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- From: dvsg0223@uxa.cso.uiuc.edu (David Salamon)
- Subject: Re: Airport X-Rays
- References: <22754@oasys.dt.navy.mil> <4836@unixhub.SLAC.Stanford.EDU> <1992Jul29.084952.12730@bronze.ucs.indiana.edu> <Bs5o1E.2G9@news.larc.nasa.gov>
- Message-ID: <Bs5s3E.68p@news.cso.uiuc.edu>
- Sender: usenet@news.cso.uiuc.edu (Net Noise owner)
- Organization: University of Illinois at Urbana
- Date: Wed, 29 Jul 1992 16:21:08 GMT
- Lines: 26
-
- kludge@grissom.larc.nasa.gov ( Scott Dorsey) writes:
-
- >X-rays will not harm magnetic tapes at all. However, the enormous magnets
- >that X-ray tubes use to focus their electron beam might very well damage
- >tapes.
-
- I seriously doubt that there is any focussing of the eletrons at all. I think
- there is simply a high voltage between a small hot cathode and a larger
- target. If the target is flat (for example) and much larger than the cathode,
- then the electrons will follow the field lines and all impact roughly
- perpendicular to the surface. No focussing necessary. After all, we don't
- care WHERE the electrons hit the target, just that they hit with the correct
- momentum.
-
- As others have mentioned, however, the high voltage is produced by a
- transformer, which will create a magnetic field. Metal shielding of course
- will not stop this field, so it could affect magnetic media. It all
- depends on where the transformer is placed with respect to the conveyer belt.
-
- David
-
- --------------------------------------------------------------
- David Salamon Physics Graduate Student (Slave)
- d-salamon@uiuc.edu University of Illinois
- --------------------------------------------------------------
-
-