Re: secondary x-rays from ultra-sound:proved to exist

[Eugene Mah <eugenem@ix.netcom.com>]

it's actually not quite so far fetched as it sounds.
there have been reports of low-energy x-rays detected
along with a phenomenon called sonoluminesence seen
with ultrasound.  The ultrasound creates microscopic
bubbles which, when they collapse, emit flashes of light.

searching acoutic related journals should reveal oodles of
additional info on the subject

here's a description of a student experiment in sonoluminesence
http://www.uah.edu/research/resrev96/Micro/students.html

Eugene
---------------------------------------------------------------------
Eugene Mah, M.Sc.                     eugenem@ix.netcom.com
Medical Physicist                     maheug@musc.edu
Department of Radiology               "For I am a Bear of Very Little
Medical University of South Carolina   Brain, and long words Bother
Charleston, South Carolina             me."   Winnie the Pooh
http://www.netcom.com/~eugenem/
PGP KeyID = 0x1F9779FD, 0x319393F4
PGP keys available on request         ICQ 3113529                 O-
---------------------------------------------------------------------

At 05:03 AM 14-05-1999 -0500, you wrote:
>This seems energetically impossible to me. The only "x-rays" possible
>are characteristic x-rays.  In order for them to be classified as
>"ionizing" radiation they must be 13.6 eV or greater.  The only
>electrons available to be effected by mechanical collisions as with
>ultrasound or thermal processes are the "valence" or outer electrons. 
>It seems unlikely that these electrons (in biological systems) will
>have binding energies of 13.6 eV.  To associate ultrasound and x-rays
>simply because of their associated "wave" properties is to demonstrate
>a fundamental ignorance of both processes. 
>
>--- Rachid Zitouni <azittouni@yahoo.com> wrote:
>> 
>> 
>> --- LAM HOI CHING <lamhc@hkusua.hku.hk> wrote:
>> 
>> > Ultansonic wave is only a kind of mechanical
>> > effect,it is a kind of
>> > macroscopic phenomenon in the material, it affects
>> > only the mechanical
>> > vibration of atom, but  not to the atomic
>> structure
>> > change like the atomic
>> > orbital,whereas x-rays are due to internal
>> > transition of atom or molecules,
>> > in fact from electrons of the atom, these two
>> > effects are not in the same
>> > category.
>> > 	But you can discuss ionizing damage from x-ray
>> > (doses)
>> > or you can still discuss the harmful effect of
>> > ultrasound. The two types of
>> > interactions (by ultra-sound and x-ray) are
>> totally
>> > different.
>> > 
>> > 
>> 
>> Few years ago, I would have agreed with you. Yes,
>> ultrasound acts on
>> the bulk of the matter, at the macroscopic level and
>> X-rays at the
>> electronic level.
>> Ultrasonic waves are not supposed to ionize matter.
>> 
>> BUT:
>> Very low Enegy X-rays have been detected following
>> diagnostic
>> ultrasound. I lost track of the paper which was
>> published on this
>> subject.This phenomenon has been proved to exist. I
>> haven't done the
>> experiment myself, but I suppose the excitation of
>> matter by ultrasound
>> at the molecular level may, under certain
>> circumstances (which are to
>> be determined), give rise to very low energy X-ray 
>> 
>> By the way, I haven't referred to any biological
>> effect related to
>> these low-energy X-rays. In fact, the dose in this
>> case is meaningless.
>> 
>> Thanks for the reply and keep digging if the subject
>> is of interest to
>> you.
>> 
>> Abderrachid ZITOUNI, health Physicist
>> 
>> azittouni@yahoo.com

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html