---
id: qcw-operation
title: "QCW Operation: Driven Leader Growth Through Sustained Energy Injection"
status: established
source_sections: "spark-physics.txt: Part 5 (lines 281-361), Part 9 (lines 666-700); Phase 6 QCW community survey (2026-02-10)"
related_topics: [thermal-physics, streamers-and-leaders, coupled-resonance, power-optimization, energy-and-growth, capacitive-divider, branching-physics, field-thresholds, empirical-scaling, equations-and-bounds, open-questions]
key_equations:
  - "Growth rate: dL/dt = P_stream / epsilon"
  - "Driven leader step time: step_time ~ step_length / growth_rate"
  - "Conductance relaxation: dG/dt = (G_st(i) - G) / tau_g"
  - "Thermal diffusion: tau_thermal = d^2 / (4 * alpha)"
key_terms:
  - "QCW"
  - "sword_spark"
  - "driven_leader"
  - "burst_ceiling"
  - "frequency_threshold"
  - "thermal_ratcheting"
  - "conductance_relaxation"
  - "ramp_duration"
  - "pulse_skip"
images:
  - qcw-vs-burst-timeline.png
examples:
  - spark-growth-timeline.md
open_questions:
  - "No direct arc current measurement on any QCW coil — the actual current flowing through the spark channel during QCW growth is unknown"
  - "No spectroscopic temperature measurement of QCW sparks — 5000 K is inferred from conductivity, not measured"
  - "No time-resolved impedance measurement during QCW ramp — the impedance trajectory during growth is unknown"
  - "No high-speed imaging correlated with electrical waveforms in QCW mode"
  - "No measurement of energy per unit length (epsilon) for QCW sparks — can only be bounded from total input energy and estimated system efficiency"
  - "Voltage gradient in TC sparks disputed — Uspring estimates 1.5 kV/cm, Barnkob estimates 3 kV/cm"
  - "No systematic frequency sweep study — same coil tested at 100, 200, 300, 400 kHz to isolate frequency effect"
---

# QCW Operation: Driven Leader Growth Through Sustained Energy Injection

QCW (Quasi-Continuous Wave) is a Tesla coil operating mode that produces straight "sword" sparks dramatically longer than burst-mode DRSSTCs of comparable size. Where burst mode relies on high instantaneous voltage (200-600 kV) to push streamers outward in a single shot, QCW uses sustained low-voltage energy injection (40-70 kV) over 10-22 ms to grow a thermally persistent leader channel at ~170 m/s. This document consolidates all QCW-specific physics, measurements, and design parameters from the community research survey and framework analysis.

The key insight: **QCW sparks grow because the leader channel persists between RF cycles and conducts energy to the tip, not because the voltage is high enough to bridge the gap.** This is a fundamentally different growth mechanism from burst mode, and it explains why QCW achieves 7-16x spark:secondary ratios compared to 2-4x for burst DRSSTCs.

## 1. The QCW Parameter Space

QCW occupies a distinct region in Tesla coil design space, differing from burst-mode DRSSTCs in every major parameter:

| Parameter | QCW Range | Burst DRSSTC | Source |
|-----------|-----------|--------------|--------|
| Coupling (k) | 0.3-0.55+ | 0.05-0.2 | Build survey |
| Operating frequency | 300-600 kHz | 50-110 kHz | Build survey |
| Tank capacitance | 5-15 nF | 50-300 nF | Build survey |
| Ramp duration | 10-22 ms | N/A (burst ~70-150 us) | Build survey |
| Peak primary current | 50-200 A | 200-1000+ A | Build survey |
| Secondary voltage | 40-70 kV | 200-600 kV | Ward, davekni |
| Spark:secondary ratio | 7-16x | 2-4x | Build survey |
| Growth rate | ~170 m/s | N/A (single-shot) | HVF estimate |

### 1.1 The 15:1 Voltage Ratio

The single most important quantitative comparison in the dataset: davekni measured **~600 kV for 2-3 m burst sparks vs ~40 kV for equivalent QCW sparks** at 450 kHz. This 15:1 voltage ratio proves that QCW growth is driven by sustained energy injection, not high instantaneous voltage. Multiple independent builders confirm the low QCW voltage (Steve Ward: 40-55 kV; Loneoceans: 50-70 kV). [Phase 6 QCW community survey]

**Physical explanation:** The leader formation voltage threshold of 300-400 kV [Bazelyan & Raizer 2000] applies to **single-shot impulses** where the entire streamer-to-leader transition must occur from one event. In QCW, the thermal ratcheting mechanism (see Section 3) accumulates energy from thousands of RF cycles, crossing the critical temperature thresholds (2000 K -> 4000 K -> 5000 K) without ever requiring high instantaneous voltage. The voltage merely needs to exceed the inception threshold and maintain current flow. See [[streamers-and-leaders]] for details.

### 1.2 Coupling Requirement: k >= 0.3

All successful QCW sword-spark builds use k >= 0.3:

| Builder | k | Spark:secondary ratio | Notes |
|---------|---|----------------------|-------|
| Loneoceans v1.0 | 0.32-0.35 | 7.3:1 | Initial |
| Loneoceans v1.5 (first) | 0.306 | — | Insufficient — breakthrough came at 0.38 |
| Loneoceans v1.5 (final) | 0.38 | 13:1 | Breakthrough |
| Loneoceans QCW2 | 0.365 | 10:1 | |
| flyglas | 0.391 | ~12:1 | |
| Lucasww | 0.44 | 10:1 | |
| Dr. Kilovolt (Jan Martis) | 0.55 | — | SiC PSFB, 2-2.5 m sparks |
| davekni | 0.71 | — | Ferrite-assisted, highest documented |
| Standard DRSSTC | 0.05-0.20 | 2-4:1 | For comparison |

Higher coupling enables sufficient power transfer at QCW's lower peak currents (50-200 A vs 200-1000+ A for burst). It also widens pole separation, making frequency tracking more robust (see [[coupled-resonance]]). However, Loneoceans' SSTC3 (single-resonant, lower coupling) still produces straight sparks at 380-420 kHz, suggesting k >= 0.3 is an **engineering constraint** (adequate power delivery) rather than a **physics constraint** (straightness).

## 2. The Sword Spark Mechanism

### 2.1 Frequency Threshold: 300-600 kHz

Six or more independent builders have converged on a frequency range for producing straight sword sparks:

| Observer | Observation | Source |
|----------|-------------|--------|
| Mads Barnkob | "Sword characteristic shows above 400 kHz" | HVF |
| LabCoatz (Zach Armstrong) | Below 300 kHz: "chaotic and less straight"; above 600 kHz: "more curvy" | Hackaday |
| Kaizer DRSSTC IV | QCW at ~100 kHz: "swirling" sparks, NOT straight | HVF |
| Fat Coil builder | "Above 350 kHz, plasma exhibits growth in straight segments" | TCML |
| Loneoceans SSTC3 | Straight sparks at 380-420 kHz | loneoceans.com |
| Multiple QCW builders | All successful sword-spark builds operate 300-500 kHz | Build survey |

### 2.2 Why Frequency Matters: RF Period vs Thermal Time Constants

The physical mechanism is the ratio between the RF half-period and the streamer thermal diffusion time:

```
At 400 kHz: RF half-period = 1.25 us
Streamer tau_thermal (d = 100 um) = d^2 / (4*alpha) ~ 125 us

Ratio: tau_thermal / T_RF = 125 / 1.25 = 100x
```

The channel experiences **effectively continuous heating** with negligible cooling between RF half-cycles. The conductance relaxation time constant (tau_g = 40 us for heating, see [[thermal-physics]]) spans ~16 RF cycles at 400 kHz, ensuring smooth, monotonic conductance increase.

At 50-100 kHz (half-period 5-10 us), thinner streamers (10-50 um, tau ~ 1-30 us) experience significant cooling between cycles. The preferred conductive path diffuses and branches — the channel cannot maintain a single straight track.

At >600 kHz, "curvy" sparks are observed. This may relate to skin effect, displacement current dominance, or switching artifacts at extreme frequencies.

**Quantitative prediction:** At frequency f, the Joule heating rate scales as ~f (more half-cycles per unit time at the same peak current). A channel at 400 kHz receives ~4x more thermal energy per millisecond than at 100 kHz.

### 2.3 Pulse-Skip Modulation Does Not Produce Full Sword Sparks

Multiple experimenters (Steve Ward, Steve Conner, others circa 2011) tried pulse-skip approaches to achieve QCW-like behavior and could not produce full sword sparks.

Steve Ward: Sword sparks need "relatively smooth/continuous modulation of the spark power with little ripple." If the coil stores enough energy to smooth out the missing pulses, "it's probably massively overbuilt."

**What pulse-skip actually does:** In a DRSSTC, pulse-skip is a bridge current-limiting method. During "skip" cycles, one GDT (gate drive transformer) is inverted so the H-bridge effectively shorts the primary tank (single-leg inhibit / "freewheeling"), or both bridge halves shut down and energy returns to the bus caps. The IGBTs continue switching synchronized to secondary current feedback — phase coherence is maintained and there is no phase discontinuity when active drive resumes. Primary current does not drop to zero; it decays gradually through the loaded Q of the resonant system. The resulting current envelope is a sawtooth bounded by the OCD (overcurrent detection) threshold — current rises to the limit, bridge freewheels until current decays, then drive resumes. [Steve Ward DRSSTC design guide; UD+ documentation (P. Slawinski); UD3 (Netzpfuscher)]

**Why it doesn't produce full swords — envelope quality:** The sawtooth current envelope at a fixed OCD threshold delivers approximately constant average power, not the smoothly ramping power profile that QCW requires. True QCW uses a linear voltage ramp, which produces a quadratic power envelope (P ~ V^2) — the natural profile for growing a spark against increasing capacitive loading. Pulse-skip cannot easily produce this quadratic profile. The per-cycle current jitter from the on-off-on switching pattern, even with optimal distribution of skip events, creates enough power envelope ripple to prevent clean single-channel dominance. [Loneoceans QCW documentation; HVF topic 292]

**It's a continuum, not binary:** The effect of envelope quality on spark straightness is progressive. Coarse pulse-skip at a fixed OCD threshold produces standard branchy DRSSTC sparks. A more sophisticated Bresenham-algorithm pulse-density modulation creating a linear ramp envelope produces sparks that are noticeably more sword-like but still branch — an intermediate result. True analog QCW with a smooth quadratic power envelope produces full swords. The evidence suggests that spark straightness improves continuously with envelope smoothness, with no sharp threshold.

**Smooth topologies that work:** Steve Ward's original linear voltage ramp (giving quadratic power), Dr. Kilovolt's SiC Phase-Shifted Full Bridge (inherently smooth with a "1-cosine" transfer function), and Loneoceans' SSTC3 staccato approach (using the rising AC mains waveform as a natural voltage ramp) all produce straight sparks because they deliver smooth, continuously ramping power without per-cycle jitter.

**Note:** Pulse-skip (bridge current control) is distinct from staccato (interrupter timing synchronized to AC mains). They serve different functions and can be combined. Staccato provides a natural voltage ramp over ~4-5 ms per mains half-cycle; pulse-skip manages current limits within each burst.

## 3. The Driven Leader Growth Model

### 3.1 Growth Rate: ~170 m/s

QCW sparks grow at approximately half the speed of sound. This is estimated from community observations of spark growth during QCW ramps. [Phase 6 QCW survey, HVF topic 973]

**Self-consistency check:** At 170 m/s over a 10 ms ramp, the spark grows 1.7 m. Over a 20 ms ramp, 3.4 m. These match observed QCW spark lengths (1-2 m for standard builds, 3.35 m for the Fat Coil).

This velocity is intermediate between free streamers (~10^6 m/s) and natural lightning leaders (~10^4 m/s for stepped leaders, averaged). It represents a **driven leader** propagation mode unique to QCW: the leader advances continuously, fed by the circuit, at a rate limited by the thermal conversion of streamer-to-leader at the tip.

### 3.2 Step Time Derivation from tau_g

From the growth rate and Bazelyan's typical leader step length (~1 cm):

```
step_time = step_length / growth_rate = 0.01 m / 170 m/s ~ 60 us
```

This 60 us step time is close to the conductance relaxation heating time constant (tau_g = 40 us from Bazelyan). The channel needs approximately one tau_g to heat each new segment to leader temperature. The 1.5x ratio (60 us vs 40 us) is reasonable given that the transition also requires crossing the eta_T efficiency bottleneck (10% heating efficiency at ambient → 100% above 2000 K). See [[thermal-physics]] for the full conductance relaxation model.

### 3.3 Contrast with Bazelyan Leader Velocity

The Bazelyan formula v_L = 1500*sqrt(|Delta_U_t|) gives ~4.7-8.2 km/s at 100-300 kV — 25-50x faster than the observed 170 m/s QCW growth rate. The discrepancy is explained by the fundamental difference between:

- **Bazelyan's v_L**: Instantaneous leader step velocity (the speed of thermal instability contraction within a single step)
- **QCW 170 m/s**: Net growth rate averaged over many steps including the time to heat each new streamer segment

The QCW leader advances in rapid micro-steps at ~km/s but spends most of its time waiting for each new segment to thermalize. See [[streamers-and-leaders]] for details.

### 3.4 Thermal Ratcheting Mechanism

The 5:1 asymmetry in conductance relaxation time constants creates a one-way thermal ratchet:

```
tau_g = 40 us   (channel heating — current rising)
tau_g = 200 us  (channel cooling — current falling)
```

[Bazelyan & Raizer 2000, Ch 4, pp. 194-195]

Over many RF cycles:
1. During the high-current half-cycle: conductance increases toward G_st(i_peak) with tau_g = 40 us
2. During the low-current half-cycle: conductance decreases toward G_st(0) = 0 with tau_g = 200 us
3. **Net effect:** Conductance ratchets upward over ~10-50 RF cycles (50-250 us at 200 kHz)

This is the microsecond-timescale mechanism underlying the millisecond-timescale streamer-to-leader transition. Each RF cycle deposits a net conductance increment, accumulating over thousands of cycles during the QCW ramp.

## 4. Three Ramp Regimes

Loneoceans documented three distinct outcomes through controlled variation of ramp duration (QCW v1.5):

| Ramp Duration | Visual Result | Physics Interpretation |
|---------------|--------------|----------------------|
| Too short (<5 ms) | "Gnarly, segmented sparks" | Insufficient time for leader transition; disconnected leader segments don't merge |
| Optimal (~10-20 ms) | Straight sword sparks | Leader forms within first few ms; grows continuously for remainder |
| Too long (>25 ms) | "Really hot and fat but bushy" | Leader reaches voltage-limited L_max; excess energy drives branching |

### 4.1 The "Too Long" Regime

Once the leader reaches its maximum length (set by the [[capacitive-divider]]), additional energy cannot extend it further. The leader channel becomes very hot and thick, increasing C_sh and worsening voltage division. The excess power must dissipate somewhere — lateral breakouts from the superheated leader trunk become the path of least resistance.

### 4.2 The "Too Short" Regime

Ramps shorter than ~5 ms don't allow the full streamer-to-leader transition (which requires ~0.5-2 ms from [[streamers-and-leaders]]). The "segmented" appearance suggests the spark advances as disconnected leader segments that don't merge into a continuous trunk. This is consistent with the thermal ratcheting model requiring multiple dark period cycles — see [[thermal-physics]].

### 4.3 QCW Timing Analysis

Typical optimal QCW ramp: 12 ms at 400 kHz

- **0-2 ms**: Voltage builds toward inception. Possible aborted leader attempts. High epsilon.
- **2-4 ms**: Streamers form and begin heating. Transition zone. Temperature crosses critical thresholds at base.
- **4-8 ms**: Leader trunk established. Low-resistance channel conducts energy to tip. Epsilon falling as thermal accumulation helps.
- **8-12 ms**: Leader-dominated growth. Streamer crown at tip continuously fed by leader current. Best epsilon (5-8 J/m). Growth slowing as [[capacitive-divider]] attenuates V_tip.

## 5. The Burst Ceiling: Why QCW Is Necessary

### 5.1 Steve Ward's 80 us Measurement

Steve Ward's DRSSTC-0.5 provides a clean measurement of burst-mode growth saturation:

| ON Time | Spark Length | Input Power |
|---------|-------------|-------------|
| ~70 us | 10-18 inches | 33-180 W |
| >80 us | **No additional length** | Diminishing returns |

"Gained almost no spark length after about 80 us of ON period." [Steve Ward, stevehv.4hv.org/DRSSTC.5.htm]

### 5.2 Thermal Physics Explanation

The 80 us ceiling is strikingly consistent with the thermal time constant for 100 um streamers:

```
tau_thermal = d^2 / (4*alpha) = (100e-6)^2 / (4*2e-5) ~ 125 us
```

After approximately one thermal time constant, channels are cooling as fast as they are being heated. Additional energy goes into re-heating decaying channels rather than new forward growth. This is the fundamental wall that QCW overcomes by sustaining drive beyond this timescale.

### 5.3 Steve Conner's Burst Efficiency Finding

Short bursts of high peak power grow sparks more efficiently than long bursts of low peak power. A 100 us burst works better than 150 us at the same total energy. Higher peak power pushes the initial streamer further before the 80 us ceiling hits. See [[power-optimization]].

## 6. QCW Energy Budget

### 6.1 Measured Energy Data

| Quantity | Value | Source |
|----------|-------|--------|
| QCW energy per pulse | 275 J (for 1.78 m) | Loneoceans v1.5 |
| Apparent epsilon (total input / length) | 155 J/m | Derived |
| Estimated system efficiency | 30-50% | Community consensus |
| Estimated spark epsilon | 45-75 J/m | Derived (155 * 0.3-0.5) |
| Burst DRSSTC energy per bang | 5-12 J | Steve Ward |
| Burst DRSSTC average power | 33-180 W for 25-46 cm | Steve Ward DRSSTC-0.5 |

The apparent epsilon of 155 J/m includes system losses (primary resistance, secondary losses, corona, radiation). The spark epsilon of 45-75 J/m includes the early inefficient growth phase (first ~2-4 ms at high epsilon). The leader-dominated late-stage epsilon is significantly lower (estimated 5-15 J/m), consistent with the framework's QCW range.

### 6.2 Frequency Tracking During QCW Ramp

Loneoceans measured frequency shifts during QCW operation:

| Condition | Frequency | Shift |
|-----------|-----------|-------|
| Unloaded secondary | 406-409 kHz | baseline |
| With 50 cm simulated streamer | 349 kHz | -14% |
| With 1 m simulated streamer | 310 kHz | -24% |
| QCW v1.5 during actual spark | 413 → 377 kHz | -8.7% |

The 8.7% shift during actual QCW operation is less than the simulated 1 m streamer (-24%), suggesting a real 1.78 m spark has lower effective capacitance than a solid wire — consistent with the branched, non-solid nature of real sparks. Frequency tracking (PLL or programmed) is essential during QCW ramps; a 5% detuning costs ~50% of delivered power (see [[coupled-resonance]]).

## 7. Environmental and Design Factors

### 7.1 Environmental Sensitivity

davekni observed straighter arcs in warm, dry conditions; curved/branchy arcs more common outdoors (cooler, more humid). Dr. Kilovolt reported "looping" or "curving" streamers under humid or cool outdoor conditions.

**Physics:** Higher humidity → faster complex-ion recombination (25x for hydrated ions, see [[streamers-and-leaders]]) → shorter plasma lifetime → less thermal persistence → more branching. Lower temperature → higher gas density → higher E_propagation → harder to sustain growth in single channel.

### 7.2 Smooth Power Delivery Topologies

Successful QCW implementations use inherently smooth power delivery:

- **Steve Ward's quadratic ramp**: Voltage rises linearly → power rises as V^2 → smoothly increasing energy delivery
- **Phase-Shifted Full Bridge (PSFB)**: Dr. Kilovolt's SiC PSFB provides a "1-cosine" transfer function with no pulse-skip artifacts
- **UD3 controller**: Netzpfuscher's phase-shift modulation design provides smooth QCW control
- **Analog ramp generators**: Finn Hammer's reference design for linear voltage ramp

Pulse-skip modulation produces more sword-like sparks than standard burst but falls short of true swords due to envelope jitter (Section 2.3).

## 8. Spark-to-Secondary Ratios: The Efficiency Measure

The spark:secondary ratio (spark length divided by secondary winding length) is the clearest measure of QCW's advantage:

| Builder | Mode | Spark | Secondary | Ratio |
|---------|------|-------|-----------|-------|
| Steve Ward | Burst | 80" | 22" | 3.6:1 |
| Loneoceans DRSSTC3 | Burst | 70" | 27.5" | 2.5:1 |
| Loneoceans QCW v1.0 | QCW | 40" | 5.5" | 7.3:1 |
| Lucasww | QCW | 51" | 5" | 10.2:1 |
| Loneoceans QCW2 | QCW | 24" | 2.4" | 10:1 |
| Loneoceans QCW v1.5 | QCW | 70+" | 5.55" | 12.6:1 |
| Mathieu thm | QCW | 76" | 5.6" dia | 13.6:1 |
| Fat Coil | QCW | 132" | 8" | 16.5:1 |

The 3-5x improvement from burst to QCW is a direct measure of the leader-dominated growth advantage. Leaders extend the effective electrode continuously, so the secondary length (which constrains maximum voltage) becomes less important relative to sustained power delivery.

## 9. Critical Time Comparisons

| Timescale | Value | Significance |
|-----------|-------|-------------|
| RF half-period at 400 kHz | 1.25 us | Channel heating between cycles |
| RF half-period at 100 kHz | 5 us | Channel heating between cycles |
| Streamer tau_thermal (100 um) | ~125 us | 100x longer than RF period at 400 kHz |
| Conductance tau_g (heating) | 40 us | Time to heat one "step" |
| Conductance tau_g (cooling) | 200 us | 5x longer than heating → ratcheting |
| Driven leader step time | ~60 us | Close to tau_g; sets growth rate |
| Burst pulse duration | 70-150 us | Comparable to streamer tau → saturation |
| Burst ceiling (Ward) | ~80 us | Streamer growth saturates |
| Leader transition time | 0.5-2 ms | Within QCW ramp; exceeds burst pulse |
| Streamer persistence | 1-5 ms | Exceeded by QCW ramp |
| Dark period cycle | 1-5 ms | Multiple cycles fit within QCW ramp |
| QCW ramp duration | 10-22 ms | 100x longer than tau_g |

## 10. Community Hypotheses (Unproven)

### 10.1 Uspring's Sideways Breakout Suppression

QCW's slowly ramped voltage keeps tip voltage low, reducing the transverse field component. The field is only strong enough for forward propagation along the existing hot channel.

**Assessment:** Physically plausible. The hot leader channel has much lower impedance than virgin air to the side, so a weak field preferentially drives current forward.

### 10.2 Channel Temperature: ~5000 K

Uspring estimated ~5000 K from conductivity analysis. Not spectroscopically measured. Consistent with Bazelyan's leader temperature range (4000-6000 K) and the white/yellow visual appearance of QCW sword sparks (blackbody peak near 5000 K).

### 10.3 Steve Ward's "2000 Small Sparks" Model

At 400 kHz over 5 ms, there are ~2000 RF half-cycles, each depositing a small amount of energy. This is a simplified but correct description of the driven-leader mechanism as viewed through the conductance relaxation model.

## 11. Framework Validation Summary

| Prediction | Community Data | Agreement |
|------------|---------------|-----------|
| Thermal persistence is key to QCW advantage | Confirmed by all data | Excellent |
| Streamer-to-leader transition requires sustained drive | Confirmed | Excellent |
| Capacitive voltage division limits length | Confirmed by frequency shift data | Excellent |
| Hungry streamer self-optimization | Confirmed by Burnett causality insight | Excellent |
| Burst mode limited by streamer cooling | Ward: 80 us ceiling (cf. tau ~ 125 us) | Good (within 1.5x) |
| Optimal QCW ramp: >5x tau_thermal | 10-20 ms (well above minimum) | Consistent |

### What the Framework Missed

1. **Frequency threshold for sword sparks (300-600 kHz)** — derivable from existing thermal physics (RF period << tau_thermal) but was not explicitly predicted
2. **QCW secondary voltage is low (40-70 kV)** — framework implicitly assumed higher voltages for longer sparks
3. **Power envelope quality matters** — growth model dL/dt = P/epsilon does not capture the effect of envelope smoothness on channel selection; spark straightness improves progressively from pulse-skip (sawtooth) through Bresenham PDM (linear ramp) to true QCW (quadratic ramp)
4. **Three ramp regimes** — the "too long" bushy regime was not predicted (arises from capacitive divider saturation + excess power branching)
5. **QCW growth rate (~170 m/s)** — not previously predicted but derivable from tau_g and step length

## 12. Key Persons

| Person | Contribution |
|--------|-------------|
| Steve Ward | QCW inventor; quadratic power profile; 40-55 kV measurement; 80 us burst ceiling |
| Gao Guangyan (Loneoceans) | Most detailed QCW measurements (4 builds); frequency tracking data; three ramp regimes |
| David Knierim (davekni) | Critical 15:1 voltage comparison; oversized QCW; fiber probe |
| Richie Burnett | Causality reversal; pole splitting theory |
| Steve Conner | Burst efficiency finding; hungry streamer principle |
| Uspring | Temperature estimates (~5000 K); voltage gradient analysis |
| Jan Martis (Dr. Kilovolt) | SiC PSFB QCW; k=0.55; 2-2.5 m sparks; environmental sensitivity |
| Mads Barnkob | Frequency threshold observation (>400 kHz) |
| Zach Armstrong (LabCoatz) | Frequency window (300-600 kHz) |

## Key Relationships

- **Derives from:** [[thermal-physics]] (thermal persistence, conductance relaxation, tau_g asymmetry are the physical foundation)
- **Derives from:** [[streamers-and-leaders]] (driven leader growth is a special case of the streamer-to-leader transition)
- **Interacts with:** [[coupled-resonance]] (frequency tracking during QCW ramp is essential; pole shifts 5-25%)
- **Interacts with:** [[power-optimization]] (R_opt_power shifts continuously during ramp; match at 50-70% of target length)
- **Interacts with:** [[capacitive-divider]] (voltage division limits maximum length; causes "too long" regime)
- **Interacts with:** [[energy-and-growth]] (epsilon varies during ramp from ~15 J/m early to ~5-8 J/m late)
- **Constrained by:** [[field-thresholds]] (inception threshold must be exceeded; propagation threshold sustains growth)
- **Measured via:** Phase 6 QCW community survey (primary data source)