AS&E Announces $3.5 Million Award from Accuray Oncology.

Business/Technology Editors

BILLERICA, Mass.--(BUSINESS WIRE)--Sept. 22, 2000

American Science and Engineering, Inc. (AMEX:ASE) announced today a follow-on order valued at $3.5 million to AS&E(R)'s High Energy Systems (HES) division for multiple linear accelerator systems. The accelerators will be manufactured for Accuray Oncology to be used in stereotactic radiosurgery. This procedure uses radiation to shrink or kill tumors, allowing doctors to avoid invasive surgery or to treat non-operable growths.

Ralph Sheridan, CEO and President, stated, "An important element of AS&E's technology development is our High Energy Systems Division (HES) in Santa Clara, California. We are proud to be a partner with Accuray Oncology in pioneering a robotic system for stereostatic treatment of brain cancers. Our contribution is the design of a highly efficient, compact linear accelerator that provides a precision radiation source. HES's technology advances in medical and non-destructive test markets are also paying significant dividends in the development of future cargo security inspection systems, as well as linear accelerators for curing of high performance polymers and eliminating bacterial contamination in foods."

AS&E develops and manufactures sophisticated X-ray inspection products for critical detection and security applications. These systems are solving an expanding range of inspection problems, including detecting car and truck bombs, combating weapons smuggling, and imaging cargo to expose trade fraud and illegal immigration. AS&E has delivered more X-ray cargo inspection systems than anyone in the industry, and continues to be the leader in X-ray detection technology and applications. AS&E's patented Z(R) Backscatter technology detects plastic explosives, illegal drugs, and other contraband, even when artfully concealed in complex backgrounds by terrorists and smugglers. AS&E's High Energy Systems Division manufactures linear accelerators for a variety of applications including medical, scientific, security, electron beam curing and non-destructional testing. For more information on AS&E products and technologies, please visit the Company's web site at http://www.as-e.com.

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The foregoing press release contains statements concerning the Company's financial performance and business operations which may be considered "forward-looking" under applicable securities laws. The Company wishes to caution readers of this press release that actual results might differ materially from those projected in any forward-looking statements. Factors which might cause actual results to differ materially from those projected in the forward-looking statement contained herein include the following: significant reductions or delays in procurements of the Company's systems by the United States and other governments; disruption in the supply of any sole-source component incorporated into the Company's products (of which there are several); litigation seeking to restrict the use of intellectual property used by the Company; potential product liability claims against the Company; global political trends and events which affect public perception of the threat presented by drugs, explosives and other contraband; global economic developments and the ability of governments and private organizations to fund purchases of the Company's products to address such threats; and the potential insufficiency of Company resources, including human resources, capital, plant and equipment and management systems, to accommodate any future growth. These and certain other factors which might cause actual results to differ materially from those projected are more fully set forth under the caption "Risk Factors" in the Company's Registration Statement on Form S-3 (SEC File No. 333-9151).