Investigation of the Increment of Transverse Instability of a Kiloampere Electron Beam in a Linear Induction Accelerator for Its Use in a Terahertz FEL

The Institute of Nuclear Physics SB RAS in cooperation with the Russian Federal Center VNIITF performs a series researches aimed at acquiring relative electron beam energy up to 20 MeV, current 2 kA, and duration 200 ns normalized emittance ca. 1000 π∙mm∙rad linear induction accelerator (LIA). In order generate beams such parameters we require thorough investigation all main sources perturbation trajectory caused by different instabilities that occur during transport acceleration high currency accelerating structure LIA. For experimental on measuring dynamics transverse oscillation beam, applied set fast transformers which are used for registration mode fields this structure. These measurements were performed 8.5 MeV 1 kA going through modes focusing magnetic size As result, registered electromagnetic field normal modules LIA, as well determined dependence amplitude these modes’ EM number module. This was compared result modeling development instability LIA using created program system. allowed us determine increment relativistic under given conditions. Based acquired results, made analysis possibility use generated ILA driver FEL generator coherent impulses THz radiation within frequency range 0.3–1.2 sub-gigawatt level power.