Bremsstrahlung exposure

Discussion in 'Off-Topic' started by Hypatia's Protege, Jan 22, 2016.

  1. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    Hello @JoeJester

    Not wishing to (further:oops:) hijack @Wendy 's thread, I thought to post my response/inquires here:

    That's extremely low for a Coolidge tube but perilously high for an incidental emitter!:( --- I'm assuming, from the dose rate and your reference to a 'push pull' arrangement, that the tubes in question were incorporated in the PA of a high-power radio transmitter, is that correct? -- If so, what was the applied anode (plate) EMF?

    Were the tubes of external anode (ceramic) or glass construction?

    With genuine interest

    Best regards
    HP
     
    Last edited: Jan 22, 2016
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    I looked this up on Google. Still don't know what it is, but seems to be related to x-rays?
     
    Hypatia's Protege likes this.
  3. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    Hello - and thanks for your interest!:)

    Bremsstrahlung (i.e. 'braking radiation') is descriptive of electromagnetic radiation corollary to deceleration of charge (as, for instance, electrons striking the anode of a Coolidge tube) -- Note that the term is likewise applicable to radiation secondary to deceleration of other (charged) 'particles', other accelerator topologies, and certain natural phenomena...

    The term X-Radiation is applied to bremsstrahlung and characteristic radiation having photon energies > 100eV (30keV to 10MeV being the range for medical application) -- Albeit much higher PEs have been attained in the lab...
    The term Gamma Radiation is applied to electromagnetic radiation having photon energies >30keV secondary to any naturally occuring phenomena whatever...

    Note that, as a practical matter, the sole distinction between 'Gamma' and 'X' radiation is the nature of the source (i.e. 'natural' vs. 'artificial' respectively) hence the terms are ambiguous...

    For example, bremsstrahlung (of the requisite PE) corollary to collision of electrons in a particle accelerator (e.g. a Coolidge tube) is termed X-Radiation -- whereas bremsstrahlung corollary to deceleration of 'Betas' (electrons by any other name!) is termed "Gamma radiation" -- even where the respective PEs are identical! --- 'Tis but another in an endless litany of examples underscoring humanity's fixation with identity!:confused: -- In this case, to the extent of insistence upon distinction despite absence of difference?!!!!:confused::eek::rolleyes:

    Again, many thanks for your interest! -- and very best regards!
    HP:)

    PS -- It occurs to me that the discipline of astronomy uses the term 'X-rays' to describe ionizing electromagnetic radiation secondary to certain natural phenomena --- (Dissension amongst the ranks - Wot?;))
     
    Last edited: Apr 9, 2016
    #12 and BR-549 like this.
  4. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,073
    3,856

    The only 'exposure' (pun intended) I've had to BR is at Brookhaven National Synchotron Light Source. We all had to leave the beam room as they brought the beam on line and ACCELERATED the electrons. This was because the deflection of the beam magnets were actually a deceleration of the electrons and braking would occur. Although the beam keeps the cycling electrons focused while in steady state, that BR is much less than the radiation emitted while the electrons are accelerated from a standing start and the big forces to group and focus the beam.

    The beam was running for 3 to 12 hours when I was there. I think they are able to keep it running much longer now.
     
    Last edited: Jan 22, 2016
    Hypatia's Protege likes this.
  5. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    Yupper! Such is the nature of synchrotrons! -- a topology dear to my heart (and to @Aleph(0) 's bank account :D)!

    As an aside - a common question posed by those of 'Newtonian persuasion' takes the form of: "What's the difference between acceleration and deceleration" -- at which juncture I gently aquatint them with their Newtonian 'dark side' -- which is lotz nicer than @Aleph(0) 's reaction!:eek::eek::eek: --- Thank you @GopherT for getting it right!!! -- Thus it is that we are spared The Wrath of The Aleph for another day (hopefully:rolleyes:)

    OBTW: Please forgive me for this:
    ---Officiousness added---
    I know!:oops: But hey! As 'the club bombast', I've certain 'responsibilities' to uphold:D

    Very best regards
    HP:):):)


    PS --- Hey @Aleph(0) I know I don't need to say this - however I feel that I must: It's all kwel...K?:)
     
    Last edited: Jan 22, 2016
  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,164
    The irritation was caused by high power vacuum tubes operating between 15kV and 22kV.

    So, it was incidental contact.

    I've posted the holy shit video here in the past.

    Leukemia was diagnosed 20 years after my friend was assigned to that unit. In fact, almost everyone assigned to that unit has died from irradiation type diseases. That made it a cluster.

    The report is online at loran-history.info

    The tubes at my friend's unit were water cooled anodes with glass envelopes, pictured below. The other's were air cooled anodes with glass envelopes. Frequncy was 100 kHz and others were 1.8 - 2.0 KHz.

    The filaments were thoriated tungston.

    [​IMG]
    picture provided by Pool-Henning
    vacuum tubes were at Lorsta Eide Norway

    on edit: added photo credit.
     
    Last edited: Jan 22, 2016
    Hypatia's Protege likes this.
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,073
    3,856
    Point taken.

    Now my turn. Why did you make this post in "off-topic" rather than physics (BR) or General Science (Exposure)? Do you view this topic to be in line with the other pensées du jour posted here?
     
    Hypatia's Protege likes this.
  8. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    This underscores the sadly under-appreciated fact that 'soft' (i.e. low PE) X-Rays tend to exhibit a greater degree of inimicality (to life) than commensurate exposures to 'harder' emissions (owing to greater absorption of the former) --- A fact not compensated for by 'dose equivalence' formulae:( ---- That said, 3 REM/Hr is much too much incidental emission under any circumstances!:(

    Do you have a link to the specific incident?

    Very best regards
    HP
     
    Last edited: Jan 22, 2016
  9. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    Because it was 'forked' from another thread in OT (as noted in the OP) --- Moreover, I'm a bit 'skittish' as regards the appropriacy of any discussion not directly relating to electronics -- Thus I regard 'Off Topic' as reasonably 'safe' where such doubt is perceived -- Population by 'thoughts of the day', anecdotes and vacation snaps not withstanding!:rolleyes::D

    Very best regards
    HP:)
     
    Last edited: Jan 23, 2016
  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,164
  11. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    @JoeJester --- Thanks for the image!

    ---Emphasis added---
    I knew that LORAN was low frequency -- But I didn't know it was AF!o_O ---'Tho I've heard tell of submarine communication facilities operating at ELF (as well)...

    Ironically, the tubes in your image bear a superficial (and, so it would seem, eerie) resemblance to Coolidge RAs: (An example of which is pictured below)
    --Oversize image deleted--

    Very best regards
    HP
     
    Last edited: Apr 15, 2016
  12. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,073
    3,856
    HP,

    It appears that your electronics-related interests encompass re-creating 1920's and 1930's era high voltage experiments. Is this this your occupation or your hobby?
     
  13. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    I would say my passion (But hobby/avocation will do:D) --- Actually, it's not so much a 'retro thing' as it is a 'bullet proof thing' -- and, truth be told, X-Ray generation is far more the 'point' than EHT, per se...:cool:

    Many thanks for your interest!:)

    Best regards
    HP
     
  14. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,164
    Loran-A was 1.8 MHz to 2.0 MHz.

    Omega Navigation System was 10 kHz to 12 kHz, and the lowest of the RF systems to my knowledge. There were 8 stations covering the whole world.

    GWEN was a LF communications system (Ground Wave Emergency Network).

    I do know of some LF systems used for sub communications, as well as doing some pulse position modulation of the Loran-C signals.
     
    Last edited: Jan 22, 2016
    Hypatia's Protege likes this.
  15. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    I talked with several tech who worked on ELF units back in the 70's. They had to put an acrylic cylinder around it because of the coronal discharge. The coils and whatnot actually glowed.
     
    #12 and Hypatia's Protege like this.
  16. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,164
    You could stand between the transmitters with a four foot fluorescent tube in your hand and it would energize.

    I remember corona ring on some of the f7012 tubes but that was in the LF band and those rings disappeared on later manfactured tubes.
     
    Hypatia's Protege likes this.
  17. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    Indeed! Corona starts to become a problem wherever EMFs exceed ≈ 12kV (DC or Peak)... And is quite troublesome above 35kV where immersion in dielectric oil is not an option -- Not only does corona pollute indoor air (with O3 and NO2), damage insulation and pose an increased flash-over/arc-flash hazard - but it represents significant loss! -- Much more than suggested by its deceptively 'gentle' glow:mad:

    Best regards
    HP:)
     
  18. #12

    Expert

    Nov 30, 2010
    16,355
    6,852
    It's not very deceptive after one has cleaned 6 feet of the floor with his buttocks.:D

    So...what about those gasses we discussed in PM? Any utility for your purpose?
     
    JoeJester likes this.
  19. Hypatia's Protege

    Thread Starter Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    I'm talking corona not arc flash:eek:

    Please refresh my memory:cool:

    Best regards
    HP
     
  20. #12

    Expert

    Nov 30, 2010
    16,355
    6,852
    Sulfur hexa-fluoride?
    Relatively inert element with (6) valence 1 partners. Dense (heavier than air) gas at room temperature. Very much an insulator. Converts to the 10 partner toxic when energy is added.

    Gawd, I'm bad at chemistry!
     
    Last edited: Jan 22, 2016
Loading...