Towards (anti)hydrogen production Am elia Leite SPP/Irfu, Cea - PowerPoint PPT Presentation

Towards (anti)hydrogen production Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Outline ◮ Motivation for GBAR ◮ GBAR in 3 steps ◮ How do we produce (anti)hydrogen? ◮ Positron production and accumulation ◮ Positronium ◮ Proton source ◮ Conclusion Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 2

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Motivation Weak Equivalence Principle is a cornerstone of relativity ↓ Never been tested with Antimatter ↓ Absence of primordial antimatter in the observable Universe → Different behaviour of antimatter under gravity? ⇓ GBAR : G ravitational B ehaviour of A ntihydrogen at R est ↓ ¯ g measurement Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 3

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR : G ravitational B ehaviour of A ntihydrogen at R est Measure the acceleration of ¯ H in free fall gravitational mass of H inertial mass of H free fall time free fall height gravitational acceleration initial vertical velocity Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 4

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR : G ravitational B ehaviour of A ntihydrogen at R est Measure the acceleration of ¯ H in free fall gravitational mass of H inertial mass of H free fall time free fall height gravitational acceleration initial vertical velocity Original idea: H + ions to achieve µ K temperature (0.1 m/s) by sym- Use ¯ pathetic cooling → e + photodetachment → ¯ H free fall Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 5

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR in 3 steps Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 6

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR in 3 steps Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 7

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR in 3 steps Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 8

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR @ Saclay slow e+ beam line 3x10 6 e+/s e- linac e-/e+ magnetic W target+ 4.3 MeV moderator separator Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 9

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Cross section measurements 1. Hydrogen and negative hydrogen ion production p + Ps → H + e + @Cea e - e + Ps H + Ps → H − + e + @Cern Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 10

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Cross section measurements 1. Hydrogen and negative hydrogen ion production p + Ps → H + e + @Cea e - e + Ps H + Ps → H − + e + @Cern 2. Antihydrogen and antihydrogen ion production e + H + e − @Cern p + Ps → ¯ ¯ p H + + e − @Cern H + Ps → ¯ ¯ + H e + Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 11

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Positron accumulation Buffer gas trap Charged particles can be stored in a Penning trap ad eter- num (if your trap is good enough!) Yet the e + need to loose enough energy → use a buffer gas 8 − 11 eV + N 2 → e + + N ∗ for inelastic collisions: e + 2 Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 12

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Positron accumulation Buffer gas trap Charged particles can be stored in a Penning trap ad eter- num (if your trap is good enough!) Yet the e + need to loose enough energy → use a buffer gas 8 − 11 eV + N 2 → e + + N ∗ for inelastic collisions: e + 2 Penning-Malmberg trap Store e + bunches and form a plasma with 10 10 e + Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 13

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Buffer gas trap Two stage trap with a third stage accumulator Efficiency ∼ 20% to 30% Cooling with CO 2 or SF 6 To Penning 50 eV e+ -Malmberg trap Trapping with N 2 pumping Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 14

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Buffer gas trap We are slowly building the trap from scratch... Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 15

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Buffer gas trap Now it looks better but it’s not ready yet! Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 16

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Penning-Malmberg trap Superconducting magnet: 5T → radial confinement Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 17

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Penning-Malmberg trap 27 annular electrodes: electrostatic field → longitudinal confinement Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 18

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Penning-Malmberg trap Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 19

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Accumulation technique e + injection → e + confinement + stacking → e + ejection Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 20

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Accumulation technique e + injection → e + confinement + stacking → e + ejection Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 21

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Positronium production Mesoporous film, SiO 2 Para-positronium, τ =125ps e + Ortho-positronium, τ =142ns Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 22

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Proton source Quadrupole Faraday cup Dri� tube for TOF Steering & focussing Proton gun Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 23

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Reaction scheme Electrostatic quadrupole Camera Faraday cup H Microchannel plate detector p & Phosphor screen H - Mesoporous film, SiO 2 Si 3 N 4 membrane e + Ps Camera p Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 24

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Conclusion ◮ Setup assembly in progress ◮ Commission during summer ◮ Stay tuned for hydrogen production next fall! Thank you! Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 25

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Questions? Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 26

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Extra Slides Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 27

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion GBAR vs AEGIS GOAL : ∆g g ≤ 1 % GBAR: cooled ¯ H + → slow ¯ H L = 0.1 m and v ¯ H = 0.5 m / s ⇒ 20 cm ( T ¯ H ∼ 10 µK ∼ 7 neV ) AEGIS: ¯ H beam L = 1 m and v ¯ H = 500 m / s ⇒ 20 µ m ( T ¯ H ∼ 100 mK ∼ 7 µeV ) Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 28

Motivation GBAR in 3 steps Cross section measurements Positron accumulation Proton source Conclusion Equivalence principle “The trajectory of a point mass in a gravitational field depends only on its initial position and velocity, and is independent of its composition and structure.” Am´ elia Leite SPP/Irfu, Cea Saclay PHENIICS Doctoral School Days 29