John Hartnett, Mike Tobar, Rhys Povey, Joerg Jaeckel The 5th Patras Workshop on Axions, WIMPs and WISPs DURHAM UNIVERSITY

Michael E. Tobar ARC Australian Laureate Fellow School of Physics University of Western Australia, Perth Frequency Standards and Metrology Research Group Frequency Standards and Metrology Precision Microwave Oscillators and Interferometers: From Testing Fundamental Physics to Commercial and Space Applications

High-Precision Oscillators, Clocks and Interferometers Generating and measuring frequency, time and phase at the highest precision Space

Research Testing fundamental physics 1. Lorentz Invariance 2. Rotating cryogenic oscillator experiment 3. Odd parity magnetic MZ Interferometer experiment 4. Generation and detection of the Paraphoton Commercial Applications 1. Microwave Interferometer as a noise detector 2. Sapphire Oscillators (room temperature and cryogenic) Atomic Clock Ensemble in Space (ACES) Mission 1. Australian User Group 2. Long term operation of high precision clocks Astronomy 1. Cryogenic Sapphire Oscillators better than H-masers 2. With MIT, image black hole at the centre of the Galaxy 3. Within Australia -> SKA and VLBI timing

 Whispering Gallery modes WGE(H) mnp  Vertically stacked  TM 0np (n = 0,1; p = 0,1,2,3)  Vertically stacked  TE 0np (n = 0,1; p = 0,1,2,3)  Vertically stacked

WGE 16,0,0

HEMEX Whispering Gallery Mode Sapphire resonator WGH 16,0,0 at GHz

Cavity mounted inside inner can

copper nut sapphire copper clamp silver plated copper cavity primary coupling probe secondary coupling probe 10 8

TE mode: E θ field

TM 010 TE 011

Paraphoton wavenumber Cavity resonance frequency

Resonance Q-factor coupling Paraphoton mass |G|~ 1

Assuming P em = 1 W, P det = W, Q ~ 10 9, χ ~ 3.2 × Probability of Detection

For 6 pairs of Niobium cylinders (stacked axially) with 2 GHz < ω 0 /2π < 20 GHz and ω 0  k  0 Microwave cavities Q~10 11, ….6 orders of magnitude better than Coulomb experiment

k γ = paraphotonk 0 =ω 0 /c (resonance)k γ 2 =ω 2 – m γ 2

 Q =Rs/G G=Geometric factor & Rs = surface resistance G [Ohms] Freq [Hz] 10 GHz mode T ≤ 4 K Niobium Q~ 10 9

 In sapphire very high Q ~ 10 9 without Niobium  ? G for high m seems small, need to confirm, as numeric integral needs to be checked

 Assuming  detection bandwidth  f = 1 Hz  receiver temperature T = 1 K (very good amp) thermal noise power kT  f = -199 dBm per second S/N = 1 freqhf/sdBmSeconds 10 GHz6.63E GHz6.63E

 Isolation will be the biggest problem  Microwave leakage  Unity coupling probes to cavities  No reflected power  Tuning High Q resonances exactly to the same frequency