1. DEVELOPMENT OF HIGH RESOLUTION TRANSMISSION METHOD
Yoshiaki Kiyanagi*, Fujio Hiraga, Takashi Kamiyama, Akira Homma, Fumiyuki Fujita and Michihiro Furusaka
Division of Quantum Science and Engineering, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo , Japan *Contact person, Fax ,

2. Short summary of work performed in our university
Residual strain measurement and mapping of residual strain by Bragg edge transmission
Mapping of structure change around welded position (Under progress)

3. Principal of Bragg edge transmission
Sample
Transmitted
Neutron beam
Direct beam
Example of Transmission
SS304
2d detector
Moderator
Direct and transmitted beam is observed
Characteristic structure of Bragg edge will appear depending on the crystal structure and the texture.
Bragg edge

4. Energy Dependent Images
Polyethylene 5mm
Cd cover
Vinyl sheet 0.5mm

5. Energy dependent images from 0.001 to 70 eV

6. Material identification by using difference of cross sections
s from BNL325 A C B
Polyethylene Pb Fe A
この写真に示す、25mm角、0.5mm厚の鉄パイプの中に入った、5mmポリエチレン製のAの文字、最大で30mm厚の鉛ブロックをサンプルとし、取得した画像がこれです。この１、２、３の部分についてΣtを取ったものがこのグラフになります。このようにラジオグラフィー画像の任意の部位から各物質の特徴的な変化を得ることができました。 B C

7. Experimental setup for strain measurements
Site：Sirius beam line at KENS
Sample：5mm Fe
・As received
・180 degrees bending at two positions
Detector：Li-glass scintillator
Experimental setup
5.5m
28.5m
3.6m
37.6m
moderator
tail cutter
supermirror guide tube
sample
detector

8. Detector and sample 2d detector of Li-glass scintillators Bending load12 11 13 14 15 16 17 2 3 4 5 6 7 8 9 10 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 54 55 56 1 57 58 59 60 61 62 63 64 53
Expanded photo around load
Position of bending

9. hkl = (d1hkl – d0hkl) / d0hkl 100
Principal of strain measurements
Experimental data
Fitting result
Bragg edge is fitted by using a theoretical formula to define the Bragg edge position
Strain is defined as
hkl = (d1hkl – d0hkl) / d0hkl 100

10. Cross section at different row of the detector

11. Strain of each plane hkl / lane 1 2 3 4 5 6 7 8 431 0.07 0.01 -0.10
-0.05
0.04
0.05
-0.01
0.08
330
0.09
0.03
-0.04
321
-0.08
-0.02
0.02
-0.07
0.00
222
310
220
-0.03
-0.13
-0.11
211
-0.06
-0.09
200
0.12
0.11

12. Two dimensional distribution of the strain
Expanded photo of the sample y
Strain (%) x
Pixel number of the detector y 12 11 13 14 15 16 17 2 3 4 5 6 7 8 9 10 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 54 55 56 1 57 58 59 60 61 62 63 64 53 x y y
Strain (%) x x

13. Change of micro cross section around (110) planex y 12 11 13 14 15 16 17 2 3 4 5 6 7 8 9 10 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 54 55 56 1 57 58 59 60 61 62 63 64 53
Micro cross section (barns)
Neutron wavelength(A) x y
4.0Å y x
3.3Å
Micro cross section (barns) 1 2 3 4 5 6 7 8
(Row number) x

14. Summary for strain measurements
Strain was observed around the region where large load was expected.
Cross section varied around Bragg edges. The reason should be explained.

15. (Under progress at Hokkaido linac facility)
Inspection of the structure and texture around welded position by using neutron total cross section
6.8mm
5.1mm
Welded
Fe1
Fe2
1.4
1.2
1.0
0.8
Σ(cm -1 ) 4 3
wavelength(Å)
Welded
Fe1
HAZ1
Mixed1
1.4
1.2
1.0
0.8
Σ(cm -1 ) 4 3
wavelength(Å)
Welded
Fe2
HAZ2
Mixed2
3.4mm
Heat affected zone
(HAZ)
(Under progress at Hokkaido linac facility)

16. Micro structures appeared around Bragg edges of SS304

17. Change of effective total cross section of Si depending on the particle size
(Under progress)

18. Simulation of transmission of Be at different distance from sample to detector to study the effect of multiple scattering
There is almost no difference. There are no signals around direct beam. Is there problem in the kernel in forward direction?

19. Summary
(Effective) Total cross section is very strange, varying depending on the sample condition.
Experimental results are useful to consider or deduce the information included in the transmission cross section data.
It is necessary to perform the simulation calculation taking into account the crystal or texture structures in the sample.
It may not be easy to explain the total cross section data since it may include small angle scattering and so on.

20. Tentative Work Plan 1st Year
(1) Model experiments to get the effect of the crystal structure
(2) Texture observation of steel welding material by Bragg edge transmission
(3) Simulation calculations to study the effect of the beam divergence and multiple scattering on the imaging and the Bragg edge

21. (2) Designing of the code system for processing the imaging data
Work plan 2
2nd Year
(1) Data analysis and the explanation of the experimental data obtained last year
(2) Designing of the code system for processing the imaging data
3rd Year
Continuation of development of the data analysis
(2) Experiments on practical materials