Form 9.B Project Summary



Proposal Number:


Project Title:

High Efficiency Neutralizer for Electric


Technical Abstract (Limit 200 words)

The Physitron Team proposes to apply Chemical

Vapor Deposited (CVD) Diamond micro-tip field

emitter arrays (FEAs) to electric propulsion. These

arrays consist of micro-fabricated pyramids of CVD

diamond which have been demonstrated to have

extremely low thresholds for electron emission.

Current small electric propulsion systems waste as

much as 30% of the available energy in generating

electrons for ionization and neutralization.

Application of this technology will reduce the size,

weight, and power requirements of these

subsystems by utilizing micro electro-mechanical

systems (MEMS) technology and significantly

increasing the efficiency of electron production. The

long term objectives of this project are to deploy

Diamond MEMS FEAs in neutralizers for electric

propulsion and as plasma contactors for spacecraft.

During Phase 1, we will demonstrate adequate field

emission properties of the FEAs, design a CVD

diamond grid structure, and deliver FEAs to NASA

for inspection. During Phase 2, we will fabricate and

deliver a pre-prototype neutralizer with diamond

MEMS FEAs and a diamond grid which will provide

60 milli-amps at 2 volts bias with 95% efficiency

from a 1 square millimeter device.

Potential Commercial Applications (Limit 200 words)

Micro-fabricated CVD diamond FEAs have been

demonstrated to have the absolute lowest threshold

for electron emission and the lowest erosion rate

for ion bombardment. Therefore, numerous

commercial applications exist including spacecraft

propulsion systems, high power/frequency vacuum

tubes, and flat panel displays. The low voltage

emission and high temperature capability of

diamond is an excellent match to high power

microwave devices. The low threshold for and

uniformity of emission provided by the FEA

approach will allow lower power flat panel displays

for portable applications such as laptop computers.

Name and Address of Principal Investigator (Name,

Organization Name, Mail Address, City/State/Zip)

Theron G. "Bo" Henderson

Physitron, Inc.

3304A Westmill Dr.

Huntsville , AL 35805

Name and Address of Offeror (Firm Name, Mail Address,


John M. McSwain

Physitron, Inc.

3304A Westmill Dr.

Huntsville , AL 35805