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The home office is located 60 miles east of New York City near the Brookhaven National Laboratory and Stony Brook University.

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BTG is a member of The United States Industry Coalition, Inc. (USIC), a non-profit association of U.S. companies and universities dedicated to the nonproliferation of weapons of mass destruction through commercialization of technologies for peaceful purposes.

Advanced Accelerator Research and Development:

Surface Plasma Negative Ion Sources
The Surface Plasma Source (SPS) is a particular type of negative ion source that uses cesium or other materials to enhance negative ion production. The BTG surface plasma heavy negative ion source (SPHNIS) is based on negative ion formation by secondary emission of negative ions enhanced by cesium catalyst admixture to the discharge. The main features of the negative ion sources developed by BTG are:

High current,
High electrical efficiency
High gas efficiency and
Compact size
Long lifetime

The main applications of these ion sources are as injectors into tandem accelerators, cyclotrons, linacs and neutral beam devices.

The BTG surface plasma negative ion sources are designed for high brightness and high gas and power efficiency. Several versions have been designed and tested.

SPS with Spherical Focusing Emitter
The high brightness DC Surface Plasma Heavy Negative Ion Source (DC-SPHNIS) employs a hollow cathode discharge in a crossed ExB field for efficient plasma generation. The heavy negative ion beam is formed by the interaction of the plasma with the surface of a spherical focusing emitter. The emitter material is made of different materials depending on the desired ion species. Results for copper, lanthanum hexaboride and gold with cesium catalysis are presented in the Table above.

up to 900 µA of boron negative ion beam was measured in a Faraday cup located 25 cm from the ion source with an emission aperture of 3 mm. The emittance of the B

boron beam with current 500 µA was measured as 13

mm mrad (MeV)

.

A smaller version of DC HNISPS with emitter diameter of 9 mm was developed, designed and tested for production of a heavy negative ion beam with a higher brightness. With a copper emitter and emission aperture of 2 mm diameter negative ion beam with current 600 µA was produced.

Pulsed Version
A pulsed version of SPHNIS with emitter diameter of 9 mm was developed, designed and tested for production of heavy negative ion beam with a higher brightness. A fast pulsed valve is used to minimize gas consumption. The valve can be operated at rates up to 1 kHz. With a gold emitter and emission aperture of 2 mm diameter in the Faraday cup, a pulsed beam current up to 1.5 µA for 1.5 ms is obtained with repetition rate up to 10 Hz.

Negative Ion Sources
The BTG Surface Plasma Heavy Negative Ion Source is very compact, high efficiency and of high brightness. It is designed for use on tandem accelerators as well as other applications that demand high current and high brightness beams.

In a DOE sponsored SBIR, BTG successfully completed development of a high current, heavy negative ion source for research and high energy ion implantation. The ion source is designed to fit onto most ion implanters. It will provide a wide range of heavy negative ions.

A photograph of the completed ion source is shown below.

Other Accelerator Technologies:

BTG News

June 22, 2006

Brookhaven Technology Group, Inc., was awarded a new Phase I SBIR grant to develop an advanced surface plasma source for reliable long time production of H¯/D¯ beams with high brightness and high pulsed current and average intensity up to ~20mA. The principal goal of this project is to develop a high performance, long lifetime surface plasma H¯ source by using a unique new highly efficient helicon discharge plasma generator. The plasma flux formed by this helicon discharge will be used for surface plasma generation of H¯.

In Phase I, simulations of plasma generation, ion/atom conversion, and H¯/D¯ surface-plasma generation will be carried out to prove the feasibility of this new approach. The discharge system will be studied, beam extraction and formation including electron suppression will be designed, and computer simulated.

This is the third Phase I SBIR awarded to BTG for development of negative ion source technology. In previous years the company received Phase I and Phase II funding to design, build, and test a high brightness, long lived source of heavy negative ions (HNIS). This source is now available for commercialization. More information about the HNIS is available on this website.