Experimental Study of the Machian Mass Fluctuation Effect Using a µN Thrust Balance

1. Experimental Study of the Machian Mass Fluctuation Effect Using a µN Thrust Balance N. Buldrini, K. Marhold, B. Seifert and M. Tajmar Space Propulsion – ARC Seibersdorf Research nembo.buldrini@arcs.ac.at

2. 1 2 Machian Mass Fluctuations Impulse Term Exotic Mass Generator term Always negative!

3. Machian Mass Fluctuations Mass Fluctuation in a Capacitor Delivered Power ≈ Capacitor Volume

4. Mass Fluctuations for Propulsion Ballast Mass FluctuatingMass What if you can make the mass of a capacitor fluctuating and act on it in a direction when it is heavier and in the opposite direction when it is lighter?

5. Machian Mass Fluctuations The Devices Actuator(piezoelectric material) Capacitor Thrust Ballast Mass ~ Power Supply

6. The “Flux Capacitor” Machian Mass Fluctuations The Devices Coil ~ Capacitor ~ Electric Field Power Supply MagneticField Force

7. Machian Mass Fluctuations The Devices F E B

8. The Tested Devices E B Thrust Direction Capacitors are under the coil Mach-5CClaimed Thrust:~ 30μN Mach-6CClaimed Thrust:100-200μN

9. The Tested Devices

10. The Experimental Setup Vacuum Chamber and Thrust Balance Thrust Balance arrangement inside the Chamber. Balance succesfully tested with In-FEEP thrusters! Device Pivot Vacuum Chamber used for testingMaterial: Stainless SteelVacuum: 10-6 mbar Sensor Assmbly

11. The Experimental Setup Device Arrangement on the Balance

12. The Experimental Setup Thrust Balance Device Mounted on the Balance

13. The Experimental Setup Thrust Balance C-Flex G-10Flexural Pivots Thrust Balance Pivotand Device Feeding Cables

14. The Experimental Setup Thrust Balance Optic Sensor Detail Optic Sensor and Damping Actuator Assemblies

15. The Experimental Setup Thrust Balance Philtec D64 Fiber OpticDisplacement Sensor • Principle: Measures the reflection of light • Only fiber optic parts in the vacuum chamber (no EMI) • Noise: 0.008 µm (DC-100Hz)

16. The Experimental Setup Device Wiring Schematics Same setup used by Woodward and March. Amplifiers from March and original step-up transfomers from Woodward.

17. Experimental Results Mach-5C This kind of behaviour indicates the presence of thermal effects on the feeding wires

18. Experimental Results Mach-5C Predicted thrust at 90° phase shift between capacitor voltage and coil current: ~ 5µN Zero thrust predicted at 180° phase shift Thermal drift is still present.

19. Experimental Results Mach-6C - Capacitor Power - Coil Power- Thrust Trace Cap.voltage: 3.2 kVpCoil Field: 250 GaussFrequency: 52 kHzCap.V / Coil I - Phase Relationship: 90degExpect. Thrust: ~150µN The thermal drift has been reduced re-arranging the wiring and reducing the firing time to 2 seconds

20. Experimental Results Mach-6C 50µN Pulse Superimposed - Capacitor Power Cap.voltage: 2.5 kVpCoil Field: 200 GaussFrequency: 55 kHzCap.V / Coil I - Phase Relationship: 270degExpect. Thrust: ~50µN - Coil Power- Thrust Trace A pulse of 50µN was generated during the firing time by the calibration actuator, to test the response of the balance

21. Experimental Results Balance Response to Short Pulses A series of short pulses was generated using the calibration actuator, to evaluate the balance response at different thrust/pulse duration values

22. Experimental Results Mach-6C Mach-6C was sent back to Woodward to be tested again Then the device was sent back again to ARC-sr Tests in air by Woodward showed a thrust effect possibily due to an electromagnetic interaction.The device has been then potted, and tested in vacuum. A residual thrust of 100-200µN was recorded

23. Experimental Results Mach-6C Potted Cap.voltage: 3 kVpCoil Field: 200 GaussFrequency: 52 kHzCap.V / Coil I - Phase Relationship: 270degExpect. Thrust: ~75µN The phase relationship is changing during firing time, expecially at high capacitor power levels. Two calibration pulses of 50µN were generated with duration of 0.8 and 0.5 seconds to test the response of the balance in case of shorter thrust events

24. Experimental Results Mach-6C Potted Capacitor + CoilEnergized together Only CapacitorEnergized

25. Experimental Results Mach-6C Potted Only CapacitorEnergized (Shielded Cable) Only CapacitorEnergized

26. Experimental Results Test at Higher Frequency / Different Dielectric Dielectric: Titanium Oxide Series Tank Circuit Self-contained Device Voltage: 2.3 kVp Frequency: 2 MHz Expected Thurst: 1 ÷ 6 mNNo thrust was detected within the sensibility of the used electronic balance (0.1mN)

27. Conclusions and recommendations • Mach thrusters, tested by Woodward, were characterized using highly sensitive µN thrust balance used for electric propulsion • Our measurements rule out a thrust above 50% of the theoretical predictions and previous claims. It is likely, that this threshold is even reduced to 10% as indicated by part of our data. • A device operating at higher frequencies and with different dielectric was designed and built at ARC-sr. No thrust of the magnitude predicted by the models developed by Woodward/March/Palfreyman was observed • An upgrade of the sensor setup presently used by Woodward/March to a torsion balance or a ballistic pendulum setup is recommended • Due to the difficulties in keeping the right phase relationship between E and B fields, and thus same operating conditions, the development of a device based on a tank design is recommended • The development of a self-contained device similar to the one built at ARC-sr is proposed as well, using barium titanate as dielectric