[ RadSafe ] X-ray production near xenon arc lamps? (UNCLASSIFIED)

[Brennan, Mike (DOH)]

Hi, Jerry.

While this isn't my field, it seems to me that x-rays would be produced
when the electrons from the cathode slam into the anode.  The high
voltage at ignition are in the range of what is used with an x-ray tube,
so I don't have much trouble imagining that there would be x-ray
production (though I have no idea how much).  I suspect that the
sustaining voltage isn't high enough to generate x-rays, especially as a
fair portion of the energy is being used to excite the gas molecules.  

>From a risk point of view, I suspect that x-rays are not in the top five
of hazards that someone working with xenon arc lamps should keep in
mind.  The first, I suspect, is that the light is so bright that
permanent eye damage is only an inattentive moment away.  50kV with
non-trivial amps can alter your lifestyle very quickly.  A quartz tube
with 300 atm would explode like a glass grenade if handled too roughly.
The lamp is probably hot enough to char flesh.  All of these hazards are
probably dealt with in the design of most of the machines using the arc
lamps, but I am always amazed at the ways people find to overcome safety
systems.

-----Original Message-----
From: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] On
Behalf Of Falo, Gerald A Dr CIV USA MEDCOM CHPPM
Sent: Wednesday, May 20, 2009 9:01 AM
To: radsafe at radlab.nl
Subject: [ RadSafe ] X-ray production near xenon arc lamps?
(UNCLASSIFIED)

Classification:  UNCLASSIFIED
Caveats: NONE

Greetings all,

I've been asked a question about x-ray production near xenon arc lamps
used in search lights.  All I've been able to discover is that the
greatest potential for x-ray production would be during ignition.
Ignition requires voltages in the 20kV to 50kV range; sustaining
voltages runs in the 10V to 100V range.  Typical lamps run at pressures
greater than 25 atm (2.5 GPa) (I've seen references to pressures as high
as 300 atm (30 GPa)).

My suspicion that the high voltage power supply might be a source of a
very short bust of ~10kV x-rays, but I have found no hard information.

Does anyone know of any studies been published regarding x-ray
production near xenon arc lamps?

Thank you,
Jerry

________________________________

The statements and opinions expressed herein are my responsibility; no
one else (certainly not my employer) is responsible, but I still reserve
the right to make mistakes.
 
Don't panic! - Douglas Adams in "The Hitchhiker's Guide to the Galaxy"
 
Gerald A. Falo, Ph.D., CHP
U.S. Army Center for Health Promotion and Preventive Medicine - Health
Physics Program jerry.falo at us.army.mil
410-436-4852
DSN: 584-4852

Classification:  UNCLASSIFIED
Caveats: NONE

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