hydrogen atomic clocks
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Hydrogen atomic clocks
J. Mauricio López R.División de Tiempo y Frecuencia
Outline
1. The Maser effect
2. Hydrogen Maser clocks
0. Introduction
3. Frequency stability of a Hydrogen maser clock
4. Metrology applications
5. Conclustions
INTRODUCTION
The Nobel Prize in Physics 1989
"for the invention of the separated oscillatory fields method and its use in the hydrogen maser and other atomic clocks"
"for the development of the ion trap technique"
Norman F. Ramsey Hans G. Dehmelt Wolfgang Paul 1/2 of the prize 1/4 of the prize 1/4 of the prize
USA USA Federal Republic of Germany
Harvard University Cambridge, MA, USA
University of Washington Seattle, WA, USA
University of Bonn Bonn, Federal Republic of Germany
b.1915 b.1922 b.1913d.1993
MASER
mplification by
mission of
adiation
timulated
icrowave
1958 invensión del láser
Charles H. Townes
Arthur L. Schawlow
Bell Labs
Bell Labs
“Infrared and optical Masers”, Phys. Rev. , 1958
The MASER effect
Spontaneous emission
Quantum system of two energy states
Ea
Eb
Spontaneous emission
Quantum system of two energy states
Ea
Eb ab EEhE
Spontaneous emission
Feymann diagram for the spontaneous emission effect
Eb
Ea
h1
Spac
e
Time
ba EhE 1
Stimulated emission
Quantum system of two energy states
Albert Einstein
Ea
Eb
Stimulated emission
Feymann diagram for the stimulated emission
Espa
cio
Tiempo
Eb
h1
Ea
h1
h1
11 2 hEhE ab
Efecto Láser
Short life time state
Long life time state
Ground stateE1
E2
E3
The three basic energy levels configuration for a laser effect
Optical pumping
Quick decay
Laser effect
Short life time state
Long life time state
Ground stateE1
E2
E3
The three basic energy levels configuration for a laser effect
Laser radiation
Laser effect
-Light amplification - Ground state
Excited state
photon
Basic elements of a Maser clock
= Resonance cavity + Gain medium
Interface +
Maser
Ener
gy
Ground state
Energy levels of He
Energy levels of Ne
E2
E1
E3
Collisions He-NeLong life time state
Pumping
(electric discharge) Quick decay
Laser light 632.8 nm
0 eV
20 eV
18 eV
Energy levels of a HeNe laser
F=2
F=1
F=1
F=0
F=1
F=0
F=1
F=01S
2S
2P
P 1/2
P 3/2
121.6 nm
10.969 GHz
1.0578 GHz
1.420 GHz
59.19 MHz
177.6 MHz
23.7 MHz
Electric interaction
Fine structure Hyperfine structure
Energy levels of a Hydrogen maser clock
Energy levels involve on the maser effect
Hydrogemn Masers realization
Magnetic shielding
Coild
Microwave cavity Glass bulb
antenna
Hydrogen atoms beam
Depósito de Hidrógeno
Selector de estados cuánticos
Basic architecture of a Hydrogen Maser clock
Vacuum chamber
27 cm
27 c
m TE011
F=1
F=0
0%0%
25%25%
0%
F=1
F=0
0%25%
25%
F=1
F=0
0%0%
0%25%
Quantum states selection
F=1
F=0
25%25%
25%25%
Mixer Amplifier
Phase detector
Syntheziser
250
5 MHz Frequency output
1.420 405 752 GHz
1.4GHz20.405 752 MHz
20.405 752 MHz
VCXO
5 MHz
Frequency synthesis chain for a Hydrogen Maser clock
Phase lock loop
Actual architecture of a Hydrogen maser clock (KVARZ)
Active Hydrogen Maser
Active Hydrogen Maser
Frequency stability of a Hydrogen maser clock
Log
(y(
))
Log (), seconds-3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
1 Day 1 Month
-9
-10
-11
-12
-13
-14
-15
-16Hydrogen maser
Rubidium
Quartz
Cesium
Frequency stability of atomic clocks
Hydrogen maser Metrology applications
1 2 3 n...
BIPM
n-1 “independent” measurements
n clocks
CENAM´s clock ensemble of the ETP-1
M2
2d Master Clock (Hydrogen Maser)
1
...
Master clock
2
x21
3
x31
n
xn1
x23=x21-x31
jjiiiiij xxxx ,12,11, ...
)(...)()( 1,1,11,21,11,11, jjiiii xxxxxx
)( 1,1
1
1,
1
1,
k
j
ikk
j
ikkk xxx
i j
Log
(y(
))
Log (), seconds0 | 2 3 4 5 6 7 8 9 7.0
1 Day1 Month
-9
-10
-11
-12
-13
-14
-15
-16
Time scale generation philosophy
Hydrogen Maser
Time scale algorithm
UTC
Time scale
.mauricio.lopez@cenam.mx
+ 52 (442) 211 0543
Hydrogen atomic clocks
J. Mauricio López R.División de Tiempo y Frecuencia
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