Beam Losses and Background Loads on Collider Detectors Due to Beam-Gas Interactions in the LHC

With a ful­ly-op­er­a­tional high-ef­fi­cient col­li­ma­tion sys­tem in the LHC, nu­cle­ar in­ter­ac­tions of cir­cu­lat­ing pro­tons with resid­u­al gas in the ma­chine beam pipe can be a major sources of beam loss­es in the vicin­i­ty of the col­lid­er de­tec­tors, re­spon­si­ble for the ma­chine-in­duced back­grounds. Re­al­is­tic mod­el­ing of elas­tic and in­elas­tic in­ter­ac­tions of 7-TeV pro­tons with nu­clei in the vac­u­um cham­ber of the cold and warm sec­tions of the LHC ring - with an ap­pro­pri­ate pres­sure pro­file - is per­formed with the STRUCT and MARS15 codes. Mul­ti-turn track­ing of the pri­ma­ry beams, prop­a­ga­tion of sec­on­daries through the lat­tice, their in­ter­cep­tion by the ter­tiary col­li­ma­tors TCT as well as prop­er­ties of cor­re­spond­ing par­ti­cle dis­tri­bu­tions at the CMS and ATLAS de­tec­tors are stud­ied in great de­tail and re­sults pre­sent­ed in this paper.