ear spin maser at highly stabilized low magnetic f and search for an atomic EDM A. Yoshimi RIKEN K. Asahi, T. Inoue, M. Uchida, N. Hatakeyama Dept. Phys., Tokyo Inst. Tech. The 18 th International Symposium on Spin Physics (SPIN08), UVa,2008/10/6-11.
26
Embed
Nuclear spin maser at highly stabilized low magnetic field and search for an atomic EDM
Nuclear spin maser at highly stabilized low magnetic field and search for an atomic EDM. A. Yoshimi RIKEN. K. Asahi, T. Inoue, M. Uchida, N. Hatakeyama Dept. Phys., Tokyo Inst. Tech. The 18 th International Symposium on Spin Physics (SPIN08), UVa,2008/10/6-11. - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Nuclear spin maser at highly stabilized low magnetic fieldand
search for an atomic EDM
A. YoshimiRIKEN
K. Asahi, T. Inoue, M. Uchida, N. HatakeyamaDept. Phys., Tokyo Inst. Tech.
The 18th International Symposium on Spin Physics (SPIN08), UVa,2008/10/6-11.
+++
+++
Time: t -t
Spin: s -s
EDM: d d
EDM and physics beyond the standard model
Non-zero EDM associated with spin Direct evidence of violation of time reversal symmetry
Time Reversal
In the standard model…. only possibility is CKM complex phase δCKM : → predicted EDM is too small to detect (105 smaller than the present experimental upper limit)
Beyond the standard model … detectable size of EDM is suggested : more than two CP violating phases
W W
f’fL fLe+iδ e -iδ
E
fL fR
E
Lie Rie
f~
f~
~
No EDM effect from one loop diagram
EDM effect from one loop diagram
EDM search with various species
Neutron EDM
EDM in diamagnetic atom
EDM in paramagnetic atom
Direct detection of neutronExperiment with UCN
Small EDM due to “Schiff shielding”Sensitive to T-violating interaction between nucleons.
Detection of electron EDM (small)Large enhancement in heavy element
Determination precision of the maser with different measurement time
Frequency precision
10-5
10-6
10-7
10-8
10-9
Fre
qu
en
cy p
recis
ion
(H
z)
10-4
102 103 104 105
Measurement time (s)
10
with previous setup
2/3
0.6 μHz@ 3x104 s
Determination precision of the maser with different measurement time
10-5
10-6
10-7
10-8
10-9
Fre
qu
en
cy p
recis
ion
(H
z)
102 103 104 105
Measurement time (s)
9 nHz@ 3x104 s
2/3
1
Frequency precision
10
10-4
with previous setup
with present setup
750 nHz@ 3x104 s
2 orders improvement
350 nA ; 1.4 μG ∼ 1.7 mHz
1.5 mHz
Drift of solenoid current
Frequency drift of the maser
2mHz driftNow investigating
Long term stability of the maser frequency
why δν -1/2 in t > 1000 s ? why δν get worse in t > 30000 s ?
Frequency fluctuation in 1000s-avaraging
10 nA ; 40 nG ∼ 50 μHz
100 μG → 100 nG → 125 μHz
1.) drift of solenoid current in 1000 s time scale
2.) drift of environmental magnetic field in 1000 s time scale
100 μHz
0 20000 40000 60000 80000(s)
0 20000 40000 60000 80000(s)
123.0
122.9
123.1
123.2
123.3
0 10000 20000 30000
(mHz)
(s)
Long term drift in solenoid B0 field
122
123
124
125
7.3537
7.3538
7.3539
7.3540
7.3541(m
A)
(mH
z)
Ongoing R&D for EDM experiments
High-sensitive Rb magnetometerTemperature control and current
Solenoid current
Temperature
∼2.5℃
Time (h)0 24 48 72 96 120
Long term drift of room temperature : δT 2.5 ℃ → drift of solenoid current : δI 500 nA
Temperature stabilization of current source → 0.1 ℃ in 1-day time scale → 5 nA fluctuation ( 20 nG )
Nonlinear Magneto-Optical effect of Rb atom
High sensitive magnetometer
D. Budker et al.,PRA 62 (2000) 043403.
k
Linear polarized light
Rb atom
Faraday rotation
B
1×104 rad/G, 4×10-12 G/Hz (B < 0.1G)
7.3530
7.3520
500 nA
20
22
24
( )℃
(mA)
10-13 G → 0.1 nHz → 10-29 ecm
Ongoing R&D for EDM experiments
Electric field application
Now testing the fabricate the field plate and cell in which the leakage current is Suppressed.
Digital feedback control
Temperature control
Test cell for electric field applicationAl – electric plate : 40 mmφGlass cell (Corning 7740, 7056) : 20 mm(h)
Calculation of feedback field by computer-based device.
Stabilization of cell temperature → Polarization, magnetic noise
68.7
68.8
0 5 10 15 20 25Time (h)
( )℃ 0.04 ℃
Summary and Future
● New scheme of spin maser -optical-coupling spin maser- has been constructed, and successfully operated at frequency as low as 33 Hz (under B0 = 28 mG)
● The spin maser has been operating with a stable static field (δB ~ 10nG).
● Frequency precision of the maser has reached 9 nHz, corresponding to an EDM sensitivity of 910-28 ecm (E=10kV/cm).
● Further improvements and developments are now being proceeded: Temperature control of current source and cell, Precise magnetometer, Electric field application, Precise maser feedback system.
● Measured fundamental characteristics indicate that this scheme would provide promising means to pursue a search for EDM in 129Xe atom down to a level of d(129Xe) = 10-29 ecm. ( 0.1 nHz).
Main frequency noise in EDM experiment
・ Sensitivity limit of the magnetometer : 10-13 G → 0.1 nHz → 10-29 ecm.
・ Magnetic noise of Rb atom in collision : 0.2 nHz → 10-29 ecm.
EDM in diamagnetic atom
SRd AA
EextEext + Eint = 0
0intext EEd
Eint
Schiff shielding
Total EDM effect with E is canceled I
SrdrZ
rdreSI
rdrr
3232 1
3
5
10
1
Electron angular momentum = 0
Sensitive to P,T- odd effect in nucleus
Atomic EDM is induced by the nuclear Schiff moment S
Schiff moment is induced by P,T-odd nuclear force
NRS
udF ddmf
mgG
~~32ππ
20πpp1
CP-odd pion exchange is dominated by chromo-EDM of quarks