Re: Airport and Building X-Ray machines and Digital Cameras
- From: Clark Martin <cmnews@xxxxxxxxx>
- Date: Wed, 05 Oct 2005 01:45:16 GMT
In article <1126823947.947139.171460@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Alan Meyer" <ameyer2@xxxxxxxxx> wrote:
> Roger N. Clark (change username to rnclark) wrote:
>
> > ... But the original
> > hospital X-ray machine should not have had x-rays leaking out,
> > or did you put it in the machine?
>
> The X-ray machine in this case was not a diagnostic machine
> but a treatment machine. It puts out very much higher energy
> X-rays than are used for diagnostics in order to damage the
> nuclei of cancer cells in such a way that they are unable
> to divide and reproduce.
>
> The patient lies on a table and the machine rotates around
> and underneath him, shooting rays from different angles and
> with different focal lengths and apertures in order to
> deliver the maximum dosage to the tumor and the minimum
> dosage to healthy tissue around it. The idea is that, by
> focusing on the tumor and moving the emitter, the entry and
> exit beams pass through different parts of the body giving
> each a relatively low dose, while the tumor at the focal
> point gets the full dose no matter what angle the emitter
> is at.
Not different focal lengths, the only way to focus X-Rays requires
something like a black hole. The beam shape and intensity and possibly
energy can be changed as it rotates (Arc Therapy).
>
> Unfortunately, my briefcase with the camera inside was off
> to one side of the table and must have gotten zapped when
> the X-ray emitter was aiming from the other side of the table.
It's possible it just got some scatter too. It's also possible it was
too close to the modulator. This is what turns the 208 (or 380) V 3
phase power into the pulses the Magnetron or Klystron needs. They are
extremely noisy electrically (and fairly noisy audibly). The voltage
and current slew rates are enormous and that can capacitively or
inductively couple a fair amount of power per pulse. Normally this is
mostly constrained to the equipment cabinets but it's possible it might
damage something if it was close enough.
>
> The entire treatment room is lead shielded to protect the
> rest of the hospital.
Lead, steel, concrete and of course, good old dirt.
>
> To answer Richard's questions:
>
> The CCD was NOT damaged. The camera continues to take pictures
> with no problem. But the LCD display on the back no longer
> works. This means I've got no menus and can't do anything
> with the camera that requires them. Fortunately, the camera
> has an optical viewfinder, so I can still take photos - albeit
> with much restricted controls.
>
> Alan
--
Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting
"I'm a designated driver on the Information Super Highway"
.
- Prev by Date: Re: Canon L lenses
- Next by Date: Re: Genuine Epson Cartridges
- Previous by thread: Re: Airport and Building X-Ray machines and Digital Cameras
- Next by thread: How to use histogram?
- Index(es):
Relevant Pages
|
Loading
