▁insert ion ▁devices . ▁The ▁insert ion ▁devices ▁cause ▁the ▁electrons ▁to ▁und ulate ▁and ▁it ▁is ▁their ▁sudden ▁change ▁of ▁direction ▁that ▁causes ▁the ▁electrons ▁to ▁emit ▁an ▁exception ally ▁bright ▁beam ▁of ▁electro - mag net ic ▁radiation , ▁br ighter ▁than ▁that ▁of ▁a ▁single ▁b end ▁when ▁travel ing ▁through ▁a ▁b ending ▁magnet . ▁This ▁is ▁the ▁syn ch ro tr on ▁light ▁used ▁for ▁experiments . ▁Some ▁be aml ines , ▁however , ▁use ▁light ▁sole ly ▁from ▁a ▁b ending ▁magnet ▁without ▁the ▁need ▁of ▁an ▁insert ion ▁device . ▁ ▁The ▁electrons ▁reach ▁this ▁high ▁energy ▁via ▁a ▁series ▁of ▁pre - ac cel er ator ▁stages ▁before ▁being ▁inject ed ▁into ▁the ▁ 3 ▁Ge V ▁storage ▁ring : ▁ ▁an ▁electron ▁gun ▁– ▁ 9 0   ke V ▁ ▁a ▁ 1 0 0   Me V ▁linear ▁acceler ator ▁ ▁a ▁ 1 0 0   Me V ▁– ▁ 3   Ge V ▁boost er ▁syn ch ro tr on ▁( 1 5 8   m ▁in ▁circum ference ). ▁ ▁The ▁Diam ond ▁syn ch ro tr on ▁is ▁hous ed ▁in ▁a ▁silver ▁tor oid al ▁building ▁of ▁ 7 3 8 ▁m ▁in ▁circum ference , ▁covering ▁an ▁area ▁in ▁excess ▁of ▁ 4 3 , 3 0 0 ▁square ▁metres , ▁or ▁the ▁area ▁of ▁over ▁six ▁football ▁pitch es . ▁This ▁contains ▁the ▁storage ▁ring ▁and ▁a ▁number ▁of ▁be aml ines , ▁with ▁the