© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

4.7.4 Particulate and High-Energy Radiation

High energy photons including X-rays (l ~ 2 nm, ~10⁵ zJ or 0.0001 picojoule) and gamma rays (l ~ 0.002 nm, ~0.1 picojoule), and ejecta from the decay of radioactive nuclei such as a-particles (helium nuclei, ~1 picojoule) and b-particles (free electrons, 0.01-0.1 picojoule) may be extremely destructive to nanomechanical systems (Chapter 13) and are difficult to reliably measure quantitatively. For example, a charged particle with 0.01 pJ of kinetic energy (K.E.) traversing a decelerative electrostatic field of 10⁹ volts/m requires K.E./qE ~ 60 microns to slow to a halt. However, particle-induced visual sensations have been observed by dark-adapted astronauts in space,⁵⁰⁴ and Ruderfer⁷⁰² has suggested that even solar neutrinos may be detectable by the human brain (though most physicists would find this implausible). The nucleoelectric transducer described in Section 6.3.7.1 could be adapted to serve as a directional a particle sensor.

Last updated on 17 February 2003