MANX, A 6-D Muon Cooling Demonstration Experiment

Abstract

Most ionization cooling schemes now under consideration are based on using many large flasks of liquid hydrogen energy absorber. One important example is the proposed Muon Ionization Cooling Experiment (MICE), which has recently been approved to run at the Rutherford Appleton Laboratory (RAL). In the work reported here, a potential muon cooling demonstration experiment based on a continuous liquid energy absorber in a helical cooling channel (HCC) is discussed. The original HCC used a gaseous energy absorber for the engineering advantage of combining the energy absorption and RF energy regeneration in hydrogen-filled RF cavities. In the Muon And Neutrino eXperiment (MANX) that is proposed here, a liquid-filled HCC is used without RF energy regeneration to achieve the largest possible cooling rate in six dimensions. In this case, the magnetic fields of the HCC must diminish as the muons lose momentum as they pass through the liquid energy absorber. The length of the MANX device is determined by the maximum momentum of the muon test beam and the maximum practical field that can be sustained at the magnet coils. We have studied a 3 meter-long HCC example that could be inserted between the MICE spectrometers at RAL.

New experiments with antiprotons

“…The latter proposal is to measure a slow (≈ 1 km/s) antihydrogen beam, formed in a Penning trap, using an atom interferometer composed either of material gratings (giving δ g/g ∼ 10 −4 ) or laser beams [24] (δ g/g ∼ 10 −9 ). Deceleration for trapping can be accomplished down to ≈ 400 MeV in the Main Injector, followed by an "antiproton refrigerator" [25], reverse linac, or small synchrotron [23].…”

Muon acceleration: introduction and R&D on limiting technologies

“…Intense 6D cooling for the Muon Collider is not yet under experimental study, but is being modeled and studied with theoretical and computation tools. Concepts under study include the ring-FOFO or "Guggenheim", the Helical Cooling channel [11] and Parametric Resonance Ionization Cooling [12]. Figure 4 shows schematic concepts for the Guggenheim (left) and a helical solenoid (right) that is being developed for a proofof-principle test of components for the helical cooling channel.…”

New results on the π+π− electroproduction cross sections off protons

“…Measurements of the π + π − electroproduction cross sections represent an important part of the efforts in the N * program with CLAS [1,2]. This program is focused on the evaluation of most excited proton electrocouplings at photon virtualities (Q 2 ) up to 5.0 GeV 2 ,which will allow us to pin down the active degrees of freedom in the N * structure at different distance scales, and to access the non-perturbative strong interaction mechanisms that are responsible for the formation of the ground and excited nucleon states [3,4].…”