 700n/s/pixel at 1m collimation 100n/s/pixel at 4m collimation

1.E+06

1.E+07

1.E+08

1.E+09

0 5 10

Collimation length [m]

Inte

grat

ed F

lux

[n/c

m2/

s]

integrated flux between7.33 and 10.99ÅHFIR,9.16Å, 10%

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

0 5 10


Inte

grat

ed F

lux

[n/c

m2/

s]

integrated flux between3.66 and 7.33ÅHFIR,5.49Å, 10%

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

0 5 10


Inte

grat

ed F

lux

[n/c

m2/

s]

integrated flux between 1and 4.66ÅHFIR,2.83Å, 10%


87

Q-Coverage

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0 5 10Q [Å -1]

d

(Q)/

d

[cm

-1]

D 2O (coh + inc)

H 2O (coh on ly)

protein

lipid(solvent)

Qmin= 0.004 Å-1 (Pinhole) = 0.001 Å-1 (Soller)

Qmax = 12Å-1 (1st Frame)= 3.3Å-1 (2nd Frame)= 1.6Å-1 (3rd Frame)

3rd Frame 1st Frame

Huey HuangRice University


88

Performance (low angle detector)

Extend-Q SANS

30-Meter SANS, NIST (Q=0.0015-0.6 Å-1)

(=15%) Qmin [Å-1]

Simulated flux

×106 [n/s]

Qmin [Å-1] Measured flux(*)

×106 [n/s] 0.001-0.15(s) 0.8, 3 (2cm) 0.0015-0.3(s) 7, 25(2cm) 0.0015-0.013(10Å) 0.09 0.004-0.13 14 0.002-0.019(7.5) 0.26 0.006-0.25 120 0.003-0.025 0.85 0.008-0.35 170 0.0064-0.04 6.38 0.01-0.5 360 0.016-0.1 30.9 0.02-0.8 820


89

Performance

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

0.001 0.01 0.1 1 10

Q [1/Å]

Coun

tRat

epe

rSo

lidA

ngle

[arb

unit]

1st Fram e, 0-4m collim ations2nd F ram e, 0-4m collim ations3rd F ram e, 0-4m collim ationsSoller, 1-3 fram esSoller,2cm x2cm sam pleH igh Angle Detec tors, 1-3 fram esNIST 30m S ANSD11/ILL


90

100Å Polystyrene (0.625%) in 5mm D2O, 15sec simulation

1.E -02

1.E -01

1.E+00

1.E+01

1.E+02

1.E+03

0 0.05 0.1 0.15 0.2 0.25 0.3

Q [1/Å]

I(Q

)[n

pix

el-1

s-1

]Theore tica lExtended-Q SAN S, 2nd fram e, 4m sam ple-to-detector3 X H FIR SANS, 6Å,10% , 4m sam ple-to -detector

100ÅGuide Detector

4m 4m

Performance : MC simulation

Documents

SNS Experimental FacilitiesOak Ridge X0000910/arb Neutron Instruments for Materials Research T.E. Mason Experimental Facilities Division Spallation Neutron