Dependence of the Emittances of the Fermilab Injectors on Intensity

Abstract

This paper reports the dependence of the emittance of the Main Ring injected beam on Booster intensity. The intensity was changed in two different ways: by changing the number of turns injected into the Booster using the normal Hcharge-exchange injection and by changing the intensity of the Linac itself by varying the phase of the buncher.The measured emittance of the Linac beam was also compared, assuming adiabatic shrinkage, to the emittance of the Main Ring beam measured while injecting one turn into the Booster.

Studies of Beam Intensity Effects in Fermilab Booster Synchrotron

“…Nonlinear dependence of the extracted Booster beam emittance on N p was reported in many previous measurements with MultiWire profile monitors -see, e.g. [52,55,56]. The Booster Ionization Profile Monitors operating in the ion collection mode without external magnetic field are known to be extremely valuable tools for fast beam size diagnostics of the circulating beam during acceleration [44,57,58].…”

“…Booster is a lynch pin of the Fermilab proton accelerator complex and its transmission efficiency has always been subject of continuous monitoring and several studies for almost four decades -see, e.g. [52][53][54]. Naturally, the Booster performance at present significantly exceeds that of the past -compare current transmission ∼95% at N p = (4.5 − 5) • 10 12 with that of ∼(70-75)% at N p = (3.5 − 4) • 10 12 in 1980s and 1990s.…”