Fluidised powder target research A potential target technology for both a Superbeam and a neutrino factory CJ Densham, O Caretta, P Loveridge STFC Rutherford Appleton Laboratory

Is there a ‘missing link’ target technology? Some potential advantages of a flowing powder: Resistant to pulsed beam induced shock waves Favourable heat transfer Quasi-liquid Few moving parts Mature technology Areas of concern can be tested off-line Open jets SOLIDS LIQUIDS Monolithic Flowing powder Contained liquids Segmented

Schematic layouts of flowing powder targets for neutrino facilities Superbeam target - contained within pipe Neutrino factory target - open jet configuration used in test rig on day 1 (for MERIT comparison) (1) pressurised powder hopper, (2) discharge nozzle, (3) recirculating helium to form coaxial flow around jet, (4) proton beam entry window, (5) open jet interaction region, (6) receiver, (7) pion capture solenoid, (8) beam exit window, (9) powder exit for recirculation, (10) return line for powder to hopper, (11) driver gas line

Summary of Operation Powder –Rig contains 100 kg Tungsten –Particle size < 250 microns Total ~8,000 kg powder conveyed –90 ejection cycles –Equivalent to 15 mins continuous operation Batch mode –Test out individual handling processes before moving to a continuous flow loop

Summary of Operation Powder –Rig contains 100 kg Tungsten –Particle size < 250 microns Total ~8,000 kg powder conveyed –90 ejection cycles –Equivalent to 15 mins continuous operation Batch mode –Test out individual handling processes before moving to a continuous flow loop 1 1. Suction / Lift

Summary of Operation Powder –Rig contains 100 kg Tungsten –Particle size < 250 microns Total ~8,000 kg powder conveyed –90 ejection cycles –Equivalent to 15 mins continuous operation Batch mode –Test out individual handling processes before moving to a continuous flow loop Suction / Lift 2. Load Hopper

Summary of Operation Powder –Rig contains 100 kg Tungsten –Particle size < 250 microns Total ~8,000 kg powder conveyed –90 ejection cycles –Equivalent to 15 mins continuous operation Batch mode –Test out individual handling processes before moving to a continuous flow loop Suction / Lift 2. Load Hopper 3. Pressurise Hopper

Summary of Operation Powder –Rig contains 100 kg Tungsten –Particle size < 250 microns Total ~8,000 kg powder conveyed –90 ejection cycles –Equivalent to 15 mins continuous operation Batch mode –Test out individual handling processes before moving to a continuous flow loop Suction / Lift 2. Load Hopper 3. Pressurise Hopper 4. Powder Ejection and Observation

Control Interface Fully automated control system –Process control –Data 20 Hz –Hard-wired safety interlocks Control System Interface (MATLAB) Experiment notes System indicator window Warning messages Emergency stop Suction settings Ejection settings

Post Processing Two-page Report - Microsoft Word Automatic report generator –Records experiment settings –Graphs the data –Generates a Microsoft word document for each cycle Post-processing user interface - Matlab

Contained stable jet Contained unstable jet

Particle Image Velocimetry velocity distribution required to determine bulk density Ottone Caretta, Oxford, Nov 09

Variations in the flow rate – typical 2bar ejection How much material would a proton beam interact with? Bulk density? Is the amount of material in the nozzle (or jet) constant? Ottone Caretta, Oxford, Nov 09

Optimise gas lift system for CW operation Carry out long term erosion tests and study mitigation Investigate low-flow limit Study heat transfer between pipe wall and powder Demonstrate shock waves are not a problem –Use of CERN test facility for shock wave experiment on a powder sample in helium environment Demonstrate magnetic fields/eddy currents are not a problem –Use of high field solenoid? Investigate active powder handling issues (cf mercury?) Flowing powder target: next stages