Re: Unsafe High School Science Project

[Lew Helgeson <lewhelgeson@helge.com>]

To all RadSafers,

Something happened to the last part of my previous posting - it didn’t get
transmitted. Since it relates directly to the young girl who did the same
experiment, I want to re-transmit the first part as well at the last part. It
will also give me a chance to correct a few typos.

This reminds me very much of my own experience when I took "Physics" in my
Junior year at Denfeld High School, Duluth, Minnesota, in 1940. I used the
filament from a Type 80 radio tube (a rectifier) and one of the plates. These
were sealed into a 0.75-inch diameter glass tube with a wall thickness of about
0.0625-inch (one-sixteenth, as I remember). Its general appearance was similar
to the "Crooke's Tube" that Miss Seipel (my Physics teacher) had for class
demonstrations. I had a 0,25-inch glass tube fused into the side of the larger
diameter tube and this was hooked to a vacuum pump. My power source was similar
to this young girl's: a Ford Model T spark coil connected to two 6-volt car
batteries in series to give 12-volts (and in 1940 there were still quite a few
of these older cars around). My wiring was also exposed at the terminal ends.
The glass "Crooke's Tube" was held in place by standard laboratory clamps and
stands. To determine if I could actually produce x-rays, I loaded a piece of
4x5 photographic film from my Dad's Speed Graphic camera (I think the ASA
rating was about 60). This film was placed on the laboratory bench about
8-inches below the tube and was left there with a key on top of it to replicate
Roentgen's classical experiment. The exposure time was from Friday afternoon
until Monday morning.

I processed the film Monday evening and ws excited to see the faint shadow of
the key. I wrote up the experiment, received an "A," and moved on to the next
project.

When I enlisted in the Army (after 2-years of college) the Army Interviewer
asked about my hobbies. I told him about my ham radio interests, hoping to get
into the Signal Corps. I also told him about the x-ray tube experiment. His
reaction: "You are a natural for the Army Medics as an X-Ray Technician," and
that is what I became.

During my almost three years of work at the 192nd General Hospital in England I
was asked by the Radiologist to use the Victoreen Condenser R-Meter to measure
the dose rate from the old Picker Portable X-ray machine. He used this
equipment to irradiate Plantar Warts on the feet of solders (I referred to this
in a previous posting months ago.)

After I was discharged from the Army in April 1946 I finished my schooling in
Chemical Engineering at the University of Washington. In February 1948 the
interviewers from General Electric, then operating the Hanford Project,
interviewed many of the graduating Chem. Engineers. The interviewer asked about
my army experiences. When I told him about the plantar wart project, he said
"You are a natural for our Health Instruments department." Thus, I was one of
the 8 people hired, 7 of them at a pay rate of $57.00 per week to do chemical
engineering at Hanford, but my pay rate was $59.60 per week, because of my
previous experience of measuring the dose rate from the x-ray machine. 
After eight and a half years at Hanford I was transferred to the General
Electric Atomic Power Department in Pleasanton, California, where I had the
responsibility for the technical basis of the Health Physics program at the
Vallecitos Atomic Laboratory. When Bill Roesch and Earl Palmer presented their
paper on the “Shadow Shield Whole Body Counter” at the Las Vegas Annual Health
Physics Meeting (later published in Health Physics, Vol 11. pp1213-1219, 1965),
I knew that this was the answer to many puzzling questions about incorporation
of radioactive materials into the body. I talked my boss into letting me build
one at Vallecitos. It proved to be a real winner, however, General Electric was
not interested in “taking it on the road” to provide a whole body counting
service to the nuclear industry. As a result, in February 1966 I was either
unemployed or an “entrepreneur” and formed Helgeson Nuclear Services (later
re-named to Helgeson Scientific Services).

Now, more than 34 years after forming my company and more than 60 years after
building my x-ray tube, I can look back to what started a lot of my history:
the truly dedicated interest Miss Seipel had in stimulating her students about
the wonders of science. Whenm in 1966, I made my first business trip to drum up
the use of our mobile whole body counting service, I had the priviledge of
visiting Miss Seipel in Duluth. She had long been retired from teaching, but
when I told her my name, she remembered me as “the x-ray boy” and wondered what
had happened to me. She was “thrilled” to know how much of her influence had
caused me to be in my current occupation. As a side-note, I think that many of
us could thank our teachers in their later years for what they have done to
help us get to where we are.

But back on the subject of the girl who did the same experiment as I did so
many years ago. Yes, she probably should have asked her counselor to comment on
the safety of her experimental equipment. But I would also hope that the thrill
of seeing the geiger counter react as it did (whether or not it was truly
responding to x-rays or static from the spark coil) would spur her to continue
her investigative bent into the fields of science.

Now, what am I doing at the present time? At almost 77 years young (October
2nd) I am still working “half-days (no more that 12 hours). I had planned to
retire at age 65 when my wife quit her organist-choir director’s job after more
that 40 years, but I didn’t. In fact, I didn’t even re-apply for CHP Emeritus
because I thought (with my wife’s prodding) that in a short time I would be
fully retired. I still have the inquisitive mind that I suspect our young girl
has and I hope that her spirits haven’t been dampened by the negative comments
regarding the safety of her experiment. To Mr. William Nabor, the person who
started this thread, if you can talk with this young girl, please pass on my
thoughts and encourage her to continue her pursuits.


Lew Helgeson
lewhelgeson@helge.com



At 11:51 AM 4/13/2000 -0500, you wrote:
>Dear RADSAFER's:
>
>     Yesterday I and a fellow member of the Southern California
>Chapter of The Health Physics Society helped judge the Orange
>County, California, Science Fair, an exposition in which students
>aged 11 to 17 display their science projects.  The Chapter offers
>an award to the best project involving radiation.  In the past some
>of the projects have been truly amazing and ingenious.  Others have
>been less so.  This year we ran into one that was frightening,
>presenting a clear and imminent safety hazard to the student,
>possibly lethal.  We fully intend to communicate with the student's
>teacher and the fair officials expressing our concern.  However we
>wish neither to discourage the student or her teacher from further
>participation in science nor to bring up the specter of big, bad
>radiation.  Therefore, I would appreciate any advice any RADSAFEer
>would care to give on how best to proceed.  Please address your
>comments to WGNABOR@UCI.EDU rather that to the list in general, as
>I don't suppose many RADSAFEers would be interested in such a rare
>occurrence.
>
>   The project was a home-made X-ray machine constructed by a 15
>year-old high school student in the following manner:  The power
>supply was a 12 volt DC 10 amp commercial automobile battery
>charger, the output from which was connected to a vibrator.  No,
>not that kind of vibrator.  This one was a voltage booster.  The
>negative output lead from the vibrator was connected to the base of
>an ordinary incandescent lightbulb.  The positive lead was
>connected to the tip if the glass globe under several layers of
>aluminum foil, uncalibrated eyeball estimate 1mm thick.  The
>student _claimed_ that she used a "geiger counter" to measure the
>output from this device and got a 300 to 1000 mR/hr dose rate.
>
>   We immediately started asking questions about this geiger
>counter to determine how likely was it that this reading was
>correct.  Unfortunately, English was not her native language.  We
>could not determine if the responses we got from the student
>indicated her total unfamiliarity with the physics involved or of
>English.  She could not describe the counter.  The photograph she
>had of the device was out of focus and overexposed so we could not
>tell what kind of device it was except that we had never seen a
>geiger counter of this sort before.  It looked somewhat like a
>Ludlum AC powered area monitor, but was certainly no Ludlum
>product.  Neither was it an old civil defense survey meter that the
>U.S. government passed out ad libitum after the end of the cold
>war.  Some of these could read in the R/hr range.
>
>   We attempted to get some indication of the output of the
>vibrator, which was housed in a wooden box with no external
>markings of any sort.  She appeared not to understand the term
>amperage at all and continuously confused voltage with wavelength.
>We could, therefore, not determine either the output voltage or the
>amperage of the vibrator and so remain ignorant of these two
>critical parameters.
>
>   Our safety concerns are three:  First, the electrical safety, of
>which there was none.  With the exception of the power cord to the
>commercial battery charger every connection was bare.  Alligator
>clips, aluminum foil, bare wires, even the connections to the
>lightbulb and the 120 volt AC mains, all were fully exposed.  This
>represents a potentially lethal and fully unacceptable situation
>which we will communicate to the teacher.
>
>   The second was a minor fire hazard as the lightbulb was tightly
>taped to an unpainted pine two-by-four.
>
>   It is the radiation hazard with which I am asking help from
>RADSAFE.  I am requesting your opinions on the following:
>   1)  Remembering that the target is thin glass and about 1mm of
>Al, and that the positive lead is connected to the outside of the
>glass globe, how likely do you think it that this device could
>produce X-rays or beta rays?
>   2)  If it can produce ionizing radiation, how likely is it that
>it can produce 300 to 1000 mR/hr?  We were not about to suggest
>that she turn it on in the exhibition hall so we could take
>measurements!
>   3)  How best can we word our communication so as to prevent such
>a project in the future without discouraging others from interest
>in radiation?
>
>   Finally, no, we did not give this project an award.
>
>   Thank you for your help.
>**********************************************************************
>William G. Nabor
>University of California, Irvine
>EH&S Office
>Irvine, CA,  92697-2725
>WGNABOR@UCI.EDU
>mailto:wgnabor@uci.edu
>**********************************************************************
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