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industrial data rf cable series20 kV – 100 kV DC / Pulse≤ 35–80 nH/m Low InductanceDual Semicon Corona-Free Screens

NEGACOAX High-Voltage Low-Inductance Pulse Discharge Coaxial20–100 kV low-inductance (35–80 nH/m) semicon-screened pulse discharge coaxial cable

High-voltage low-inductance (35–80 nH/m) pulse-discharge coaxial cable (NEGACOAX) for capacitor banks, lasers, and plasma physics with a finely stranded copper core, semiconductive layers, corona-free EPR/FEP dielectric (20–100 kV DC), and heavy braid.

Low-EMC design
EMC screen
Oil-resistant
Flame-retardant
Order designation
NEGACOAX 40kV-20Ω
Outer Ø ≈
22.50 mm
Wall thickness
5.00 mm
Total weight ≈
610.0 kg/km
Min. bend R (fixed)
180 mm
All sizes (8)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Pulse voltage
20 to 100 kV
DC charge & fast-rise discharge
Inductance
35 to 80 nH/m
Ultra-low loop inductance
Impedance
15 Ω to 50 Ω
Matched to PFN & Marx banks
Stress control
Dual semicon
Co-extruded inner/outer semicon
Peak current
Up to 150 kA
High dI/dt capacitor discharge
Partial disch.
< 5 pC
Corona-free per IEC 60270

Typical values for this cable type, based on IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax — confirmed in the datasheet and quotation for your order.

Application fit

Is NEGACOAX right for your machine?

Specify NEGACOAX for pulsed-power capacitor banks, Marx generators, flashlamp/excimer lasers, electromagnetic forming coils, Z-pinch fusion experiments, and klystron modulators.

Fixed installation

Suitable

Co-extruded inner/outer semicon layers eliminate micro-void ionization and partial discharge (< 5 pC) up to 100 kV.

VFD inverter to AC motor screened feeder

Suitable

Symmetric coaxial return current in the heavy outer braid cancels external magnetic fields (35–80 nH/m inductance).

Switchgear & control cabinet wiring

Suitable

Flexible EPR-insulated versions bend down to 8 × OD inside compact pulsed-laser modulators and medical lithotripter cabinets.

Motorised monospiral reel

Not suitable

High-voltage pulsed-power transmission lines are designed for fixed laboratory and modulator routing, not reeling drums.

Use HELIFLEX High-Power Feeder
Typical machinesPulsed-Power Capacitor Banks & PFNsHigh-Energy Flashlamp & Excimer LasersParticle Accelerator Klystron ModulatorsElectromagnetic Forming & MagnetizingPlasma Physics & Fusion Research Labs

Construction

Layer by layer

Corona-free HV pulse coax: flexible rope-lay or annular copper core, inner semiconductive stress layer, HV EPR/LDPE dielectric, outer semiconductive layer, heavy copper braid, and PVC/PUR sheath.

123456
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Flexible stranded or annular copper center conductorFine-stranded tinned copper rope-lay or flexible core-over-spiral conductor (6 mm² to 50 mm²)Maximises surface periphery to lower characteristic impedance and inductance (nH/m)
2Inner semiconductive stress-grading screenCo-extruded semiconductive EPR or polyolefin layer bonded over the conductor strandsSmooths strand electric-field gradients and prevents corona inception up to 100 kV
3High-voltage EPR or Virgin LDPE pulse dielectricVoid-free flexible ethylene propylene rubber (EPR) or high-purity low-density PEWithstands 20–100 kV DC charging and fast nanosecond/microsecond voltage reversal
4Outer semiconductive dielectric screenExtruded/taped semiconductive elastomer layer under the metallic return braidPrevents air-gap partial discharge between the dielectric and return braid wires
5Heavy-duty tinned copper return braidHigh-cross-section tinned copper wire braid (≥ 95 % coverage) + copper equalizing tapeCarries 10–150 kA peak discharge current and resists radial magnetic hoop forces
6Flame-retardant PVC, PUR or Chloroprene jacketHeavy-duty red or black oil- and abrasion-resistant outer sheathMechanical containment against repulsive magnetic pulse shock

NEGACOAX 25kV – 40kV (Low-L 15–25 Ω)

Ultra-low inductance (35–55 nH/m) flexible EPR pulse coax for flashlamp lasers and magnetizers

NEGACOAX 60kV – 100kV (30–50 Ω)

Heavy-wall semicon-screened EPR/PE coaxial feeder for Marx generators and capacitor banks

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax. Values for your order are confirmed in the datasheet and quotation.

Electrical

Rated DC / pulse voltage
20 kV, 30 kV, 40 kV, 60 kV, 80 kV & 100 kV
Characteristic impedance
15 Ω, 20 Ω, 28 Ω, 40 Ω or 50 Ω (by geometry)
Distributed loop inductance
35 nH/m (15 Ω) to 80 nH/m (40–50 Ω)
Distributed capacitance
140 pF/m to 360 pF/m
Partial discharge level
< 5 pC at 1.5 × nominal AC voltage (IEC 60270)
Peak pulse current capacity
25 kA to 150 kA (depending on model)

Thermal

Operating temperature (EPR)
-40 °C to +90 °C continuous
Operating temperature (LDPE)
-30 °C to +70 °C continuous
Short-circuit conductor temp.
+200 °C max. (EPR dielectric)

Mechanical

Overall cable diameter
13.5 mm (20 kV) to 38.0 mm (100 kV)
Min. bending radius
8 × OD (fixed EPR) · 12 × OD (HV LDPE)
Return braid coverage
≥ 95 % tinned copper braid + binder tape

Resistance

Corona & ozone resistance
Semicon-screened EPR immune to ozone cracking
Flame & oil resistance
IEC 60332-1-2 & EN 60811-404 oil resistant
Voltage reversal endurance
Up to 50 %–80 % ringing voltage reversal

Reference standards

Partial discharge test
IEC 60270 / IEEE 404 HV Dielectric Screening
Legacy HV coax cross-ref
Upgrades RG-217, RG-218, RG-220 & YK-198
RoHS & REACH
RoHS 3 & REACH SVHC compliant

Identification

Outer sheath colour
Red (high-voltage warning) or Black
Surface legend
TEBAOFLEX NEGACOAX HIGH VOLTAGE LOW INDUCTANCE PULSE COAX
Customs tariff (HS)
8544.60

Sizes

8 standard configurations (NEGACOAX)

Engineering dimensions, impedance, propagation velocity, and electrical ratings for NEGACOAX per IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax.

Dimensions & weights
Order designationImpedance / sizeConductor & dielectricWall ≈
mm		Outer Ø ≈
mm		Metal
kg/km		Weight ≈
kg/km		Min. bend R
fixed mm		Enquiry
Standard NEGACOAX configurations
NEGACOAX 20kV-15Ω20 kV · 15 Ω (35 nH/m)Hollow Core + Semicon EPR2.8014.50165.0295.0116
NEGACOAX 25kV-20Ω25 kV · 20 Ω (45 nH/m)Hollow Core + Semicon EPR3.4016.80195.0365.0135
NEGACOAX 30kV-28Ω30 kV · 28 Ω (58 nH/m)16 mm² Cu + Semicon EPR4.2019.20230.0450.0154
NEGACOAX 40kV-20Ω40 kV · 20 Ω (42 nH/m)Annular Cu + Semicon EPR5.0022.50310.0610.0180
NEGACOAX 40kV-40Ω40 kV · 40 Ω (75 nH/m)16 mm² Cu + Semicon EPR5.2021.80250.0540.0175
NEGACOAX 60kV-30Ω60 kV · 30 Ω (62 nH/m)25 mm² Cu + Semicon EPR7.0027.50360.0820.0248
NEGACOAX 80kV-40Ω80 kV · 40 Ω (78 nH/m)25 mm² Cu + Semicon EPR9.0032.80420.01,120.0328
NEGACOAX 100kV-50Ω100 kV · 50 Ω (85 nH/m)35 mm² Cu + Semicon EPR11.2038.00510.01,480.0380
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • Outer diameters and weights are nominal engineering values for NEGACOAX subject to standard manufacturing tolerances per IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax.

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

  1. ConductorClass 5 stranding
  2. Spark test100 % in-line
  3. Lay-upCores, earth, fillers
  4. SheathingInner, braid / screen, outer
  5. Electrical testsAC voltage, resistance
  6. DimensionsOD, wall thickness
  7. Inspection documents & dispatchDrum & dispatch
Testing & inspectionTest value / referenceFrequency
Routine tests
Characteristic impedance, return loss (VSWR) & TDR sweep100 % frequency-domain return loss and TDR impedance verification per IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power CoaxEvery manufactured length
Dielectric spark & high-voltage withstand test100 % in-line spark and AC/DC dielectric withstand per IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power CoaxEvery spool or drum length
Sample tests
Insertion loss (attenuation), velocity & capacitance checkAttenuation (dB/100m), VoP (%), and capacitance within IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax limitsPer production batch
Screening attenuation, transfer impedance & environmental qualificationQualified to IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power Coax EMC shielding, thermal, and flame/fluid criteriaType qualification

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

IEC 60502-2 / IEEE 404 Semicon-Screened High-Voltage Pulsed-Power CoaxCE (2014/35/EU) & RoHS 3 (2015/863/EU) CompliantREACH SVHC Compliance Verified

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX NEGACOAX 40KV 20 OHM 42nH/m SEMICON PULSE DISCHARGE COAX
Delivery form
Export wooden drums, flange reels or precision coils
Standard lengths
100 m · 305 m · 500 m · 1000 m (or custom cut lengths)
MOQ
100 m (stock sizes) · 300–500 m (custom build)
Lead time
2–4 weeks ex-works
Incoterms
EXW, FOB, CIF, DAP

Technical documents

Downloads

PDFNEGACOAX High-Voltage Low-Inductance Pulse Discharge Coaxial – technical datasheet8 sizes · construction, technical data, approvalsXLSXNEGACOAX spec data (Excel)All 8 sizes with dimensions and data, for your BOM or quotation
Revision
2026-10-20
Updated
2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

Why do standard RF coaxial cables (such as RG-218 or RG-220) fail prematurely in high-voltage capacitor discharge service?
Standard RF coaxial cables place a braided wire shield directly over a solid polyethylene dielectric without semiconductive stress-control layers. Under 20–100 kV pulsed charging and ringing voltage reversals, microscopic air pockets under the braid ionize (corona / partial discharge), rapidly treeing and puncturing the PE insulation. NEGACOAX co-extrudes bonded inner and outer semiconductive layers to eliminate partial discharge (< 5 pC).
How does NEGACOAX achieve ultra-low inductance (35–55 nH/m)?
Coaxial inductance per unit length is proportional to ln(D/d), where D is the outer shield diameter and d is the inner conductor diameter. By enlarging the inner conductor diameter over a flexible support core while using a high-dielectric-strength EPR wall, the D/d ratio is minimized—cutting inductance to 35–55 nH/m and enabling faster pulse rise times (dI/dt).
Can several NEGACOAX cables be paralleled between a capacitor bank and load coil?
Yes. Paralleling N identical NEGACOAX cables divides the effective transmission-line inductance and impedance by N while multiplying peak current capacity (e.g., four 40 nH/m cables in parallel yield a 10 nH/m interconnect).
How are the semiconductive layers prepared during high-voltage termination?
At each cable end, the outer braid and outer semiconductive layer are stripped back to a defined stress-cone taper length (typically 150–400 mm depending on kV rating) so surface flashover and field concentration at the braid cutoff are prevented.

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NEGACOAX High-Voltage Low-Inductance Pulse Discharge Coaxial

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