The MC Solenoid Capture System Solenoid Capture Workshop

The MC Solenoid Capture System Solenoid Capture Workshop Brookhaven National Lab November 29 -30, 2010 Harold G. Kirk Brookhaven National Laboratory

The Muon Collider Concept Key technical issues: Requires a multi-MW proton driver A production target system to produce copious pions A cooling system to reduce the phase space of the collected muons High gradient rf for rapid acceleration Harold G. Kirk 2

The Neutrino Factory The muons in a storage ring decay such that: μ+ e+ νe νμ and μ- e- νe νμ Further, the ν’s are projected forward with an opening angle ~ 1/γ. This gives rise to a very powerful ν beam capable of being projected over long baseline distances. Harold G. Kirk 3

Layout of a Neutrino Factory Harold G. Kirk 4

The Neutrino Factory Target Concept Maximize Pion/Muon Production l Soft-pion Production l High-Z materials l High-Magnetic Field Palmer, PAC 97 Harold G. Kirk 5

The Proton Beam Parameters Proton Beam Energy Rep Rate Bunch Structure Bunch Width Beam Radius Beam β* Beam Power 8 Ge. V 50 Hz 3 bunches, 320 sec total 2 1 ns 1. 2 mm (rms) ≥ 30 cm 4 MW (3. 125 1015 protons/sec) Harold G. Kirk 6

The Target System Target type Jet diameter Jet velocity Jet/Solenoid Axis Angle Proton Beam/Jet Angle Capture Solenoid Field Strength Free mercury jet 8 mm 20 m/s 96 mrad 27 mrad 20 T Harold G. Kirk 7

The NF Study 2 Target System Neutrino Factory Study 2 Target Concept Harold G. Kirk 8

Target System Exploded View All insertion/extraction from upstream end Locating & supporting features not shown – will require additional space Harold G. Kirk 9

MARS 15 Study of the Hg Jet Target Geometry Previous results: Radius 5 mm, θbeam =67 mrad Θcrossing = 33 mrad Harold G. Kirk 10

Multiple Proton Beam Entry Points p 0 Proton Beam Entry points p 12 jet p 4 Entry points are asymmetric due to the beam tilt in a strong magnetic field p 8 Harold G. Kirk Brookhaven National Laboratory Proton beam entry points upstream of jet/beam crossing

Optimized Meson Production X. Ding, UCLA Radius Previous baseline 0. 5 cm Beam Angle Previous baseline 67 mrad Beam/Jet Crossing Angle Previous baseline 33 mrad Production of soft pions is most efficient for a Hg target at Ep ~ 6 -8 Ge. V, Confirmation of low-energy drop-off by experiment (HARP, MIPP) highly desirable. Harold G. Kirk 12

Meson Production vs β* Meson Production loss ≤ 1% for β* ≥ 30 cm Harold G. Kirk 13

MARS Energy Deposition Studies SC 1 SC 2 SC 3 SC 4 SC 5 Air Fe. Co Hg Jet WC Shield Hg Jet Pre-Trgt STST Env (Bottle) Res Sol Hg Pool MARS 15 study of Study 2 configuration yields 38 KW energy deposition in SC 1 alone Be. Window (z=600 cm) Harold G. Kirk 14

Reconfigure SC magnets Increase the SC ID’s. Fill released volume with shielding. Total energy deposition in all SC’s reduced to ~4 k. W. But SC magnets around target are now extremely difficult. Details to be provided by N. Souchlas Harold G. Kirk 15

Key Target Challenges General Target Issues l Thermal management (~3 MW power deposited) l Shielding (SC Solenoids required) l Target integrity (Thermal Shock) l Target regeneration (50 Hz rep-rate) l 20 T environment Liquid Hg specific issues l Stable fluid flow (Nozzle performance) l Hg handling system Harold G. Kirk 16