Design of the LBNF beamline Tristan Davenne for
Design of the LBNF beamline Tristan Davenne for the DUNE collaboration Rutherford Appleton Laboratory Acknowledgements Jim Hylen, Alberto Marchionni, Patrick Hurh, Cory Crowley, Rowan Zaki, Laura Fields, Bob Zwaska and all our Fermilab colleagues The 19 th International Workshop on Neutrinos from Accelerators 25 -30 September 2017 Uppsala University Main Building
South Dakota
Drivers for LBNF beamline design •
Two different horn configurations under consideration
Courtesy of Rowan Zaki
• Horn must endure stress due to combined heat load of beam heating and Joule heating • Horn A is the critical horn for operastional stress and expected service life • CFD has shown that the water cooled horn operating temperature is well within acceptable limits (max 40°C) • FEA of the magnetic forces and thermal stresses indicates reasonable safety factors on stress. Courtesy of Cory Crowley
Courtesy of Joseph Angelo
No pressure pulse and vibration associated with sudden water heating Graphite at significantly higher temperature - radiation damage partially annealed. Larger beam spot, lower pulsed power density Target designed to be removable from horn and replaceable Targets and horns may last longer!
RAL target design 2 m+ target must remotely dock into a cooled downstream support Replaceable target concept Improved version of T 2 K CFD and FEA indicate operating temperature, pressure and stress no less favourable than T 2 K Can a 1. 5 m long cantilevered target mitigate risk and provide adequate physics yield?
Target comparison T 2 K (Designed For) T 2 K (Achieved) Nu. MI No. VA LBNF RAL Design Target Material Toyo. Tanso IG-43 POCO ZXF-5 Q Toyo. Tanso IG-43 Beam Energy [Ge. V] 30 30 120 120 Beam Power [k. W] 750 350 400 700 1200 Beam Current [μA] 25 12 3. 3 5. 8 10 3. 3× 1014 1. 8× 1014 4. 0× 1013 4. 9× 1013 7. 5× 1013 Cycle Time [s] 2. 1 2. 5 1. 9 1. 3 1. 2 Beam Sigma [mm] 4. 2 1 1. 3 2. 7 144 67 282 174 118 23 11 53 55 22 Protons per Pulse [] Peak Energy Density in target material [J/g] Peak Proton Fluence on Front Face [μA/cm 2]
Summary 1. Beam focusing: Have complete reference conceptual design for a Nu. MI-like 2 -horn system Completion of conceptual design for a 3 -horn system with longer target, optimized for DUNE detection of νCP violation. This system also allows a 2 -horn staging scenario. Plan to make decision in late 2017 on which course to pursue through preliminary design. 2. Target pile atmosphere and decay pipe cooling: Completed conceptual design for replacing air fill with nitrogen Eliminates production of radioactive 41 Ar Eliminates Ozone and Nitric Acid corrosion 3. Target: Developing Helium cooled target design, alternative to reference water cooled design Beam to DUNE about a decade from now
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