Hydrogen atomic clocks

1. Hydrogen atomic clocks J. Mauricio López R. División de Tiempo y Frecuencia

2. Outline 0. Introduction 1. The Maser effect 2. Hydrogen Maser clocks 3. Frequency stability of a Hydrogen maser clock 4. Metrology applications 5. Conclustions

3. INTRODUCTION

4. 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

5. icrowave MASER mplification by timulated mission of adiation

6. 1958 invensión del láser “Infrared and optical Masers”, Phys. Rev. , 1958 Charles H. Townes Bell Labs Arthur L. Schawlow Bell Labs

7. The MASER effect

8. Eb Ea Spontaneous emission Quantum system of two energy states

9. Eb Ea Spontaneous emission Quantum system of two energy states

10. Ea Eb Space h1 Time Spontaneous emission Feymann diagram for the spontaneous emission effect

11. Eb Ea Albert Einstein Stimulated emission Quantum system of two energy states

12. Eb Ea Espacio h1 h1 h1 Tiempo Stimulated emission Feymann diagram for the stimulated emission

13. Laser effect Quick decay E3 E3 Short life time state Short life time state Long life time state Long life time state E2 E2 Optical pumping Laser radiation E1 E1 Ground state Ground state The three basic energy levels configuration for a laser effect Efecto Láser The three basic energy levels configuration for a laser effect

14. Ground state Excited state photon Laser effect -Light amplification -

15. = Resonance cavity + Gain medium + Interface Basic elements of a Maser clock Maser

16. Energy levels of a HeNe laser Collisions He-Ne Long life time state E3 E2 20 eV E1 18 eV Laser light 632.8 nm Pumping (electric discharge) Energy Quick decay Ground state 0 eV Energy levels of He Energy levels of Ne

17. Energy levels involve on the maser effect Energy levels of a Hydrogen maser clock F=2 P 3/2 23.7 MHz F=1 2P 10.969 GHz F=1 2S 177.6 MHz F=0 121.6 nm 1.0578 GHz F=1 P 1/2 59.19 MHz F=0 F=1 1S 1.420 GHz F=0 Electric interaction Fine structure Hyperfine structure

18. Hydrogemn Masers realization

19. Glass bulb Hydrogen atoms beam Microwave cavity antenna TE011 Selector de estados cuánticos Depósito de Hidrógeno Coild Magnetic shielding 27 cm 27 cm Vacuum chamber Basic architecture of a Hydrogen Maser clock

20. 0% 25% F=1 0% F=0 0% 0% 25% F=1 25% F=0 0% 25% 25% 25% F=1 25% F=1 25% F=0 25% 0% F=0 0% Quantum states selection

21. Amplifier 1.420 405 752 GHz 1.4GHz  250 Syntheziser Phase detector 5 MHz VCXO Frequency synthesis chain for a Hydrogen Maser clock Mixer 20.405 752 MHz 20.405 752 MHz Phase lock loop 5 MHz Frequency output

22. Actual architecture of a Hydrogen maser clock (KVARZ)

23. Active Hydrogen Maser

24. Active Hydrogen Maser

25. Frequency stability of a Hydrogen maser clock

26. Frequency stability of atomic clocks -9 Quartz -10 -11 Rubidium Log (y()) -12 -13 Cesium -14 -15 Hydrogen maser -16 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Log (), seconds 1 Day 1 Month

27. Hydrogen maser Metrology applications

28. 1 2 3 n n clocks M2 BIPM 2d Master Clock (Hydrogen Maser) n-1 “independent” measurements ... CENAM´s clock ensemble of the ETP-1

29. i j 1 2 3 n x23=x21-x31 ... x21 x31 xn1 Master clock

30. Time scale generation philosophy Hydrogen Maser Time scale algorithm UTC Time scale -9 -10 -11 Log (y()) -12 -13 -14 -15 -16 0 | 2 3 4 5 6 7 8 9 7.0 Log (), seconds 1 Day 1 Month

31. Hydrogen atomic clocks J. Mauricio López R. División de Tiempo y Frecuencia . mauricio.lopez@cenam.mx + 52 (442) 211 0543