Filterless Fast Momentum Cooling

The \(\bar p\) accumulation scenario proposed at Fermilab involves precooling at p production energy (4.5 GeV) and deceleration to freezer ring energy (200 MeV). This required a large factor (≳ 125) of momentum cooling. Optimization of cooling with these constraints has led to the conception of a new possible method of momentum cooling, which does not require a stub filter. The system operates in a “good mixing” regime. Cooling proceeds simultaneously with deceleration from freezer energy. We present a detailed comparison of this new method to fixed energy filter cooling, showing the rates achievable to be comparable. Several corollary benefits unique to this approach are discussed: (1) The possibility of using much simplified pick-up structures at higher, microwave frequencies and (2) the flexibility to perform transverse cooling simultaneously, at a rate greatly enhanced over what would be possible at fixed energy along with cooling.