Laser Guiding of Electron Beams in the Advanced Test Acceleration

Correcting the beam centroid motion in an induction accelerator and reducing the beam breakup instability

“…[8,9] and has been studied extensively in both rf and induction accelerators [5,6,[10][11][12][13][14][15][16][17][18][19][20]. The Advanced Test Accelerator demonstrated the highest intensity transport in an induction accelerator to date with a 10 kA, 50 MeV electron beam utilizing phase mix damping through a laser ionized channel to suppress the BBU [12,13,21]. A summary of these previous BBU studies and recent increased intensity and vacuum transport on an induction accelerator with 64 cells is described in Ref.…”

Beam Handling And Emittance Control

“…In order to eliminate the large v-dependent (image charge)-wall potential effects, one sees from Equation ( with Elz and Elr then given in terms of 6 y(z) according to Equations (19) and (20). Since E]r = -k rElz' , the radial wall electric fields will indeed be smallor than the axial accelerating field when vr/2L is a small parameter.…”

Conditioning Electron Beams in the Ion-Focused Regime

“…We multiply the rms radius rh by 4_2 to compute the corresponding edge radius for the flat-topped profile assumed in the model. Free-expansion and wali scrape-off thus restrict the edge radius to ab(xz) < amax a Min(b, 2zo /yaao , (14) where b is the pipe radius and a 0 4 7 2rh,(O) is the initial edge radius.…”

“…Restriction (14) shows that the radius of the early beam head varies with z but not -r, assuming constant c0 /yao. In thi-region, the solution to Eq.…”

“…Preionized [12][13][14] IFR channels are especially effective at beam centering. Centering can also be achieved using passive IFR in a narrow pipe, as was first demonstrated on the Experimental Test Accelerator (ETA) at Lawrrice…”