Hollow Cathodes
Ground-based Hollow Cathode Plasma Electron Emitters (HCPEE)
EPL Manufactures four ground-based hollow cathode models, with steady state plasma electron emission current ratings up to 100 A. Gas choices include Xe, Kr, Ar, Ne, He, N2 and H2. All share common design and manufacturing heritage and offer mounting interface options. Custom HCPEE products above 100 A are also available.
Applications include ion beam neutralization, plasma source and plasma thruster discharge current and neutralization control, ion sputtering enhancement, substrate surface charge control, plasma volume neutralization, and stand-alone plasma generation. All hollow cathodes are supported by a complete system package which includes operating power systems, vacuum feed-throughs, and all in-vacuum and out-of-vacuum wiring and mounting connections for immediate customer use.

HCPEE 250
- Plasma electron flux: 0-10 A
- Electron energy: 1-2 eV (typical)
- Electron emission efficiency
(typical into plasma load): 1-3 A/sccm (Ar)
2-5 A/sccm (Xe) - Length: 2.7 inches

HCPEE 375
- Plasma electron flux: 0-25 A
- Electron energy: 1-2 eV (typical)
- Electron emission efficiency
(typical into plasma load): 1-3 A/sccm (Ar)
2-5 A/sccm (Xe) - Length: 4.0 inches

HCPEE 500
- Plasma electron flux: 0-50 A
- Electron energy: 1-2 eV (typical)
- Electron emission efficiency
(typical into plasma load): 1-3 A/sccm (Ar)
2-5 A/sccm (Xe) - Length: 5.5 inches

HCPEE 625
- Plasma electron flux: 0-100 A
- Electron energy: 1-2 eV (typical)
- Electron emission efficiency
(typical into plasma load): 1-3 A/sccm (Ar)
2-5 A/sccm (Xe) - Length: 6.8 inches
Ground-based HCPEE Systems
Utilizing a state of the art, highly integrated design, the Hollow Cathode Plasma Electron Emitter (HCPEE) systems minimize unit cost, installation, and replacement time. Response to user control inputs is rapid, with excellent plasma electron emission stability during operation. Each HCPEE system has demonstrated long steady-state and duty cycle lifetimes in numerous applications.
HCPEE systems are available for the 250, 375, 500 and 625 hollow cathodes. Systems are delivered as ready-to-operate packages. Mounting and interconnects are simple. Flexible orientation and small size permit installation in volume-confined vacuum facilities. The HCPEE systems require a clean gas feed system and 90-250 VAC at 50/60 Hz for operation.
HCPEE System

- Hollow Cathode Plasma Electron Emitter (HCPEE) 250, 375, 500, or 625
- Start and Standby Power System (SSPS) for selected HCPEE models
- Vacuum flange with power and gas feed-throughs
- In-vacuum and out-of-vacuum wiring harnesses
- Integrated gas flow electrical isolator
- Remote HCPEE mount
Space-based Hollow Cathodes (SFHC)
EPL manufactures three Space Flight Hollow Cathode (SFHC) models, with steady state plasma electron emission current ratings up to 25 A. Operating gasses include Xe, Kr, and Ar. These cathodes have a robust structural design to survive launch vibration and shock. Multiple EPL space-flight hollow cathodes have flown, and are flying, in space.
Complete qualification services are offered by EPL for its SFHC products. These services include, but are not limited to, life testing, specific user launch vehicle vibration and shock testing, and thermal vacuum hot and cold soak testing.

SFHC 175F, standard T-mount
- Plasma electron flux: 0-3 A
- Xe gas electron efficiency (typical into plasma load): 50 A/mg/s
- Status: flight qualified and flight proven

SFHC 250F, unmounted
- Plasma electron flux: 0-10 A
- Xe gas electron efficiency (typical into plasma load): 50 A/mg/s
- Status: flight qualified and flight proven

SFHC500F operating at 40 A with xenon as part of a 3,000 hour endurance test.

SFHC 500F, mounted
- Plasma electron flux: 0-25 A
- Xe gas electron efficiency (typical into plasma load): 50 A/mg/s
- Status: flight qualified