Presentation for Phys 250 4222008 Magnetometry Outline Magnetometers General Setup Alkali Cell Optical Pumping Optical Probing Methods of Magnetometry DAVLL Combined Pumping and Probing ID: 336367
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Slide1
Hattie RingPresentation for Phys 2504/22/2008
MagnetometrySlide2
OutlineMagnetometers
General Setup
Alkali Cell
Optical Pumping
Optical Probing
Methods of
Magnetometry
DAVLL
Combined Pumping and Probing
RF vs. DC Magnetometers
SERF regime
Magnetometry
in MRI
Remote Detection
Future workSlide3
Magnetometer General Setup
Light Source
(pump)
Light Source
(probe)Slide4
Alkali Cell
Alkali
Atom
C
ellSlide5
Optical Pumping
Light Source
(pump)
Johannes
Recht
, W. K. (2005). Optical Pumping of Rubidium. MadisonSlide6
Optical Pumping
Light Source
(pump)
Rochester and
Budker
(2001). Am. J. Phys.
69
, 450-4.Slide7
Optical Pumping
Light Source
(pump)
Johannes
Recht
, W. K. (2005). Optical Pumping of Rubidium. MadisonSlide8
Optical Pumping
Light Source
(pump)
Magnetic Field
Johannes
Recht
, W. K. (2005). MadisonSlide9
Optical Pumping
Causes atomic polarization to
precess
Rochester and
Budker
(2001). Am. J. Phys.
69
, 450-4.
Light Source
(pump)
Magnetic FieldSlide10
Optical Pumping
Light Source
(pump)
Magnetic Field
Black, E. D. (2004). Optical Pumping. Slide11
Optical Pumping
Light Source
(pump)
Magnetic Field
Johannes
Recht
, W. K. (2005). MadisonSlide12
Probe Light
Two different detection modes:
Change in light intensity
Change in polarization
Light Source
(pump)
Light
Source
(probe)Slide13
DAVLL
Light Source
RCL
LCL
Laser Grating
Valeriy
V.
Yashchuk
, D. B., John R. Davis (1999).
Review of Scientific Instruments
71(2): 341 - 346.Slide14
DAVLL
Light Source
RCL
LCL
Laser Grating
Valeriy
V.
Yashchuk
, D. B., John R. Davis (1999).
Review of Scientific Instruments
71(2): 341 - 346.Slide15
Single Laser Setup
Light Source
(pump & probe)Slide16
Rf
Magnetometers
Light Source
(pump)
Light
Source
(probe)
Johnson noise can be neglected, allowing for better sensitivity.
Rf
Coil
M. P. Ledbetter, V. M. A., S. M. Rochester, D.
Budker
, S.
Pustelny
, V. V.
Yashchuk
(2008). Slide17
Spin-Exchange Relaxation Free (SERF)
Collision Avoidance:
Buffer gas
Cell coating
Two types of collisions in alkali cells:
Spin-exchange collisionsCan be ignored in SERFSpin-destruction collisions
Light Source
(pump)
Light
Source
(probe)
OvenSlide18
Nitrogen
Magnetometer
Pre-polarization
Field (~ 3 kG)
Encoding Field
(
B
0
, B
x
, B
y
, B
z
)
Water Out
H
2
O
Magnetometer with MRISlide19
Magnetometer with MRI
2 magnetometer setups
DC magnetometers
Modulated single laser setupSlide20
Remote Detection
Flow In
Flow
Out
Magnetometer
t
Detector
s(
t
)Slide21
Flow In
Flow
Out
Encoding Pulse
Magnetometer
Remote Detection
t
Detector
s(
t
)Slide22
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
Detector
s(
t
)Slide23
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
Detector
s(
t
)Slide24
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide25
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide26
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide27
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide28
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide29
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide30
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide31
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide32
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide33
Flow In
Flow
Out
Flow
Magnetometer
Remote Detection
t
t
flow
Detector
s(
t
)Slide34
Flow In
Flow
Out
Flow
t
t
flow
Signal (
nG
)
Time (s)
Detector
s(
t
)
Magnetometer
Remote DetectionSlide35
0.5 s
0.7 s
0.9 s
1.1 s
1.3 s
1.5 s
1.7 s
1.9 s
2.1 s
2.3 s
Signal (nG)
Time (s)
H
2
O
t
-sampling
Remote Detection ResultsSlide36
z
y
0.4 s
0.6 s
0.8 s
1.0 s
1.2 s
1.4 s
1.6 s
1.8 s
2.0 s
2.2 s
Resolution: z, 5mm; y, 2.5mm
Remote Detection ResultsSlide37
z
y
0.4 s
0.6 s
0.8 s
1.0 s
1.2 s
1.4 s
1.6 s
1.8 s
2.0 s
2.2 s
Resolution: z, 5mm; y, 2.5mm
Remote Detection ResultsSlide38
z
y
0.4 s
0.5 s
0.6 s
0.7 s
0.8 s
Flow Mixing Region
Remote Detection ResultsSlide39
Future Work
New System Being Built
Miniaturization
Optimized one-sided geometry
Prepolarization
for static imagingNQRMeasurementsNovel prepolarization techniques
Micro-channel flow, Lab-on-a-chip
RF MagnetometryEliminate point-by-point acquisitionDesign of system for direct imagingThe Brain
Hand-held scannersSlide40
References
Black, E. D. (2004). Optical Pumping
. http://www.hep.wisc.edu/~prepost/407/opticalpumping/opticalpumping.pdf
D.
Budker
, D. F. K., V. V. Yashchuk, and M. Zolotorev (2002). "Nonlinear magneto-optical rotation with frequency-modulated light." Physical Review A
65(055403): 1 - 4.Dmitry Budker, M. R. (2006). "Optical
Magnetometry.“M. P. Ledbetter, V. M. A., S. M. Rochester, D. Budker, S. Pustelny, V. V. Yashchuk
(2008). "Detection of radio frequency magnetic fields using nonlinear magneto-optical rotation.“I. M Savukov, S. J. S., M. V. Romalis, K. L. Sauer (2005). "Tunable Atomic Magnetometer for Detection of Radio-Frequency Magnetic Fields." Physical Review Letters 95(063004): 1 - 4.Johannes Recht, W. K. (2005). Optical Pumping of Rubidium. Madison
Shoujun Xu, S. M. R., Valeriy V. Yashchuk, Marcus . Donaldson, Dmitry Budker (2006). "Construction and applications of an atomic magnetic gradiometer based on nonlinear magneto-optical rotation."
Review of Scientific Instruments
77(8)
Shoujun
Xu
, V. V. Y., Marcus H. Donaldson, Simon M. Rochester, Dmitry
Budker
, and Alex Pines (2006). "Magnetic resonance imaging with an optical atomic magnetometer."
PNAS: 1-4.
Valeriy
V.
Yashchuk
, D. B., John R. Davis (1999). "Laser frequency stabilization using linear magneto-optics."
Review of Scientific Instruments
71(2): 341 - 346.