Recalculation of shielding for the addition of a PAR

Abstract

R e c a l c u l a t i o n of S h i e l d i n g for t h e A d d i t i o n of a PAR . 0 I n t r o d u c t i o nThe s h i e l d i n g estimates f o r t h e E l e c t r o n and P o s i t r o n Linacs and t h e Booster Synchrotron, c o n t a i n e d i n t h e 1987 Conceptual Design Report (CDR) of t h e APS (ANL-87-15), have been reviewed and r e c a l c u l a t e d , along w i t h newly i n i t i a t e d c a l c u l a t i o n s of t h e r e q u i r e d s h i e l d i n g f o r t h e a d d i t i o n of a P o s i t r o n Accumulator Ring (PAR).S e v e r a l new assumptions with respect t o beam i n t e n s i t y , p r o j e c t e d l o s s e s i n t h e system, and assumed o p e r a t i o n a l t i m e have been i n c o r p o r a t e d i n t o t h e c a l c u l a t i o n s . Details of t h e p r e v i o u s c a l c u l a t i o n s , which d e s c r i b e t h e methodology used, may be found i n APS LightSource Note LS-90. 2iO S h i e l d i n g Design O b j e c t i v eThe Department of Energy's (DOE) guidance (DOE 81), concerning t h e ALARA d e s i g n g o a l for new f a c i l i t i e s , s t a t e s t h a t t h e d e s i g n o b j e c t i v e i s t o l i m i t exposures t o one-f i f t h of t h e 5-rem-per-year l i m i t given i n t h e same document.T h i s i m p l i e s a n average dose rate l i m i t of 0.5 mrem/h, based on a 40-h work week. S u f f i c i e n t c o n c r e t e as a bulk s h i e l d is used t o a c h i e v e r e a s o n a b l e g l o b a l s h i e l d i n g of a c c e l e r a t o r components f o r d i s t r i b u t e d l o s s e s i n t h e system. Localized s h i e l d i n g , which may c o n s i s t of i r o n , l e a d and/or dense polyethylene, i s used a t h i g h l o s s p o i n t s t o supplement t h e g l o b a l s h i e l d . I nsome cases, e x c l u s i o n zones may be r e q u i r e d d u r i n g t h e o p e r a t i o n a l t i m e of t h e p a r t i c u l a r component i n o r d e r t o m e e t t h e g u i d e l i n e . An a d d i t i o n a l c o n s i d e r a t i o n used i n t h e s h i e l d i n g e s t i m a t e s w a s t o l i m i tt h e dose r e c e i v e d by any i n d i v i d u a l , due t o any s i n g l e beam dump loss, t o less t h a n 100 mrem. . 0 Types Of R a d i a t i o n ConsideredDepending upon t h e energy of t h e a c c e l e r a t e d p a r t i c l e s , one o r more of t h r e e r a d i a t i o n components, each with d i f f e r i n g a t t e n u a t i o n l e n g t h s i n a g i v e n A

Annex to 7-GeV Advanced Photon Source Conceptual Design Report

“…Tunability of undulators of different periods with pure CSEM configuration using Nd-Fe-B magnets. None of the undulators provide the first-harmonic tunability from 4.7 to 14 keV recommended in Ref 4…”

“…Tunability of hybrid undulator using Nd-Fe-B magnets. The undulator with about 3.1-cm period provides the tunability range recommended in Ref 4…”