The SESAME pre-injector is a classical 22 MeV Microtron (MM22) that emits and accelerates the electrons up to 20MeV as required. The electrons are extracted from the LaB6 crystal using a 4µs long and 63kV magnitude voltage pulse and injected into the 3GHz RF cavity which accelerates them at a rate ~ 0.535 MeV each turn using a 4µs long and 45kV magnitude RF pulse. After ~ 39 turns, the 20MeV electrons are extracted from the Microtron using a ‘deflection tube’ and transferred to the Booster through the transfer line TL1.

The main parameters and parts of the Microtron are listed and shown respectively by the Table and Figure below.


Table 1
Parameter Value
Extractable energy (MeV) 5.3 - 22.5
Extractable turns 10 - 42
Energy gain / turn (keV) 535
Energy spread (FWHM) (keV) 35
Magnet field (T) 0.112
Magnet diameter (m) 2.22
Pole diameter (m) 1.8
Gap (m) 0.11
Magnet weight (Ton) 11
Microwave frequency (GHZ) 3
Microwave peak power (MW) 2
Electron pulse duration (µs) 2
Beam power (kW) @ 21MeV 400
Beam power (kW) @ 10MeV 600
Bp (T.m) @ 21 MeV 0.071
ɛx for 100% of the beam @ 21MeV (mm.mard) 3.8π
ɛz for 100% of the beam @ 21MeV (mm.mard) 12.8π



Figure 2
SESAME’s microtron