3.1 Photon radiation pressure

A photon of frequency ν carries energy E = hν and momentum p = E/c. Reflecting off a perfect mirror, it transfers momentum 2p to that surface.

Example: P = 100 W, R = 0.999 → F ≈ 6.67 × 10⁻⁷ N (0.667 µN)

3.2 Resonant-cavity amplification — corrected

A high quality factor Q means a cavity stores much more electromagnetic energy per watt of continuous dissipation — that part is standard microwave engineering. It does not follow that net photon thrust scales linearly with Q. Treating F = Q·(1+R)·P/c as a thrust law double-counts the same photons on every round trip instead of tracking net momentum delivered to the outside world.

Any genuine net thrust would have to come from an asymmetry between the momentum flux striking the two end walls of the cavity — the same claim made about earlier asymmetric-cavity thruster proposals, and that subsequent testing (White et al. 2016 in vacuum; Kraft et al. 2021 at TU Dresden) failed to confirm once thermal and mechanical artifacts were controlled for. NOAH-QPS treats this as an open experimental question, to be settled by the differential ΔF measurement described in the V1 Prototype tab — not assumed.

3.3 Static Casimir effect — internal force, not net thrust

Between two parallel conducting plates separated by distance d, quantum vacuum fluctuations generate a real, measurable attractive force. This has been confirmed experimentally (Lamoreaux 1997) and is not in question.

Example: d = 1 µm, A = 1 mm² → F ≈ 1.3 × 10⁻¹² N (1.3 pN)

Correction: if both plates are internal parts of the same closed system, this is an internal force pair — by momentum conservation it cannot, by itself, accelerate the system's center of mass. It could only contribute to net thrust if coupled to something that carries momentum away from the system (e.g. emitted photons), which has not been demonstrated here.

3.4 Dynamic Casimir effect — an experimental hypothesis, not a thrust source

If one plate oscillates at high (GHz) frequency, the quantum vacuum generates real photon pairs — this phenomenon itself is experimentally confirmed (Wilson et al., Chalmers, 2011).

Correction: that confirmation is for photon-pair production in a superconducting circuit, not for propulsion. Using the dynamic Casimir effect as a thrust mechanism in NOAH-QPS is a hypothesis to be tested, not a validated contribution to be added into a performance budget.

3.5 Quantum materials

[G] External housing & structure

Aluminum 6061-T6 or CFRP composite shell, copper-mesh Faraday cage EMI shielding, glycol-water cooling loop and radiators, vacuum-tight SMA/BNC/D-sub feedthroughs. Propulsion module: ~50–100 kg, 500×500×400 mm (excluding cryostat).

5.1–5.2 Resonance & quality factor

These are the two numbers the whole design pivots on, and neither is fixed yet — they fall out of whatever cavity dimensions the EM simulation converges on.

Illustrative only: a = 55 mm, L = 150 mm → f ≈ 2.45 GHz. This a, L pair is a starting point for the simulation sweep, not a frozen dimension.

Illustrative only: OFHC copper, σ = 5.96 × 10⁷ S/m, V/S ≈ 0.020 m → Q ≈ 10,760. This suggests the >10,000 target is reachable for this class of geometry — it is not a guaranteed result, and must be confirmed by S₁₁ / ring-down measurement on the built cavity.

5.5 Thermal budget

Continuous dissipated power in the cavity reaches ~1000 W once the Q-factor amplification is included — far beyond what a milliwatt-class dilution cryostat can absorb continuously.

Solution — pulsed operation: 1 ms pulses every 10 s (duty cycle < 0.01%) brings average dissipation down to ~1 W, within the cryostat's budget.

6 Bill of materials

Component	Material	Specification
Resonant cavity	OFHC copper (C10100)	σ > 5.96×10⁷ S/m, purity >99.99%
Internal coating	Silver (Ag)	5–10 µm, σ = 6.30×10⁷ S/m
Surface protection	Gold (Au)	0.1 µm, anti-oxidation
MEMS membrane	SiN	1 µm thick, E = 250 GPa
Actuator	PZT ceramic	d₃₃ ≈ 300 pm/V, ±100 V
Superconducting option	Nb-Ti / YBCO	T꜀ = 9.2 K / 92 K
Structure	Al 6061-T6	σᵧ = 276 MPa, 2.70 g/cm³

6.2 Fabrication sequence

• Machining — 5-axis CNC, ±10 µm tolerance, electrolytic polish to Ra < 0.4 µm
• Coating — electroless/electrolytic silver then gold plating, SEM-verified
• MEMS fabrication — photolithography, LPCVD SiN, RIE etch, KOH sacrificial release
• Assembly — Cu-Cu laser welding or brazing, plasma + ultrasonic cleaning
• Testing — vacuum, RF (VNA), thermal cycling 300 K → 10 mK → 300 K, force calibration

7 Control loops

Loop	Sensor	Actuator	Performance
Temperature	Cernox thermometer	Heaters + cryostat	±0.1 mK at 10 mK
Vacuum pressure	Ion gauge	Piezo valves + pumps	±10%, <5 s response
Frequency lock	Phase detector	Magnetron control voltage (PLL)	<1 Hz on 2.45 GHz
MEMS mirror position	Capacitive electrodes	PZT ±100 V	<1 nm resolution

Parameter	Status	Note
Net photonic thrust	Unconfirmed	Depends on wall-asymmetry momentum transfer — not on Q; to be measured as ΔF
Static Casimir contribution	Internal force	~1.3 pN between internal plates (1 µm gap, 1 mm²) — real, but not net external thrust by itself
Dynamic Casimir contribution	Hypothesis	Photon-pair production is confirmed physics; its use as thrust is untested here
Specific impulse (Isp)	Not computable yet	Requires a confirmed net thrust value, which does not currently exist
Electrical consumption	Specified	100 W RF input (design parameter, independent of the thrust question)
Mass (propulsion module / cryostat / total)	Estimated	50–100 kg / ~500 kg / ~600 kg
ΔF = F_meas − F_conventional	To be measured	The one number the V1 rig exists to produce, with its full uncertainty budget

Why there's no energy-balance or Δv figure here

Efficiency, acceleration and Δv were previously computed from the retracted thrust figure and are removed for the same reason — they would just propagate the same error one step further. Those numbers can be recomputed honestly the moment V1 produces a measured, artifact-checked ΔF.

9 How it compares — with the open question flagged

Parameter	NOAH-QPS	Asymmetric RF-cavity concept (historical)	Ion (Xe)	Chemical
Thrust	Unconfirmed (pending ΔF)	0 (debunked)	0.1–5 N	10³–10⁶ N
Isp	Not computable yet	N/A	2000–5000 s	300–450 s
Power	100 W	N/A	1–10 kW	N/A
Efficiency	Not computable yet	N/A	50–80%	30–50%
Status	V1 experimental prototype	Refuted (thermal/mechanical artifacts)	Operational	Operational

1 · Thermal losses in the cavity

~1000 W of dissipation in pulsed operation must be removed without disturbing vacuum or temperature. Approach: very-low duty-cycle pulsing, thermal conduction to the cryostat, high-conductivity materials (diamond, graphene), superconducting low-loss coatings.

2 · Vacuum stability

Ultra-high vacuum (<10⁻⁹ mbar) must be held for years in orbit. Approach: integrated ion pump, Ti/Zr getters, low-outgassing 316L steel and OFHC copper, elastomer-free ConFlat seals.

3 · MEMS mirror alignment

The mirror must track nanometre-scale precision relative to the cavity. Approach: active PID control, capacitive sensing, electrostatic + PZT actuation, thermal-expansion compensation.

4 · Helium-3 consumption

He3 is scarce and costly (~$1000/L). Approach: recovery/recycling loops, adsorption cryocoolers as a He3-free alternative, or long-term migration to high-T꜀ superconductors (YBCO, 92 K) that skip dilution refrigeration entirely.

11 Test protocol

Stage	Test	Goal
Ground	RF characterization	Measure Q, verify resonant modes (VNA)
Ground	Vacuum test	Leak check, verify final pressure
Ground	Cryogenic test	Cool to 10 mK, verify thermal stability
Ground	Force test	Optical torsion balance, 1 pN sensitivity
Vacuum chamber	Simulated microgravity	Drop tower, ~10 s free fall
Flight	Suborbital flight	Sounding rocket, ~5 min microgravity
Flight	Orbital mission	CubeSat (3U/6U), months-long orbit-correction test

Core uncertainty metric

The central quantity of the whole program is the differential force, budgeted against thermal, mechanical, RF, calibration, model, and environmental error sources:

A candidate signal only counts as real if it is reproducible, correlated with the RF excitation, survives artifact controls, and remains after every conventional transfer mechanism has been closed out.

General architecture — two coupled chains

It's this separation — a drive chain and an independent, fully-synchronized measurement chain — that turns NOAH-QPS from "just an RF cavity" into a genuine experimental platform.

1 · Mechanical subsystem

ID	Component	Function
MC-001	Cavity main body	Primary mechanical & electromagnetic enclosure. OFHC copper recommended; parametric cylindrical geometry — diameter, length, wall thickness and finish are not frozen yet, they follow from the target mode and frequency.
MC-002	Front flange	Cavity closure, mechanical interface, optional coupler feedthrough, instrumentation access
MC-003	Rear flange	Closure, stiffening, instrumentation interface, mechanical symmetry
MC-004	External structure / support	Holds the cavity, transmits force to the measurement system, suppresses parasitic motion (Al, stainless, or low-expansion alloy per thermal analysis)

2 · RF subsystem

ID	Component	Function
RF-001	RF source	Generates the excitation — frequency, power, frequency/phase stability, phase noise, 50 Ω impedance. A controllable commercial source is preferred over a custom generator for V1.
RF-002	RF amplifier	Raises source power to P_RF; enables power sweeps (0, 1, 5, 10, 20, 50, 100 W). Real maximum power is set after thermal/electrical analysis.
RF-003	Isolator / circulator	Protects the source, absorbs or redirects reflected power, stabilizes the setup
RF-004	Directional coupler	Separately measures P_forward and P_reflected — the only way to know actual injected RF power
RF-005	50 Ω dummy load	Verifies the measurement chain produces no artificial signal when the cavity isn't excited
RF-006	RF coaxial cabling	50 Ω, known length, documented mechanical routing — not a mere accessory: cable routing can itself introduce a parasitic mechanical or electromagnetic force (cable "recoil" is flagged as an audit item)
RF-007	Cavity coupler	Magnetic loop, electric probe, iris, or waveguide. Position, area, offset, angle and coupling coefficient β must come from EM simulation, not be assumed.

3 · QPS core & the differential test

QC-001 — Resonant cavity: the electromagnetic heart of the prototype, characterized by f₀, Q₀, Qₗ, β, S₁₁ and the field distributions E(r), B(r). Simulation must identify the dominant mode before final fabrication.

QC-002 — QPS interaction region: currently the hypothetical part of the system. No new physics is assumed here — it is treated as an interchangeable module (configuration A, configuration B, or reference), which makes possible the single most important test in the program:

If the signal disappears when the module is swapped for a geometrically-equivalent dummy, that is a major experimental result on its own.

QC-003 — Reference element (mandatory in V1): same mass, same external geometry, same mounting, but deliberately different or controlled RF properties. Combined with the cavity and a dummy load, this yields four clean test conditions:

Test	Configuration
Test A	QPS module installed
Test B	Reference (twin) module installed
Test C	Cavity alone, no module
Test D	RF dummy load, cavity bypassed

This four-way comparison is far more powerful than a simple on/off thrust measurement.

4 · Thrust measurement system

ID	Component	Notes
MM-001	Force sensor	Measures F_meas(t). Exact choice depends on prototype mass and required sensitivity. A ~0.1 µN resolution is a target spec, not a guaranteed performance.
MM-002	Suspension	Torsion pendulum or flexible mount, low friction, with known natural frequency f_mechanical and damping ratio ζ, both characterized
MM-003	Reference structure	Mechanically isolated from the bench as much as possible

4.1 · Defining and validating ΔF

ΔF is only a meaningful result if F_conventional and F_measured are each independently defined, and if the gap between them survives a real uncertainty budget. This is the part of the dossier a propulsion or instrumentation reviewer will check first.

F_conventional — the modeled baseline. Before anything is called anomalous, every known, non-exotic contribution that could load the sensor is estimated and summed:

• F_thermal — force-equivalent of structural expansion / center-of-mass shift, from the TH-001 ΔT(t) array and the structure's known CTE
• F_leakage — radiation pressure from any RF field leaking onto the enclosure, from SH-001 shielding effectiveness plus a leakage measurement with the cavity de-tuned
• F_cable — recoil / Lorentz force from current-carrying RF-006 cabling near the suspension, characterized with a cable-only excitation test (RF into the dummy load, cavity disconnected)
• F_vibration — apparent force from facility or pump-induced vibration, from ENV-001: F_vib = m·a
• F_buoyancy — convective/buoyancy loading in atmosphere, eliminated once V1.1's vacuum chamber (VAC-001) is in place
• F_magnetic — torque/force from ambient or induced magnetic fields, from ENV-003

F_measured — the raw reading. Read from MM-001, after deconvolving the MM-002 suspension's own mechanical transfer function, synchronized to the RF-004 forward/reflected power trace on the DAQ-002 common time base.

Uncertainty source	Type	Mitigation
Sensor noise / resolution	A (statistical)	Signal averaging, lock-in detection synced to RF chop frequency
Sensor calibration & linearity	B (systematic)	Traceable calibration via electrostatic comb actuator or calibrated micro-mass
Thermal drift	B	TH-001 array + subtraction of the modeled F_thermal(t)
Mechanical vibration	A/B	ENV-001 accelerometer-derived correction, vibration-isolated bench
RF leakage / EM coupling	B	SH-001 shielding + leakage characterized with cavity de-tuned
Cable coupling	B	Fixed, symmetric, damped routing; verified via dummy-load-only run
Environmental (pressure, B-field)	B	ENV-002/003 logging and subtraction
Calibration-standard traceability	B	Calibration source itself independently certified

Calibration & run procedure

1. Baseline / zero — Test D (dummy load, RF off): establish the noise floor and sensor offset over an extended quiet period.
2. Calibrated force injection — apply a known force (electrostatic comb or calibrated small mass) to confirm sensor gain and linearity in physical units.
3. Sham RF run — Test D at full RF power into the dummy load, identical cabling: isolates cable-recoil and RF-leakage artifacts before any module is installed.
4. Reference run — Test B (reference twin installed): sweep RF power (0–100 W) to build the F_conventional(P) curve for this exact geometry.
5. QPS run — Test A (QPS module installed): repeat the identical sweep and protocol.
6. Compute ΔF(P) = F_meas,A(P) − F_meas,B(P), propagate every uncertainty term above, and repeat the full A/B/C/D cycle across independent sessions.

Blind / sham protocol

• Module identity (QPS / reference / dummy) is concealed from the operator running the DAQ during a session; only an independent recordkeeper logs which configuration was tested
• Test order (A/B/C/D) is randomized per session to avoid time-correlated drift biasing one condition
• RF power level is randomized or blinded where feasible, decoded only at analysis time
• Analysis is run on blinded, anonymized datasets; the code is fixed before unblinding

Criteria for declaring a positive result — a candidate ΔF is only reported as a genuine anomaly if it:

• Exceeds the combined, pre-registered uncertainty budget by a stated margin (e.g. ≥ 5σ)
• Scales with RF input power in a physically consistent way
• Reproduces across independent runs, and ideally independent operators or labs
• Appears in Test A but vanishes (returns to the reference baseline) in Tests B, C and D
• Survives with the RF chain diverted into the dummy load as a final control
• Has been checked against every term in the F_conventional model, not just asserted to be "left over"

Anything short of this is, at best, a lead worth re-testing — not a result.

5 · Thermal instrumentation

TH-001 — thermocouples/RTDs at five minimum points: T1 cavity, T2 front flange, T3 rear flange, T4 support, T5 environment — tracking both T_i(t) and, critically, ΔT(t), since thermal expansion can become a significant contribution in V1. TH-002 — local RF hot-spot temperature sensor. TH-003 — passive dissipation or controlled cooling for V1; active thermal enclosure and tighter regulation deferred to V1.1.

6 · Environmental sensors

ID	Component	Purpose
ENV-001	Accelerometers	Measure a_x, a_y, a_z → estimate F_vib = m·a to quantify vibration contribution
ENV-002	Pressure sensor	Track air → reduced pressure → vacuum, to compare results in atmosphere vs. under vacuum (V1.1)
ENV-003	Magnetometer	Ambient magnetic field B_ambient(t)
ENV-004	EMI / electrical sensor	Characterizes RF and mains-borne disturbances

7 · Vacuum system — V1.1 option

VAC-001 vacuum chamber (target <10⁻⁴ mbar in the optimized V1.1 configuration, to cut convection, air movement and atmospheric thermal effects), VAC-002 vacuum pump sized to chamber volume, VAC-003 independent pressure gauge.

8–11 · Acquisition, power, shielding, safety

12 · Full V1 parts list

ID	Component	Subsystem	V1 status
MC-001	Cavity body	Mechanical	Essential
MC-002	Front flange	Mechanical	Essential
MC-003	Rear flange	Mechanical	Essential
MC-004	Structure / support	Mechanical	Essential
RF-001	RF source	RF	Essential
RF-002	RF amplifier	RF	Essential
RF-003	Circulator / isolator	RF	Recommended
RF-004	Directional coupler	RF	Essential
RF-005	50 Ω load	RF	Essential
RF-006	RF cables	RF	Essential
RF-007	Cavity coupler	RF	Essential
QC-001	Resonant cavity	QPS core	Essential
QC-002	QPS module	QPS core	Experimental
QC-003	Reference module	QPS core	Essential for validation
MM-001	Force sensor	Measurement	Essential
MM-002	Suspension	Measurement	Essential
MM-003	Reference structure	Measurement	Essential
TH-001	Temperature sensors	Thermal	Essential
TH-002	Local temperature sensor	Thermal	Recommended
TH-003	Thermal control	Thermal	Recommended
ENV-001	Accelerometers	Environment	Essential
ENV-002	Pressure sensor	Environment	V1.1
ENV-003	Magnetometer	Environment	Recommended
ENV-004	EMI sensor	Environment	Recommended
DAQ-001	Multichannel DAQ	Acquisition	Essential
DAQ-002	Synchronization	Acquisition	Essential
DAQ-003	ADC	Acquisition	Essential
PM-001	Main power supply	Power	Essential
PM-002	Instrumentation supply	Power	Essential
SH-001	RF shielding	Shielding	Essential
SH-002	Magnetic shielding	Shielding	Recommended
SH-003	Experimental enclosure	Environment	V1.1
VAC-001	Vacuum chamber	Vacuum	V1.1
VAC-002	Vacuum pump	Vacuum	V1.1
VAC-003	Pressure gauge	Vacuum	V1.1
SAF-001	RF interlock	Safety	Essential
SAF-002	Emergency stop	Safety	Essential
SAF-003	Electrical protection	Safety	Essential

13 · What to freeze now, what to leave open

Determine experimentally: f₀,meas, Q_meas, S₁₁, P_loss, T(t), F_meas(t) — closing, finally, on ΔF = F_meas − F_conventional with its full uncertainty budget.

Scientific references

• Shawyer, R. (2006). A Theory of Microwave Propulsion for Spacecraft. Satellite Propulsion Research Ltd — the original proposal for an asymmetric resonant-cavity microwave thruster.
• White, H. et al. (2016). Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum. Journal of Propulsion and Power, 33(4) — NASA Eagleworks tests.
• Kraft, T. et al. (2021). Thrust measurements of an asymmetric resonant-cavity thruster: a critical analysis. TU Dresden — the thermal-artifact refutation.
• Wilson, C.M. et al. (2011). Observation of the dynamical Casimir effect in a superconducting circuit. Nature, 479(7373) — first experimental confirmation.
• Lamoreaux, S.K. (1997). Demonstration of the Casimir force in the 0.6 to 6 µm range. Physical Review Letters, 78(1).
• Casimir, H.B.G. (1948). On the attraction between two perfectly conducting plates. Proc. Royal Netherlands Academy of Arts and Sciences, 51.
• Jackson, J.D. (1999). Classical Electrodynamics, 3rd ed. Wiley.
• Pozar, D.M. (2012). Microwave Engineering, 4th ed. Wiley.

Glossary

Resonant cavity

A metal enclosure in which electromagnetic waves oscillate at frequencies set by its geometry.

Casimir effect

An attractive force between two parallel conducting surfaces caused by quantum vacuum fluctuations.

Quality factor (Q)

The ratio of stored energy to energy dissipated per cycle in a resonant system.

Specific impulse (Isp)

The duration a thruster can deliver thrust equal to the weight of its consumed propellant.

MEMS

Micro-Electro-Mechanical System — a micro-scale mechanism made by photolithography.

Superconductor

A material with zero electrical resistance below a critical temperature.

Conclusion

What's realistic: photon radiation pressure is a real, demonstrated phenomenon already used in solar sails and laser propulsion; resonant-cavity electromagnetics and the Casimir effect are well-established and measurable; quantum materials are a maturing, promising technology. None of that, by itself, proves NOAH-QPS produces net thrust.

What remains a challenge: any real thrust here is expected to be very small and would demand a heavy cryogenic system to operate; system complexity (vacuum, cryogenics, control) is extreme; He3 cost and maintenance are prohibitive for most applications; and — per TU Dresden's experience with the EmDrive — thermal drift, center-of-gravity shift, and cable coupling can all mimic thrust in a poorly-controlled test rig. That is precisely why the V1 differential architecture (QPS module vs. reference twin vs. dummy load) exists.

NOAH-QPS is not a perpetual-motion engine, a violator of momentum conservation, or an unlimited energy source. It is a spacecraft propulsion concept grounded in real physics, a serious engineering challenge, and a contribution to research on quantum effects relevant to gravity.