amk_jeep_sac9

concretecakeΠολεοδομικά Έργα

29 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

44 εμφανίσεις

Beamline A



Joint Engineering, Environment and
Processing Beamline


(
JEEP
)

Alexander Korsunsky

Department of Engineering Science

University of Oxford

Parks Road, Oxford OX1 3PJ

Acknowledgments
:

P.J. Withers, A. Pawley, M. Henderson, P. Barnes, P.J. Webster, D.
Laundy, S. Collins, G. Davis, J. Elliott, R. Lewis, M. Daymond and
other members of the working group

Another

high energy

beamline

for DIAMOND?

High energy beamline

for general engineering use (
JEEP
)

What is a modern engineer?

Engineers deal with objects, either designed &
manufactured, or naturally occurring, that are intended
to perform a certain function in an optimal way.

This function is often load bearing.

An engineer in this context could be a mechanical or
materials specialist, concerned with chemical or
deformation processing, or with natural structures such
as minerals or our bodies (bio
-
medical).

Engineers share common goals, requirements and
methods.


Non
-
destructive / non
-
invasive


Fast and efficient


High contrast and low noise


Spatially resolving down to sub
-
micron
level


Specific to chemical species


Phase specific


Orientation specific

Modern engineer’s ideal tool ?


Highly penetrating


Suitably parallel


High flux


Interacting with matter on a variety of
scales


Moderately absorbed


Efficiently detectable

Modern engineer’s ideal tool


a
high energy synchrotron X
-
ray beam!

is a
beam

Penetration depth (mm)

0.0001
0.001
0.01
0.1
1
10
100
1
10
100
1000
Energy (keV)
penetration depth (mm)
Aluminium
Iron
Niobium
JEEP
: “Synchrotron
-
assisted engineering“


M
ission: “image and measure in situ real engineering structures”


JEEP

will be the first instrument to be truly designed for engineers


will be a world beater


JEEP

will offer unprecedented flexibility and range thanks to the
two
-
hutch design philosophy


JEEP
‘s sample
-
centred design will allow installation and use of
large scale manipulation and environmental control equipment


that will match the scale of a synchrotron facility for the first time


JEEP

will be a truly general purpose


operation mode and
beamline optics will be tuned to the sample (physical size,
microstructure, grain size, etc.)

Rise of Synchrotron

Engineering Research

Will synchrotron scanning for engineering

continue to double every 3 years?

Percentage of publications on the
strain scanning use of synchrotrons

Tension

Compression

Compression

Tension

By scanning the
object very
precisely through
the gauge volume
it is possible to
build up 3D maps
of the lattice
parameter (and
hence phase and
strain) throughout
the object.

x

y

Gauge Volume

3D internal mapping

Tomographic

Energy
-
Dispersive

Diffraction

Imaging

scan

of

6
×
13

mm

area

inside

a

a

bulk

(
80

mm
.

thick)

concrete

block

showing

regions

of

aggregate

(calcite,

dolomite)

and

binding

cement

hydrate

(portlandite,

ettringite)
.


TEDDI

(Paul Barnes et al. Birkbeck College & SRS)

Multi
-
phase reactions under high P

(A. Pawley, M.Henderson et al., SRS)

The atomic strain gauge
-

Change in spacing between the
rows of atoms is recorded as a shift in the diffraction peaks


Strain scanning

Residual stresses in gears

Residual stresses are often
controlled by processing in order
to provide improved durability.

Reliable quantification of these
effects requires accurate stress
mapping.

The example shown is the residual
stress map in a slice form a gear
tooth of a large marine gear

(Korsunsky et al., Oxford & SRS, 2002)

Residual stresses in welds and

weld process optimisation

Welding Torch

Filler Wire

2024 Plate

Mechanical
Constraint

Direct FE Validation

Longitudinal strain in a TIG weld

Model

Synchrotron

Model

Synchrotron

Transverse strain in a TIG weld

(P.J.Webster et al, Salford & ESRF)

Understanding fatigue resistance of
structural materials is key to improved
durability. Crack tip strain fields can be
mapped directly in detail …

… and compared with the theoretical
predictions of fracture mechanics.

Linear elastic fracture mechanics

(Korsunsky et al., Oxford & ESRF, 2001)

3D image: crack plane in Ti/SiC
f
composite

(P.J.Withers et al., ESRF, 2001)

Diffraction
-
enhanced imaging

(R.Lewis et al., Elettra & SRS)



Peak of Analyser

Refraction

Image contrast

(R.Lewis et al., Elettra & SRS)

Endobon graft

(G.R. Davis, J.C. Elliott et al, QM&W)

Of beamline design


Strain scanning was not envisaged on SRS or ESRF
before the instruments were built


However, flexibility of the original instrument design
(space, beam height, detectors, etc) meant that we could
easily exploit the excellent beam characteristics


When designing instruments, make sure short term
thinking does not constrain possible future users

Referees’ views


“JEEP will occupy a unique niche between lower energy
XRD and neutron diffraction and will bridge the length
scales accessible by those techniques



“It is important to recognise that
large sample sizes and
associated equipment are key to bridging micro
-

and
macro
-
scales



“JEEP will
contribute to improved engineering
(decreased time
-
to
-
application) and improved predictive
ability in various areas of science”

Referees’ views


“With ENGIN and JEEP the climate seems right for
significant innovation and breakthroughs. At this time,
the infrastructure and political will to emphasize
engineering are present




The engineering studies will complement the time
resolved work nicely and will result in tools that will
shorten the development cycle”


“It is an area of obvious academic and economic impact”


“The two
-
hutch design will work and will allow for set
-
up of complex engineering experiments without
interrupting the experimentalists in the first hutch


Referees’ views


JEEP to ENGIN is like DIAMOND to ISIS


“A compelling reason for locating Diamond at RAL in the
first place was the synergy between ISIS and the new
synchrotron facility”


“The engineering instrument on DIAMOND will certainly
hold a considerable resolution advantage over ISIS.
However, a 5 year head start on the ENGIN
-
X project (to
operate in 2003) will provide considerable infrastructure,
industrial contacts and personnel expertise on which JEEP
beamline can draw



“The exterior hutch on JEEP (Engnineering Applications
Centre) will help coordinate work between ISIS and
DIAMOND”


Challenges


A broad mission, built not on a single technique,
but on the affinity of discipline(s)


Clear need for strong management procedures to
reconcile the different aspects of science to be
tackled


Great need for excellent staff to provide technical
scientific and computing support


Need for excellent procedures for continuous
development and adoption of best optics, detectors
and ancillary equipment solutions

Beamline layout




The
JEEP

concept




The
JEEP

concept




EAC

The
JEEP

concept

Source specification:
Undulator vs MPW

1.0E+12
1.0E+13
1.0E+14
1.0E+15
1.0E+16
10
100
1000
10000
100000
Photon Energy (eV)
Flux
1.6 T MPW
BM
10T WS
U48
U80
U36
3.5 T MPW
Source specification:
Undulator vs MPW

1.0E+14
1.0E+15
1.0E+16
1.0E+17
1.0E+18
1.0E+19
1.0E+20
1.0E+21
10
100
1000
10000
100000
Photon Energy (eV)
Brightness
U36
U24
U48
U80
1.6T MPW
BM
10T WS
U200
3.5T MPW
U20 IV
Hard to focus?


3rd generation undulators work at well 80keV+


Divergence: undulator 100

20µrad, wiggler 1

0.2mrad.


Bragg angle at 100keV(Si 111): ~1º


need higher orders?


Darwin width at 100keV (Si 111): ~0.5 arc seconds
(decreases with energy)


Mirror critical angle 0.7mrad at 100keV


Sagittal monochromator: R~0.4m at 100keV


Heat loading highest for high field MPWs

Focusing Solutions


Mirrors


collect too small a fan at high energy. Kirkpatrick
-
Baez?


Multilayers


beam is deflected


bandpass ~ 10
-
3
. Slope errors?


d~100
Å:

small Bragg angle, need long multilayers


Possible use for vertical focussing where radiation fan is smaller


Bragg


Long crystals + in double bounce beam moves a long way


sagittal bend
-

up to 60keV with high order reflection


meridional bend deflects beam so fixed wavelength only


Laue

Power of Diamond IDs


Diamond Undulators


Power up to 6 kW


Power density up to 19 kW/mrad/mrad



Diamond MPWs


Power up to 50kW


Power Density 23kW/mrad/mrad



Cornell G Line
-

17kW in 1.7mrad


Laue focusing


Near normal incidence means lower heat loading


Integrated reflectivity depends on thickness
-

more intensity?


Asymmetrically cut crystals (Zhong, Kao, Siddons et al. 2001).


Anti
-
clastic curvature: lower divergence contrib. to bandpass +
vertical focusing


Two crystal arrangement allows fixed offset for tunability

focus
source
S
F
Laue-Bragg
S
F
Laue-Laue
Sagittal:
1mrad

to 0.4mm (NSLS)

Meridional:

E/E~4

10
-
4
;1mrad to 0.5mm

Optics and detectors


At present, there is no “off the shelf“ solution


Feasibility study required into sagittal focusing
monochromators for SRS (16.3, 16.4, 9.1 etc.)


Further work required on making a bender,
understanding dynamical diffraction in distorted crystals,
graded crystals.


Possible use of refractive optics?


Detector systems evolve rapidly (eg CCDs)


initial
choice will be made in about 24 months


Dual hutch philosophy: choice of resolution vs area
available for both beam and detectors


Management


The
JEEP
project will be managed in the design,
construction and operation stages by a panel of experts
each championing an engineering application theme


The panel will include two representatives from
industry and one liaison member from ISIS


Chair of the panel will rotate annually between theme
representatives


The panel will be tasked with maintaining the balance
between themes


The panel will advise on optimal experiment
scheduling

Development framework


The choice of initial range of detector systems will be
based on further research during the next two years


Large scale ancillary equipment will be separately
funded and developed within ‘clusters’ of experts which
will deliver it for the use by all other users


The outer hutch will provide a special location and
unprecedented opportunities for development


Special capabilities will be developed for off
-
line
experiment set
-
up based on laser coordinate
measurement procedures


Availability of the outer hutch will encourage
involvement of UK industry in longer term projects

Equipment

Optics hutch 1 (inner)





Slits/shutters

Monochromator/Focussing


Experiment hutch 1 (inner)


Kappa diffractometer (e.g. KUMA)

Translation/Mini
-
loadrig/Thermal

Theodolites / Laser positioning

Detector arrays

Optics hutch 2 (outer)


Slit/shutters

Monochromator/Focussing


Experiment hutch 2 (outer)


Building (double storey height, crane)

Translation


Cost estimate: £3.5M

Conclusions


JEEP

will be a world beater


thanks to clear vision of the
objectives and targeted design


JEEP

will offer unprecedented flexibility and range
thanks to the two
-
hutch design philosophy


JEEP

will be a truly general purpose


operation mode
and beamline optics will be tuned to the sample (physical
size, microstructure, grain size, etc.)


JEEP

will have built
-
in management and development
procedures to ensure rapid adoption of best techniques