lbl accelerator def

[tdc@ehssun.lbl.gov (Ted M. de Castro)]

            Paragraph 6.a; the definitions of Accelerator and 
               Accelerator Facilities needs to be clarified.  As 
               currently stated, there is considerable ambiguity as to 
               which equipment would be covered by the Order.  This 
               clarification is essential to the cost-effective 
               implementation of this Order.  The development of a 
               concise definition of an accelerator is not 
               straightforward matter.  We believe, however, that the 
               following definition would provide significantly greater 
               clarification while allowing reasonable flexibility for 
               determining what equipment would-be defined as an 
               accelerator. 

               "An accelerator is a device employing electrostatic or 
               electromagnetic fields to impart kinetic energy to 
               molecular, atomic, or sub-atomic particles.  There are, 
               however, many types of electronic equipment which meet 
               this basic definition which are normally not considered 
               as accelerators because of their specific application, 
               maximum energy, or limited ability to produce significant 
               external ionizing radiation fields.  Devices to be 
               subject to the requirements of this Order are those which 
               are likely to routinely create a high radiation area due 
               to the accelerated beam or interactions therewith, where 
               portions of a whole body (as opposed to extremities) 
               could be exposed. This wording is meant to exclude those 
               situations where the radiation is adventitious due to the 
               high voltage power supply and NOT the accelerated 
               species.  However, because there may remain ambiguity in 
               interpretation of the above, the following devices are 
               excluded from the requirements of this Order:

               a. Electronic equipment which can accelerate particles to 
                 a maximum of 1 MeV and which are not likely to produce 
                 radiation fields >100 mrem/h at a distance of 30 cm 
                 from the exterior of the machine under maximum 
                 operating parameters.The exterior of the machine is 
                 defined as outside any materials inherent to the 
                 contruction of the machine but inside any secondary 
                 structures intended primarily for shielding such as a 
                 vault, cave or other shielding enclosure

               b. Equipment which accelerates electrons  for the sole 
                 purpose of producing x-rays.  This includes most 
                 analytical, radiographic, and medical x-ray machines. 

               c. Miscellaneous electronic devices which can accelerate 
                 particles to a maximum of 1 MeV and produce ionizing 
                 radiation as a by-product of their primary function. 
                 Such equipment includes most video display terminals, 
                 electron microscopes, electron beam welders, ion 
                 implant devices, electron beam devices primarily used 
                 for melting and refining metals, and high voltage power 
                 supplies. 

                 Because of the wide variety of electronic equipment 
               that can accelerate particles and the even wider spectrum 
               of applications, the above definition is only intended to 
               provide a basic guideline of what electronic equipment 
               will be considered as an accelerator  It is assumed that 
               individual equipment could be evaluated on a case-by-case 
               basis to establish whether adherence to the requirements 
               of this Order is appropriate.  For example, if the 
               contractor believes that electronic equipment not subject 
               to the above exclusions should not be considered as an 
               accelerator by reason of specific application, equipment 
               configuration, or operating parameters, the submission of 
               an exception request as provided for in Paragraph 7.a.6 
               would be appropriate."