seeing light flashes -Reply

[FRAMEP@ORAU.GOV]

>I remember hearing accounts that astronauts on Apollo missions and
>folks who inadvertantly stuck their heads into accelerator beams
>have seen light flashes, but I cannot find a references to support
>this. Anybody got any references?
>Kim.

"Observations of Visual Sensations Produced by Cerenkov Radiation
from High Energy Electrons" Steidley et al. Int. J. Rad. Oncology
Biol. Phys. V17 pp685-690. 1989. It contains numerous other
references. You could also call Steidley, he's a fine fellow and
loves to talk about the phenomenon. He's in the HPS membership
handbook.

They are called particle induced visual sensations (PIVS) which is a
class of radiation phosphene. As the title of the paper indicates,
the mechanism is via cherenkov radiation. Interestingly, x-rays can
act directly on the retina and appear as a blue-grey glow.

In his first paper on x-rays, Rontgen reported that he was unable to
see the things directly, but a year later, in his third paper, he
reported that with a powerful enough tube and with your head right up
against it, you could "see" them. Pierre Curie got some degree of
pleasure by seeing radiatition from a radium source placed against
the eyes/forehead.

Not only can you see radiation, it is also possible to feel it in
some situations. Rather than describe it here, I'll leave it to your
imagination (see HP Journal Vol 36 pp437-441, 1979 "Another Co-60 Hot
Cell Accident").

Best wishes

Paul Frame
Professional Training Programs
Oak Ridge Institute for Science and Education
framep@orau.gov