Maps for Electron Clouds: Application to LHC Conditioning

The elec­tron cloud driv­en ef­fects can limit the abil­i­ty of re­cent­ly build or planned ac­cel­er­a­tors to reach their de­sign pa­ram­e­ters. The sec­ondary emis­sion yield re­duc­tion (called "scrub­bing") due to the fact that the elec­trons of the cloud hit the vac­u­um cham­ber wall, mod­i­fy­ing its sur­face prop­er­ties, may min­i­mize any dis­turb­ing ef­fects of the cloud to the beam. The de­pen­dence of "scrub­bing" ef­fi­cien­cy on beam and cham­ber pa­ram­e­ters can be de­duced from e-cloud sim­u­la­tion codes mod­el­ing the in­volved physics in full de­tail. In this com­mu­ni­ca­tion we pre­sent a gen­er­al­iza­tion of the map for­mal­ism, in­tro­duced in*,**, for the anal­y­sis of elec­tron flux at the cham­ber wall with par­tic­u­lar ref­er­ence to the ex­plo­ration of LHC con­di­tion­ing sce­nar­ios. Sim­u­la­tions based on this for­mal­ism are or­ders of mag­ni­tude faster com­pared to those based on stan­dard par­ti­cle track­ing codes.