Demonstrating Electromagnetic Properties of a MADMAX prototype - PowerPoint PPT Presentation

Demonstrating Electromagnetic Properties of a MADMAX prototype booster Jacob Egge for the MADMAX collaboration 1

Axions MADMAX: MA gnetised D isk-and- M irror A xion e X periment ● Solution to the strong CP problem ● Dark matter candidate Credit: A. Ringwald Mar 22 2018 2 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Basic Principle 2 − 2 ( B e 2 ⋅ f (ϵ 1, ϵ 2 ) − 27 W m tiny power P / A = 2.2 × 10 10 T ) C a γ → boost needed Mar 22 2018 3 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Basic Principle Solution: Use many discs ● Resonance and constructive interference of emissions Boost factor (β 2 ) simulation 2 Power of booster − 2 ( B e 2 ⋅ f (ϵ 1, ϵ 2 )⋅β − 27 W m 2 Power of singlemirror P / A = 2.2 × 10 10 T ) C a γ Mar 22 2018 4 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

20 Disc Setup Mirror Sapphire Discs Mar 22 2018 5 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

20 Disc Setup Vector Network Parabolic ● 20 disc seed setup Copper Analyzer Mirror Antenna Mirror ● No magnetic field ● Test electromagnetic response with a Vector Network Analyzer Mar 22 2018 6 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

One Disc System System characterization via Group Delay: Phase τ g =− d ϕ Angular Frequency d ω Mar 22 2018 7 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Mechanical Precision Temperature Response Motor Hysteresis ● Thermal expansion changes disc ● Command motor to the same position distance coming from different directions Mar 22 2018 8 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Reflections Mirror only Mirror Peak ● Additional unwanted reflections in the system ● antenna mismatch, surroundings, ... ● Removal by time gate ● But: In a many discs Secondary Reflections system signal and 1 2 3 unwanted reflections overlap Mar 22 2018 9 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Reflections τ= 7 ns τ= 8.7 ns One disc system τ= 10 ns τ= 12 ns → Necessary to model additional reflections Mar 22 2018 10 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Reflections Idea: Include reflections in simulation Measurement Mirror only Mar 22 2018 11 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Reflections Idea: Include reflections in simulation Measurement Simulation Mirror only Mar 22 2018 12 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Reflections Mirror only preliminary ● Simulation reproduces group delay reasonably well ● Uncertain behavior for many discs Mar 22 2018 13 MADMAX: MA gnetised D isk-and- M irror A xion e X periment

Conclusion and Outlook ● Effect of disc tilts → Automatic tilting ● Mechanical precision of μm ● Losses 12 ns ● Absolute positioning → Interferometer ● Reflections cause problems Mar 22 2018 14 MADMAX: MA gnetised D isk-and- M irror A xion e X periment