The MERIT HighPower Target Experiment Muon Collider Design

The MERIT High-Power Target Experiment Muon Collider Design Workshop BNL December 3 -7, 2007 Harold G. Kirk Brookhaven National Laboratory

The Collaborating Institutions U. S. Brookhaven National Laboratory Fermi National Accelerator Laboratory Oak Ridge National Laboratory Princeton Europe CERN Rutherford Appleton Laboratory MC Workshop Dec. 3 -7 Harold G. Kirk

The Neutrino Factory Target Concept Maximize Pion/Muon Production l Soft-pion Production l High-Z materials l High Magnetic Field MC Workshop Dec. 3 -7 Harold G. Kirk

The MERIT Experiment MERcury Intense Target MC Workshop Dec. 3 -7 Harold G. Kirk

Sectional view of the MERIT Experiment Secondary Containment Syringe Pump Solenoid Jet Chamber Proton Beam 4 Hg Jet MC Workshop Dec. 3 -7 3 2 1 Beam Window Harold G. Kirk

Site of experiment at CERN MC Workshop Dec. 3 -7 Harold G. Kirk

Profile of the Experiment 14 and 24 Ge. V proton beam l Up to 30 x 1012 protons (TP) per 2. 5 s spill l Proton beam spot with r ≤ 1. 5 mm rms l 1 cm diameter Hg Jet l Hg Jet/proton beam off solenoid axis l Hg Jet 33 mrad l Proton beam 67 mrad l Test 50 Hz operations l 20 m/s Hg Jet l MC Workshop Dec. 3 -7 Harold G. Kirk

Proton Beam Characteristics PS was run in a harmonic 4, 8, and 16 mode l We can fill any of the rf buckets with sub-bunches at our discretion. l Total PS fill can contain up to 30 TP. l Fast extraction can accommodate entire 2. 5 s PS fill. l Single turn extraction at 24 Ge. V l Partial/multiple extraction possible at 14 Ge. V l First Beam on Target October 17 2007 l MC Workshop Dec. 3 -7 Harold G. Kirk

Run plan for the CERN PS beam The PS Beam Profile allows for: Varying beam charge intensity from 1 TP to 30 TP. l Studying influence of solenoid field strength on jet dispersal (vary Bz from 0 to 15 T). l Study possible cavitation effects by varying PS spill structure (Pump/Probe) l MC Workshop Dec. 3 -7 Harold G. Kirk

MERIT Experiment in the TT 2 a Area Material access shaft N 2 Exhaust line Racks & electronics Personnel access Beam dump Solenoid & Hg loop MC Workshop Dec. 3 -7 Upstream beam elements (new) n Quadrupoles for final focusing n Collimator n Beam profile measurement n Beam intensity measurement Harold G. Kirk

Installed in the CERN TT 2 a Line Before Mating After Mating and Tilting MC Workshop Dec. 3 -7 Harold G. Kirk

Beam instrumentation Beam current transformer: 500 MHz sampling! Particle detector response: MC Workshop Dec. 3 -7 Harold G. Kirk

The Pump/Probe Detectors ACEM (Aluminum Cathode Electron Multiplier) Diamond +/- 10 degrees Behind dump in beam line +/- 20 degrees In beam line, upstream of target 04 June 2021 M. Palm, CERN - AB/ATB/EA MC Workshop Dec. 3 -7 13 Harold G. Kirk

Diamond Left 200 Response 131 ns Oct. 29, 2007 14 Ge. V 4 TP 10 T Field 15 m/s Hg Jet MC Workshop Dec. 3 -7 Harold G. Kirk

A 3 T Pump Pulse and a 1 TP Probe Pulse with 1 ms delay MC Workshop Dec. 3 -7 Harold G. Kirk

MERIT Beam Shots • 30 x 1012 protons/pulse!!! • 24 Ge. V • 115 k. J !!! a PS record 300 250 200 150 Hg target OFF 100 Hg target IN 50 0 3 37 39 63 9 73 83 9 8 0 3 39 83 23 9 83 43 9 83 63 9 8 8 3 39 93 03 9 93 23 9 93 43 9 9 6 Integrated beam intensity to MERIT [1013 protons] 350 MC Workshop Dec. 3 -7 Harold G. Kirk

The Optical Diagnostic Cameras Fast. Vision 1 SMD 0. 1 ms/frame 20 m/s Hg jet, 7 Tesla field Fast. Vision 2 2 ms/frame MC Workshop Dec. 3 -7 video camera Harold G. Kirk

Influence of Magnetic Field Jet Velocity is 15 m/s 0 T 10 T 5 T 15 T MC Workshop Dec. 3 -7 Harold G. Kirk

14 Ge. V Proton Beam on Hg Jet with Magnetic Field Viewport 1 at 2 ms October 26, 2007 Beam Pulse at 8: 39 pm Central European Daylight Time Viewport 3 at 26 ms Hg Jet 15 m/s Solenoid Field 5 T Proton Intensity 10 TP Harold G. Kirk Brookhaven National Laboratory

15 TP 14 Ge. V Proton Beam Oct. 27, 2007 Solenoid Field at 5 T Viewport 2 Beam 5016, Hg 15 m/s, 100μs/frame, Total 1. 6 ms MC Workshop Dec. 3 -7 Harold G. Kirk

20 TP 14 Ge. V Proton Beam Oct. 27, 2007 Solenoid Field at 10 T Viewport 2 Beam 5020, Hg 15 m/s, 100μs/frame, Total 1. 6 ms MC Workshop Dec. 3 -7 Harold G. Kirk

Viewport 3: Jet/proton interaction Shot 16014 • 14 Ge. V • 12 x 10 12 protons/pulse • B-field 10 T • 500μs/frame 1 cm Disruption Length =16. 5 cm MC Workshop Dec. 3 -7 Harold G. Kirk

The 24 Ge. V 30 TP shot Beam pulse energy = 115 k. J B-field = 15 T Jet Velocity = 20 m/s Disruption Length = 28 cm We will replace the 28 cm disruption length (2 interaction lengths) Then the jet transport time is 28 cm/20 m/s = 14 ms èRep rate of 70 Hz èProton beam power at that rate is 115 k. J *70 = 8 MW MC Workshop Dec. 3 -7 Harold G. Kirk

4 TP + 4 TP Delay Study at 14 Ge. V Single Turn Extraction 0 Delay 4 TP Probe extracted on subsequent turn 3. 2 μs Delay 4 TP Probe extracted after 2 nd full turn 5. 8 μs Delay Target supports 14 Ge. V 4 TP beam at 172 k. Hz rep rate without disruption MC Workshop Dec. 3 -7 Harold G. Kirk

Data Analysis Pipeline Disruption threshold based on proton beam characteristics Intensity variations Proton beam harmonic structure Disruption threshold based on solenoid field strength Pump/probe studies 15 TP pump + 5 TP probe with delays 2 to 700μs 24 Ge. V pump/probe studies with delays < 2μs Magnetodynamic studies disruption (filamentation) velocities quadruple distortions Proton beam spot size analysis MC Workshop Dec. 3 -7 Harold G. Kirk

The MERIT Bottom Line The Neutrino Factory/Muon Collider target concept has been validated for 4 MW 50 Hz operations. MC Workshop Dec. 3 -7 Harold G. Kirk