[ RadSafe ] Re: Solar particle event

[kali1 at zahav.net.il]

  ----- Original Message ----- 
  From: kali1 at zahav.net.il 
  To: kali1 at zahav.net.il ; ROBBARISH at aol.com ; radsafe at list.vanderbilt.edu 
  Sent: Thursday, May 19, 2005 7:29 PM
  Subject: Re: Solar particle event 



    ----- Original Message ----- 
    From: kali1 at zahav.net.il 
    To: ROBBARISH at aol.com ; radsafe at list.vanderbilt.edu 
    Sent: Thursday, May 19, 2005 7:25 PM
    Subject: Re: Solar particle event 


    Dear friends,

    According to British guidelines, as outlined in "Medical and Dental Guidance Notes, a Good Practice Guide on all Aspects of Radiation Protection in Clinical Environment, Table 1.2, p. 9, 2002" in the design of a linear accelerator room, one is to consider not only the annual integral dose but also is limited by Time Averaged Dose Rate (TADR). The value of TADR for unsupervised public areas -- estimated over 8 hours, taking in account use and workload for the typical worst day case scenario (an occupancy factor of one is assumed)  --  is less than 0.5 microsievert per hour (0.05 mrem per hour).

    I would appreciate answers to two qustions:

    1.   How do British radsafers explain and justify bothering as to dose-rates where negligible doses are involved.

    2.   Why the above TADR value is not applied in the design of aeroplanes, where the TADR is some 10 times higher (Well, I don't really reccommend the use of 10 cm thick lead ceilings; I would rather stop bothering as to dose-rates in the design of linear accelerator rooms}.

    Yehoshua Kalish
    Consultant, Hod-Hasharon, Israel

      ----- Original Message ----- 
      From: ROBBARISH at aol.com 
      To: radsafe at list.vanderbilt.edu 
      Sent: Friday, February 04, 2005 9:54 AM
      Subject: Solar particle event 


      Dear friends at RADSAFE:

      For those who are interested, I have posted on my website a plot of the radiation dose rate at altitude during the large solar flare that occurred on 20 January. At its peak, the dose rate in a commercial airliner at 40,000 feet was 100 microsievert (10 mrem) per hour.

      You may see the data at:

      http://robbarish.tripod.com/events/

      I am grateful to Dr. Wallace Friedberg of the FAA for supplying the information.

      Robert Barish, Ph.D., CHP
      robbarish at aol.com