Stroboscopic Detection

1
Stroboscopic Detection of Nuclear Resonant
Scattered Synchrotron Radiation R. Callens
I. Serdons
2
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Experiments
• Conclusion and Outlook

3
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Experiments
• Conclusion and Outlook

4
Aim
Extension of Nuclear Resonant Elastic
Scattering ofSynchrotron Radiation
Suitable for the investigation of long-lived
isotopes
5
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

6
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

57Fe
7
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

intensity
time
57Fe
8
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

9
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

10
Beating

• beating appears if two signals with a slightly
  different frequency are added
• beating frequency difference in frequency of
  both signals

11
Nuclear Resonant Scattering (NRS)
Scatterer Nucleus of one specific isotope(40K,
57Fe, 83Kr, 119Sn, 121Sb, 149Sm, 151Eu, 161Dy,
169Tm, 181Ta)

• Elastic scattering Local magnetic and electric
  information

Intensity(log-scale)
0
40
80
120
160
Time (ns)
12
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Experiments
• Conclusion and Outlook

13
Stroboscopic Data-Acquisition

• Restrict the data-acquisition to a
  periodic time window
• Frequency Analysis
• adapt the frequency of the time window
  (impossible in nuclear resonant scattering)
• adapt the frequency of the signal change
  the beating frequency

14
Stroboscopic Data-Acquisition
Beat frequency
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
15
Stroboscopic Data-Acquisition
Beat frequency
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
16
Stroboscopic Data-Acquisition
Beat frequency
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
17
Stroboscopic Data-Acquisition
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
18
Stroboscopic Data-Acquisition
Beat frequency
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
19
Stroboscopic Data-Acquisition
detection probability density
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
20
Stroboscopic Data-Acquisition
stroboscopic order n 2
s
700
t
n
u
600
o
c

f
500
o

r
detection probability density
e
400
b
m
300
u
n
200
100
0
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
21
Stroboscopic Data-Acquisition
stroboscopic order n 1
s
700
t
n
u
600
o
c

f
500
o

r
detection probability density
e
400
b
m
300
u
n
200
100
0
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
22
Stroboscopic Data-Acquisition
stroboscopic order n 0
s
700
t
n
u
600
o
c

f
500
o

r
detection probability density
e
400
b
m
300
u
n
200
100
0
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
23
Stroboscopic Data-Acquisition
stroboscopic order n -1
s
700
t
n
u
600
o
c

f
500
o

r
detection probability density
e
400
b
m
300
u
n
200
100
0
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
24
Stroboscopic Data-Acquisition
stroboscopic order n -2
s
700
t
n
u
600
o
c

f
500
o

r
detection probability density
e
400
b
m
300
u
n
200
100
0
T
2T
3T
4T
0
-10
-8
-6
-4
-2
0
2
4
6
8
10
time
velocity (mm/s)
25
Stroboscopic Data-Acquisition

• simulation for a-iron
• random oriented hyperfine field
• time-window frequency 2.21 109 Hz

Resonance frequencies can be determined from the
distance between the resonances within one
stroboscopic order
26
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Experiments
• Conclusion and Outlook

27
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
Fourier coefficients of time window function S(t)
R. Callens et al., Phys. Rev. B 67, 104423,
(2003)
28
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
Fourier coefficients of time window function S(t)
29
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
If the time window function S(t) is an even
function, sn is real
thin single-line sample
30
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
If the time window function S(t) is an even
function, sn is real
sample with hyperfine split energy levels
31
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
32
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
33
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
34
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
35
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
36
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
37
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
38
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
39
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
40
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
41
Simplified Mathematical Description
Stroboscopic resonances of order n ? 0 are
described by
42
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Experiments
• Conclusion and Outlook

43
Experimental Setup
BL09XU Nuclear Resonant Scattering Beamline
bunch period 23.6 ns
44
Experimental Setup
BL09XU Nuclear Resonant Scattering Beamline

• two kinds of data-acquisition systems
• conventional Mössbauer system
• two-dimensional data-acquisition system

bunch period 23.6 ns
45
Influence of the Time Window
2 single-line samples made of K4Fe(CN)6.3H2O
46
Influence of the Time Window
beat frequency
Reference
Sample
47
Influence of the Time Window
beat frequency
Reference
Sample
48
Influence of the Time Window
beat frequency
Reference
Sample
49
Influence of the Time Window
beat frequency
Reference
Sample
50
Influence of the Time Window
beat frequency
Reference
Sample
51
Influence of the Time Window
52
Influence of the Time Window

• The higher the time-window frequency, the larger
  the shift of the higher order spectrum
  components. ? The restrictions to the bunch
  mode are NOT correlated to the
  lifetime of the excited state in the isotope.

53
Influence of the Time Window
54
Influence of the Time Window
55
Influence of the Time Window
56
Influence of the Time Window
57
Influence of the Time Window
58
Influence of the Time Window

• The higher the time-window frequency, the larger
  the shift of the higher order spectrum
  components. ? The restrictions to the bunch
  mode are NOT correlated to the
  lifetime of the excited state in the isotope.
• By shifting the time window, the unknown
  amplitude is projected on another axis in
  the complex plane. ? The spectra contain
  phase information.

59
Magnetic Interaction
Alpha-iron
Reference sample (stainless steel) on Mössbauer
drive
60
Magnetic Interaction
Separation between lines within one stroboscopic
order 6.0 mm/s? B 32.3(8) T Shift with
respect to SS 0.04(9) mm/s
n 0
n -1
n 1
61
Other Applications

• Study of CaFeO3 under high pressure (S.
  Morimoto)
• The use of other isotopes than 57Fe (I. Serdons)

62
Overview

• Introduction
• Qualitative Approach
• Simplified Mathematical Description
• Investigation of the Time Window with the help
  of experimental data
• Conclusion and outlook

63
Conclusion and outlook

• Strobosopic detection is an effective tool for
• frequency analysis
• phase analysis
• The restrictions to the bunch mode are NOT
  correlated to the lifetime of the excited
  state in the isotope.
• For the study of 57Fe samples, high time-window
  frequencies are needed.
• Analysis of full data matrix is probably a
  better approach.
• Angle dependent phase information?

64
Collaborators
K.U.Leuven R. CallensR. CoussementS. GheysenC.
LabbéJ. Odeurs I. SerdonsK. Vyvey
Osaka University S. NasuT. OnoS. Morimoto
U.C.Louvain J. Ladrière
JASRI Y. YodaY. Yamada