Armed Services Committees Refuse to Authorize SIER Weapon Research

Share This

Publication date: 
4 June 2004

Both the House and Senate Armed Services Committees have recommended no research funding for a Stimulated Isomer Energy Release (SIER) that could, some researchers predict, lead to the development of a new weapon. The Bush Administration requested $4.0 million in FY 2005 funding for SIER in the DARPA budget.

This program was described in the FY 2005 RDT&E DARPA budget estimates document as follows:

"Nuclear isomers, such as hafnium 178m2, store in the nucleus 10,000 times as much energy per gram as TNT. The goal of the Stimulated Isomer Energy Release program is to develop a technique to control the release of this energy. It will develop a way to make these isomers in gram-size quantities. The program will demonstrate that as much energy can be released as is used to initiate the reaction (a breakeven experiment)." The Program Plans were as follows: 1.) "Determine if the hafnium isomer can be triggered with photons in the x-ray range that will release more than 50 times the energy input of the trigger." 2.) Identify a hafnium isomer production process that is affordable and cost effective." 3.) "Develop a physics approach to a chain reaction for the hafnium isomer."

Readers desiring more information on this program should see an article in the May 2004 issue of PHYSICS TODAY by Bertram Schwarzschild, "Conflicting Results on a Long-Lived Nuclear Isomer of Hafnium Have Wider Implications," at

The House Armed Services Committee and Senate Armed Services Committee explained in their reports accompanying the FY 2005 defense authorization bills the reasons why they recommended against DARPA funding of this program. This report language is as follows:


"Stimulated isomer energy release

"The budget request contained $339.2 million in PE 62702E for tactical technology applied research, including $4.0 million for stimulated isomer energy release.

"The committee is aware that the Defense Advanced Research Project Agency (DARPA) is funding research to investigate the feasibility of stimulating the release of energy stored in nuclear isomers. The committee understands that the DARPA-sponsored research is investigating two of the most difficult technical challenges in this program and that the research is being conducted in the national laboratories, the Department of Energy, the military service laboratories, and other facilities. Given the significant policy issues associated with any eventual use of an isomer weapon and given the inability of distinguished scientists to replicate the reported successful triggering experiment of 1998, the committee believes that the Department of Defense should not be engaged in this research. The proper agency to investigate the feasibility of this technology is the National Nuclear Security Administration and its national laboratory complex. The committee questions the utility of this research in any circumstances and is particularly skeptical of research into nuclear isomer production before triggering is shown to be possible.

"Accordingly, the committee directs the Secretary of Defense to terminate this program, and recommends no funding for the stimulated isomer energy release in PE 62702E, a reduction of $4.0 million."


"Tactical technologies

"The budget request included $339.2 million in PE 62702E for applied research on tactical systems. The committee recommends a total reduction of $25.0 million from this account. The committee recommends a reduction of $4.0 million from the Stimulated Isomer Energy Release program. The committee agrees with the majority of expert technical opinions that this effort, though carrying a large potential payoff, should be a smaller fundamental research effort at this time."

Explore FYI topics: