Radiation-induced acoustic cavitation; apparatus and some results

Equipment and techniques for acoustic cavitation w o ~k are desc ribed . . The tes t liquid and its eontainer form part of a se lf sustaining programmable oscIllator. EmphasIs IS laId on the treatme nt of the liquid necessa ry to yield re producible res ults after artificial nucl ea tion ,. especially b y ne utrons , a-recoi ls, and fi ss ion. With ne utrons , for instance, th e ca vitatIOn rate rI ses rapI~ly WIth acoustIc (negativ e) press ure, and at fix ed pressure is proportional to ne utron flux . The ca vItat~on events are ra~dom, and no ap prec ia bl e indu c t.ion or decay tim es are obse rve d. Each cav itatIOn anses from the actIOn of a s in"l e ne ut.ron (or a -recoil , or fi ss ion). The ca vit.atio n " thres ho ld " (rou ghly negative press ure below whi c l ~ cavital ion is rare) is hi ghl y variab le fro m liquid to liquid. Thres holds at about room temperature for liquids irradi a t.ed with 10 MeV ne utrons ranged from 1 to 2 bars for n-pentane, e ther, and fre on 113 to ove r 50 ba rs for wate r.