HRMT24 BeGrid – Technical Review P. Hurh 1, B. Hartsell 1, B. Zwaska 1, K. Ammigan 1, C. Densham 2, A. Atherton 2, M. Fitton 2, J. O’Dell 2, T. Davenne 2, P. Loveridge 2, O. Caretta 2, S. Roberts 3, V. Kuksenko 3, M. Calviani 4, R. Losito 4, D. Hovarth 4 1 Fermi National Accelerator Laboratory Batavia, IL 60510, USA 2 STFC Rutherford Appleton Laboratory Harwell Oxford, Didcot, OX11 0QX, UK 3 University of Oxford Oxford, OX1 3PH, UK 4 CERN CH-1211 Geneva 23, Switzerland

Overview  Introduction  Experiment design  Operational process  Risk analysis  Residual activation study 2HiRadMat Technical Board Review15/10/2014

Introduction Motivation To help successfully design and reliably operate beryllium windows and targets for future high intensity particle accelerator facilities, by identifying failure mechanisms of beryllium under high intensity beam conditions Objectives  explore the onset of failure modes of various beryllium grades under controlled conditions at very high localized strain rates and temperatures  identify potential thermal shock limits of different beryllium grades  compare experimental measurements to highly non-linear damage/failure numerical simulations for validation of material models 3HiRadMat Technical Board Review15/10/2014

Test Matrix 1 1 Ammigan, K. et al., “A beryllium material test experiment at CERN HiRadMat facility”, 9th International Workshop on Neutrino Beams and Instrumentation, September 23-26, mm40mmThin discs“Slugs” HiRadMat Technical Board Review15/10/2014

Experiment Design Concept 5 Thin Discs Slugs HEPA Filter Pump Beam Airflow Sample containment boxes Outer chamber  Double containment: i.Sealed sample containment boxes ii.Outer chamber with beam entry/exit holes  Outer chamber entry/exit holes 15mm diameter (or smaller)  Active pumping of outer chamber volume  Incoming air speed estimated ~3 m/s  Detachable HEPA filter  Method of sealing outer chamber after experiment and in event of emergency. HiRadMat Technical Board Review15/10/2014

Experiment Layout Pump: 18m 3 /hr 48V – 7A 200mbar suction head Experiment chamber HEPA Filter Dry Disconnects Lift Table Camera Mirror Interface plate Beam 6HiRadMat Technical Board Review15/10/2014

Experiment Chamber Exterior Shutter system Optical windows Wedge Interface plate with alignment screws Air outlet with integrated pressure switch Electrical feedthroughs Experiment chamber dimensions: 0.65m (L) x 0.35 (W) x 0.3 (H) 7HiRadMat Technical Board Review15/10/2014

Interior layout Pressure Relief Valves Vertical Base Plate Thin disc containment box Slug containment box GAFCHROMIC foil Horizontal Base Plate 8HiRadMat Technical Board Review15/10/2014

Support blocks Electrical feedthroughs Ports on VBP for electrical connections to slug containment boxes 9 Interior layout HiRadMat Technical Board Review15/10/2014

Slug Containment Box Sample attachment plate Electrical feedthrough Glassy Carbon + Graphite windows Pressure relief Optical window Slug tray Glassy Carbon/Graphite Baffle plate Containment box cover 10HiRadMat Technical Board Review15/10/2014

Thin Disc Containment Box Thin discs EBSD samples Glassy Carbon + Graphite window Pressure relief Optical window Al rods End plate Spacer Disc holder Be disc 11HiRadMat Technical Board Review15/10/2014

Instrumentation List 12 InstrumentationPurposeQuantity Resistive strain gagesDynamic strain response of slugs30 RTD sensors (PT100)Temporal temperature of slugs5 LDV*Radial velocity/displacement of slugs1 High resolution still camera* Monitor slug condition before and after pulses. 1 Gafchromic foil and cameraBeam alignment and positioning1 Lighting Provide illumination for acquiring camera images 1 Pump Draw air out of outer chamber via HEPA filter 1 *LDV and high resolution camera will be placed in low radiation bunker, upstream of experimental area (~ 40 m). Accurately aligned mirrors will be used to send and reflect the laser beam back to vibrometer. HiRadMat Technical Board Review15/10/2014

Beryllium Mass Estimate 13 Be grade Thickness (mm) Quantity Mass (g) Total mass (g) S-65F (VHP) S-200F (VHP) S-200FH (HIP) PF TOTAL HiRadMat Technical Board Review15/10/2014

Materials and Mass Estimate MaterialComponentMass [kg]QuantityTotal Mass [kg] Aluminium Al 6082 Interface Plate Outer chamber HBP VBP Support Blocks Slug Containment Boxes Slug Trays Disc Containment Boxes Disc Sample Holders Rod discs Rod EBSD End Plates Foil Holder Total Mass [kg] Toughened Glass Outer Window Outer Window Thin Disc window Slug window Total Mass [kg] 2.38 Glassy Carbon Beam windows7.21E Baffle plates8.06E Total Mass [kg] 0.10 Graphite R7650 Beam windows9.98E Overall Mass [kg] HiRadMat Technical Board Review15/10/2014

 Manufacture and assembly of experiment apparatus (RAL)  CMM surveying of samples relative to vertical base plate (RAL)  Characterisation of thin disc samples for EBSD PIE (Oxford)  Testing of camera and remote systems.  Strain gauge and PT100 installation and testing with DAQ system (TBD)  Transport of pre-assembled apparatus to CERN.  Installation on experiment table at CERN.  Surveying on experiment table.  Installation on test stand in experiment tunnel. Operational Process: Experiment Preparation 15HiRadMat Technical Board Review15/10/2014

Experiment Operational Procedure 16 Inspect pump diagnostic Execute pilot beam shot Activate camera directed at slug and inspect slug condition Activate camera directed at foil and inspect beam alignment Deactivate pump Continue? End experiment Move to next array Start experiment Troubleshoot pump Execute beam shot Close shutters Continue? HiRadMat Technical Board Review15/10/2014

Beam pulse list:  Total protons = 2.00e14  Note list does not include low intensity pilot pulses 17 Experiment Operational Procedure HiRadMat Technical Board Review15/10/2014

 Seal box by activating shutter system to close any open beam holes in the outer chamber.  Transport to cool down zone.  Cool down period  Detach filter for analysis  Visually inspect samples  Remove outer chamber and extract thin disc sample boxes.  Package containment boxes in shielding flask for transport to Oxford, UK. Operational Timeline: Post-irradiation 18HiRadMat Technical Board Review15/10/2014

Containment Box Pressure Increase: CFX Study 2 19 Thin disc containment box geometry Section through thin disc containment box showing convection Section through slug containment box showing convection Pressure increase ~125Pa 2 Davenne, T.,, 13 th October 2014 Volume average pressure in slug array Pressure increase ~180Pa HiRadMat Technical Board Review15/10/2014  Full intensity pulse energy deposition  Temp jump of ~10K  Pressure increase of ~180Pa in slug box

Risk Assessment 20 Beryllium Handling: Hazard:  Ingestion, skin and eye irritation. Precautions:  Beryllium samples remain contained in sealed containment boxes throughout presence at CERN.  Release to external environment prevented by:  Double containment  Active pumping of outer chamber.  Online diagnostics (pressure switch, camera systems)  Disassembly procedure and diagnostics.  Extraction of samples from containment box at Oxford or CCFE, UK. HiRadMat Technical Board Review15/10/2014

Radiation Protection Risk Assessment 21 Main points: Minimise activation  Aluminium construction  Minimise sample size and number Containment:  Double containment  Minimise sample number and size  Experiment chamber sealable after experiment in event of emergency  Online diagnostics: monitor beam alignment, slug condition and pump activity.  Beryllium remains contained in sealed containment boxes throughout presence at CERN. Post experiment:  Detachable filter and visual inspection  Minimise contact time: quick release pins  Extraction of samples from containment box at Oxford or CCFE, UK. HiRadMat Technical Board Review15/10/2014

 Activation study performed on thin disc and slug containment boxes  Simplified FLUKA geometry:  Screw holes, grooves and DSUB connector omitted  Hex screws simplified to a cylinder Activation Study 3 3 Horvarth, D., Calviani, M. “BeGrid HiRadMat Test: Residual activation”, 6 th October HiRadMat Technical Board Review15/10/2014

Used materials: Al6082 (composition w%): Si –1.3% Fe –0.5% Cu –0.1% Mn–1.0 % Cr –0.25% Mg –1.2% Zn –0.2% Ti–0.1% Al –95.35% ρ= 2.7 g/cm3 Glassy Carbon: Pure carbon ρ= 1.5 g/cm3 Beryllium Irradiation profile:  Beam parameters:  440 GeV/c proton beam,  Gaussian shape, σ= 0.3mm  Total 4.9e13 proton, in 20 pulse, over a half day  2.45e12 proton/pulse, pulse length = 1 second,  30 minutes between pulses  Cooling times:  1day, 1 week, 1 month, 3 months, 6 months, 1 year, 2 years 23 Activation Study 3 HiRadMat Technical Board Review15/10/2014

Residual dose rate After 3 months cooldown, averaged in a 1 mm thick plane around the beam line 24 Activation Study 3 HiRadMat Technical Board Review15/10/2014

Residual dose rate After 3 months cool down:  Maximum value in the X-Y plane for each Z coordinate  Maximum value: 9.90 μSv/h in the glassy carbon wall after the Be slugs.  Highest value in Be slug: 7.71 μSv/h  Highest value in Al: 3.10 μSv/h around the exit window 25 Activation Study 3 HiRadMat Technical Board Review15/10/2014

Residual dose rate  After 1 day the dose from the activation of the containment is the prominent one.  Between 1 week and 6 months the radiation from the Be dominates.  After 1 year the containment again is the bigger contributor. 26 Activation Study 3 HiRadMat Technical Board Review15/10/2014

27 Activation Study 3 HiRadMat Technical Board Review15/10/2014

28 Activation Study 2 HiRadMat Technical Board Review15/10/2014

29  HRMT24 will investigate failure modes of Beryllium discs induced by high intensity beam conditions to aid the development of beryllium windows and targets  A design of the experimental apparatus is in process which will include:  Samples held in containment boxes sealed by dual graphite/glassy carbon beam windows.  Outer chamber with internal volume actively pumped during operation with outlet to HEPA filter.  Instrumentation including LDV, strain gauges, PT100s, two camera systems.  A shutter system to seal outer chamber following experiment or in case of emergency.  Initial analyses indicates 3 months provides ample time for residual activity levels to fall to a safe level for containment box extraction. Summary HiRadMat Technical Board Review15/10/2014