الفهرس 
abstractOnly 14 pages are availabe for public view
 |  | from | 234 |  |  |
| | | from | 234 | | |
Abstract
This thesis deals with a detailled study , ana~is and comparison of electron linear accelerators ( linacs ~i’(lhe two main struct-u,res , namely , the constant Impedance Struct- ure (CIS) and the constant Gradient Structure (CGS) acoe- leratingsections •
The CGS accelerating section has the main advantages of: shorter pulse width ,output beam current ,high energy rate along the acceleratitlgsections with dense electron beam, uniform heat dissipation, and higher eleotronic efficiency. The main drawbacks of constant Gradient accelerating struc¬tures are : very high electric field at the end of acceler- ator which leads to brakedown in the case of unlo’aded structlJ.re operation condi t:ton , very small fIDperaturEE diametem at the output , large temperature gradient , anddifficu¬lty in manufacturing •
The CIS accelerating section has the advantages of uni¬formity , and consequently low cost , radial stability, and can operate with dense beam loading current witho~tfear of high electric field effect at .the end of acceler- ator. Its main disadvantage is. the low energy rate along~the accelerating section •
The studying of CIS and CGS characteristics is based on the continuity equation. The analysis show that the beam loading current and attenuation play the most important rule in determining accelerator output parameters. The detail-
led study of optimized beam loaded current and attenuation condition has shown that ; MI(i) for small values of attenuation (T~O.l) thereiderable difference between CIS and CGS operation cond¬itions either in optimizations or in zero output elec¬tric field. This operation condition is characteri¬zed by dense beam loading current and high electric fie- Id at the output. The large beam loaded current dens¬ity leads to a retarding electric field , and the high electric field rate of unload CGS accelerating section
cause El. DTake down effect at the end of accelerator
( accelerator output ).
(ii) For large values of attenuation (”’[>;0.1) , it is found that CGS accelerating section has a high energy rate than that of CIS 0 Also the O/P electric field is ~ons-
iderably reduced and that the difference between CGS and
CIS energies increases as rated electron beam current increases. The optimization process shows higher ener- gy rates for optimum attenuation and higher electrQnic efficiency rate for optimum normalized electron beam current , while that of zero output elec,tric field lies between the values of these two optimization conditions.