Unexpected sources of X-rays
Stories from Physics
for 11-14
14-16
- Though the emission of X-rays from lightning had been predicted several decades ago, it is only in recent years that the high-energy radiation has been detected. However, the mechanism by which lightning produces X-rays is currently poorly understood.
- Peeling Sellotape generates X-rays and a team at the University of California have produced enough X-rays to take an image of one scientist’s fingers by uncoiling tape in a vacuum. The phenomenon is a form of triboluminescence, the release of energy from the breaking of chemical bonds when mechanical energy is applied to a material.
- Triboluminescence was first reported in 1605 when Francis Bacon observed that lumps of sugar released light when scraped. Many common sweets will display the effect and a paper reports the spectra of radiation given off by an American Wint-O-Green Lifesaver TM. Diamonds are both triboluminescent and thermoluminescent: a thirteenth century bishop, Albertus Magnus, noted that the precious stones emitted light when placed in warm water and Robert Boyle observed that a diamond fluoresced when struck with a bodkin.
References
J. Howard, M. A. Uman, J. R. Dwyer, D. Hill, C. Biagi, Z. Saleh, … & H. K. Rassoul, Co‐location of lightning leader x‐ray and electric field change sources. Geophysical Research Letters, vol. 35, no. 13, 2008, 13817, pp. 1-5.
Scientists Close In On Source Of X-rays In Lightning, 16th July, 2008, Science Daily Website, https://www.sciencedaily.com/releases/2008/07/080715152322.htm
K. Sanderson, Sticky tape generates X-rays, Nature Website, 22nd October 2008, http://www.nature.com/news/2008/012345/full/news.2008.1185.html
J. I. Zink, Squeezing light out of crystals: triboluminescence. Naturwissenschaften, vol. 68, no. 10, 1981, pp. 507-512, p. 501.
L. M. Sweeting, Light your candy. ChemMatters, vol. 8, 1990, pp. 10-12.
J. R. Hird, A. Chakravarty, & A. J. Walton, Triboluminescence from diamond. Journal of Physics D: Applied Physics, vol. 40, no. 5, 2007, pp. 1464-1472, p. 1465.
