Documents / Official release

AAWSAP DIRD, High-Frequency Gravitational Wave Communications, April 2010

U.S. Department of War · 2010-04-06 · 57 pages · text from the file's own layer

This Defense Intelligence Reference Document, DIA-08-1004-005, is dated 6 April 2010. The Defense Intelligence Agency's Defense Warning Office prepared it under the Advanced Aerospace Weapon System Applications program. It reviews proposed laboratory generators and detectors for high-frequency gravitational waves. It favors a piezoelectric approach for proof-of-concept tests, IR-excited molecules for an operational transmitter and the Li-Baker detector as the receiver. It estimates about 1.9 million bits per second over 7,000 km through the Earth and discusses timing standards and interplanetary navigation uses.

From the source: Release of 2026-09-18 Incident: 4/6/10, Las Vegas, Nevada. Released with redactions. This document is a Defense Intelligence Reference Document (DIRD), a technical reference format used by the Defense Intelligence Agency (DIA) to capture baseline knowledge on a specific topic for later analytic use. DIRDs are best understood as reference and synthesis products rather than as original research. It is one of 38 DIRDs produced under the Advanced Aerospace Weapon System Applications Program (AAWSAP) between 2009 and 2011. Because AAWSAP’s scope permitted a broad range of supporting topics, not every DIRD in the series directly concerns aerospace systems or future threat assessment. The following summary reflects the DIRD’s scope and framing at the time of writing and should not be read as implying current validation of the concepts discussed. This DIRD examines whether high-frequency gravitational waves could serve as a communications medium while avoiding the attenuation that limits radio-frequency systems. The report surveys proposed transmitter and detector concepts, argues that gravitational-wave communications could support secure point-to-point links, timing standards, and interplanetary navigation, and gives particular attention to laboratory generator concepts and the Li-Baker detector as possible building blocks for such a system. The document makes clear, however, that the entire concept depends on capabilities that had not been demonstrated in practice, including laboratory-scale generation and reliable detection of usable high-frequency gravitational-wave signals. It is an exploratory systems-oriented review built around a future communications concept.

UNCLASSIFIED/ /iiOR OiiiilCI OL lallili QPIL¥
one-microsecond-long pulses one second apart. The required average power for each
FBAR band will now be 10 W. As a practical nanotechnology limit, the slice width can be
reduced by two orders of magnitude to 10 nm. This would also require that the row
displacements would be 110 pm (we are now into atomic if not sub-atomic dimensional
changes). The overall length could be reduced to about 2 cm or the ampl itude of the
HFGWs could be increased to A= 4.9x10-26 . In this latter case the average energizing
microwave power applied to each band wou ld need to be increased to 1 kW. A preferred
compromise in this apparent nano-technology limit might be to reduce the HFGWs
generator's length to about 20 cm and increase the HFGW amplitude A to 4x 10-27 m/m.
The complementary approach to optimizing a practical HFGW generator is to increase
the force produced by each element without increasing the required power (that is,
increasing element efficiency). This was initially done using the modern light-weight
piezoelectric FBARs rather than the heavy 10-gram crystals considered by Dehnen and
Romero-Borja that were of 1981 vintage. Special designs of FBAR-like elements for
optimum force-generation efficiency will improve the HFGW generator performance
beyond that for the usual cell-phone FBAR designs. Another approach to element design
is to utilize nano-size lasers whose targets are the force-generating elements (Li and Li,
2006). Utilization of myriads of nano-size lasers would generate high-frequency HFGW
pulses as noted in U. S. Patent Number 6,784,591. Thus there are a number of
opportunities to enhance HFGW generation performance, utilizing special element
designs, either by reducing the generator size or increasing the generated HFGW
ampl itude or both.
2.1.4 Infrared-Excited Molecules Approach
The very theoretical IR-generated HFGWs suggested by Woods and Baker (2009) have
significant promise. If one has a standing wave in a waveguide ring and excites it
properly, then one will have a GW source at its center, as shown in Figure 3. The GW
flux produced at its center is proportional to the n submicroscopic particle pairs (in this
case pentane molecule pairs) in each ring. There is no n2 bui ldup, but there is an n
buildup. If one has a stack of N plates of rings, which are excited in sequence at light
speed as a generated, growing as a GW passes by, then one has an nN2 buildup in GW
flux.
UNCLASSIFIED/ /FOR OiiiilCl.t.k HSI!! eflti
7

Not linked to a story yet.

About this file

Official release, from the pursue collection. The PDF is mirrored here; the original link is above. 57 pages are in the text index: search them above, or from the library's search.