Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Concentration and Moderation to Study Muon Catalyzed Fusion in a Deuterium Gas Multiwire Proportional Counter Dr. Larry Burggraf Major Greg Van Dyk Department of Engineering Physics January 7, 2013

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Outline Overview Muon Scatter Muon Moderation Muon Catalyzed Fusion (µCF) Roadmap 2

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Overview Combine modeling and experimental measurements to investigate µCF detection strategy Areas of Research: Muon scatter lens: focus atmospheric muons to increase muons on target Muon moderation: moderate atmospheric muon energies from 1 GeV to approx 50 MeV incident on deuterium detector Muon catalyzed fusion: detection of low energy muons and fusion neutrons, for maximization of fusions in a multi-wire proportional counter 3

Celestial Plane Atmospheric Muons Plastic Coincident 1 NaI Energy Detector Plastic Coincident 2 Time of Flight Energy Information Moderating Material Muon Lens Multiwire Proportional Counter Neutron Detector (24 PMT, EJ-309 Liquid Scintillator) Fusion Products Fusion Products Power Supplies Digital Data Capture NTS Muon Imaging, Moderation and Detection by μCF

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Scatter Phenomenon Use characteristic thickness, t, for a given scattering material to scatter the maximum amount of muons at a certain angle, σ ave (Gaussian distribution width), to a focal point 5 Average scattering angle increases with material thickness

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Scatter Distribution 6 Scattering produces a radial Gaussian distribution As σ ave increases the distribution broadens and the scattering efficiency decreases Scattering can be enhanced if the scattering material is angled towards focal point near vertical Vertical thickness was held constant and optimized for 4° scattering. Inclined from left to right: 2 ° (almost vertical), 90 °(flat).

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Scatter Elements 7 Focal Point y x (0,0) θ1θ1 θ2θ2 Incident Muon t t sin θ 1 θ1θ1 Incident Muon Focal Point y x (0,0) Incident Muon Scattering Material h Inner Surface Outer Surface Assume θ 1 = θ 2 yields the optimal form where the vertical thickness, t, is optimized for θ 1 scattering Functional form: y=he -αx where h is the total height and α varies from 0 (flat) to 1 (vertical)

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Lens: Continuous Design GEANT4 Monte Carlo simulations 1 GeV muons Angle of incidence 0° and 0°-10° Varied α from to 0.9 Varied h from cm Higher α’s yielded higher scattering efficiency at discrete points but lower radial footprint decreases total scattering efficiency Incident angles of 0°-10° favor a lower α Results: ~400% increase in flux on 1 cm 2 target with uniform 0° incident muons, ~50% increase of flux of θ = 0°-10° (cos 2 θ ) incident muons 8

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Lens: Discrete Design Discrete scattering elements shaped to bring normal ( θ=0) muons of energy 1 GeV to same focus on average. Increase scattering efficiency as radial distance increases Larger footprint Larger length of scattering element. Balance with the decreased scattering efficiency inherent as the scattering angle increases Increasing T enhances scattering efficiency GEANT4 simulations within next month 9 Incident Muons T Optimized design to be built and tested: March 2013

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Moderation GEANT4 simulation using 1 GeV muons at 0° incidence (1) Roof with 5.08 cm thick gypsum (2) Steel I-beam with the two horizontal supports each cm thick (3) Second floor with cm thick concrete (4) Steel I-beam with the two horizontal supports each cm thick (5) First floor with cm thick concrete (6) Experimental setup with moderation and detectors— Muon lens to be modeled for final analytical design 10

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Moderation Optimized moderation amount of 130 cm aluminum 1 moderated muon stopping in deuterium gas every 80 minutes without incorporating muon lens Experimental setup to use time of flight data and NaI(Tl) energy detector to optimize the amount of aluminum moderation 11 Optimal moderation experiment complete: April 2013

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Catalyzed Fusion Muon replaces electron in hydrogen isotope (energies less than 10 keV) Distance between two mesic hydrogens closer then two electronic hydrogens ( cm vs cm) Fusion rate 3 orders of magnitude higher Enhanced neutron emission coincident with muon detection Goal: increase fusions per muon by enhanced stripping 12

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Catalyzed Fusion Fusions per muon decreased when fusion products with lower fusion cross sections scavenges the muon ending the µCF cycle Muon can be released through collisions induced by movement in an electric field 13

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Muon Catalyzed Fusion 14 Exterior Wall Anode Cathode Heµ 3 He + µ-µ- D µ µ µCF Multi-wire proportional counter with radial electric field optimal due to little interaction with walls Total radial movement must happen on the order of the muon lifetime, 2.2 µs

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Roadmap Muon Scatter Optimal lens design: February 1, 2013 GEANT4 model: February 15, 2013 Build and test: March 15, 2013 Muon Moderation Test: April 15, 2013 Muon Catalyzed Fusion COMSOL modeling of fields in multiwire proportional counter: February 15, 2013 Muons incorporated into ICEPIC: March 1, 2014 Neutron detector and electronics arrive: March 1, 2013 Pressurized deuterium tank test: June 1, 2013 Multi-wire proportional counter test: August 1,

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Conclusion Overview Muon Scatter Muon Moderation Muon Catalyzed Fusion (µCF) Roadmap 16

Air University: The Intellectual and Leadership Center of the Air Force Aim High…Fly - Fight - Win The AFIT of Today is the Air Force of Tomorrow. Acknowledgments Detector Donations: DTRA Team Site, Kirtland AFB Muon Modeling: Dr Takis Papoulius, Wayne State University Moderation Metal: Wright-Patterson AFB Gun range and AFIT Modeling and Fabrication Shop GEANT Modeling assistance: Dr Abby Bickley and Dr Justin Clinton Detection Electronics Consultation: Maj Benjamin Kowash Research Funding: Dr John Lugisland, AFOSR Questions? 17