1. Towards the production of an anti-hydrogen beam Simon Van Gorp1, Y.Enomoto1, N.Kuroda2, K.Michishio3, D.J.Murtagh1, S.Ulmer1,, H. Higaki, C.H.Kim2, Y.Nagata1, Y.Kanai1, H.A.Torii2, M.Corradini4, M.Leali4, E.Lodi-Rizzini4, V.Mascagna4, L.Venturelli4, N.Zurlo4, K.Fujii2, M.Otsuka2, K.Tanaka2, H.Imao5,Y.Nagashima3, Y.Matsuda2, B.Juhász6, A.Mohri1 and Y.Yamazaki1,2 1/25 Graduate School of Advanced Sciences of Matter, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan 1 RIKEN Advanced Science Institute, Hirosawa, Wako, Saitama 351-0198, Japan 2 Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan 3 Department of Physics, Tokyo University of Science, Kagurazaka, Shinjuku, Tokyo 162-8601, Japan 4 Dipartimento di Chimica e Fisica per l’Ingegneria e per i Materiali, Universitá di Brescia & Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Brescia, 25133 Brescia, Italy 5 RIKEN Nishina Center for Accelerator Based Science, Hirosawa, Wako, Saitama 351-0198, Japan 6 Stefan Meyer Institute for Subatomic Physics, Austrian Academy of Sciences, 1090 Wien, Austria (ASACUSA-MUSASHI)

2. Why Antihydrogen ? *Antihydrogen is the simplest atom consisting entirely of antimatter. *Hydrogen counterpart is one of the best understood and most precisely measured atoms in physics. *A comparison of antihydrogen and hydrogen offers one of the most sensitive tests of CPT symmetry. If there is some asymmetry we may get aware of it comparing mirrored systems which are fully understood.

3. GOAL High precision spectroscopy of the ground state hyperfine splitting of antihydrogen. HOW? Rabi spectroscopy of a spin-polarized anti-atomic beam.

4. 4/25 Low energy anti-hydrogen atoms (Level diagram) experiments (Hz)  exp / | theory- exp |/ 1S-2S 2,466,061,413,187,103(46)1.7 x 10-141 x 10-11 HFS 1,420,405,751.768(1)6.3 x 10-13(3.5+0.9) x 10-6 (F,M)=(1,-1) (F,M)=(1,0) (F,M)=(1,1) (F,M)=(0,0) experiments performed with hydrogen atoms under field free conditions High Field Seekers Low Field Seekers

5. 3/25 Low energy anti-hydrogen atoms [1] A. Mohri and Y. Yamazaki, Europhys. Lett. 63 (2003) 207. [2] Y. Enomoto et al., Phys.Rev.Lett.105 (2010) 243401. Anti Helmholtz configuration:  HFS-states: de-focused  LFS-states: focused EXTRACTION OF A POLARIZED BEAM

6. RFQD Production target  3.5GeV/c ~5x 107 pbarstochastic cooling  2 GeV/cstochastic cooling  300MeV/cstochastic cooling & e-coolling  100MeV/c(~5MeV) stochastic cooling & e-coolling ~ 107 pbar pulse from AD (~100s cycle)  100keV <5 x 106 pbar with RFQD 9/25 Low energy anti-proton beams (AD to RFQD) ASACUSA extraction line

7. 14/25 How to produce ASACUSA-MUSASHI experimental setup MUSASHI trap – pbar accumulator Positron accumulator CUSP trap Spin flip cavity Sextupole Magnet Detectors We need antihydrogen → has to be synthesized first

8. In Reality Antiprotons from AD RFQD decelerator (200 MHz, 1.1 MW, 0.5 ms) MUSASHI CUSP e+e+

9. Status of the new e+ source e+ source 1.85 Gbq (<100 keV) Cusp trap B = 0.3 T B = 2.7 T 20/25 5 x 10 5 pbar (< 20 eV) B = 2.5 T Ne moderator 2.3 10 6 /s (<3 keV) e+ trap 10 6 /15s (<3 keV)

10. Detection of Antihydrogen Neutral antihydrogen escapes from trap Apply field ionization well → strip positron, catch pbar. Release field ionization well Result after release No peak without positrons Clear indication for production of antihydrogen. Downstream detector: hbar candidate signals detected.

11. 19/25 6 x 10 e+/ 60 shot, ~0.01eV 6 ~ 150eV e+ pulse ~ 150eV pulse Cusp trap H produced ! 201 Direct Injection ( of p) scheme

12. Potential Axial Frequency Scaling Exciting the particles as by a swept rf with a certain stop frequency: Definition of interaction energy How to improve on the F.I. signal ?  A.R.

13. Insert slide AR+Figuur Kuroda-san.

14. Prepare 40 million positrons in the nested Inject directly from MUSASHI trap Apply RF during interaction RF Assisted Direct Injection Produced encouraging results – further evaluation in progress Frequency Scaling in Nested Well

15. 12/25 [11] X.Feng, M.Charlton, M.Holtzscheiter, et al., J. Appl. Phys.79, 8 (1996) Low energy antiproton beam (Tank circuit signal)

16. 13/25 (d) How to produce (Low energy antiproton beam) Tank circuit signal with 3AD shot accumulated in MUSASHI

17. Summary Production of antihydrogen demonstrated. Candidate signals for extracted hbar at downstream detector. Applying Continuous rf incread the Hbar formation rate by ~factor 4. Major step towards first antihydrogen hyperfine spectroscopy.  Analysis of 2012 data is ongoing and results will be presented soon !

18. Thank you for your attention Antiproton trap Positron trap CUSP trap Hbar detector CUSP detectors SMI cavity +sextupole + hodoscope The chief

19. Backup slides

20. Spectroscopy Correction: QED and proton/antiproton structure – level 10-6. Together with high precision proton g-factor measurement: constraints on antiproton structure We aim at 10-6 or better. 1.420 405 751 766 7(9) GHz

21. Proposals to measure more precisely Far Future !

22. 3 x 10 pbar (< 20 eV) 5 18/25 6 x 10 positron (<0.1eV, ne+~108cm-3) 6 CERN PS (3.5GeV/c, 5 x 10 ) AD (5MeV, 10 ) RFQD (100keV, 5 x 10 ) MUSASHI (150eV, 5 x 10 ) 7 6 5 7 27mCi Na (<100keV, ~109 /s) W moderator, N2buffer gas (<3 eV, ~106 /s) Pre-accumulator (130eV, 2 x 105 /30s) 22 positron antiproton (pbar) CUSP trap How to produce Specifications

23. RFQD Production target  3.5GeV/c ~5x 107 pbarstochastic cooling  2 GeV/cstochastic cooling  300MeV/cstochastic cooling & e-coolling  100MeV/c(~5MeV) stochastic cooling & e-coolling ~ 107 pbar pulse from AD (~100s cycle)  100keV <5 x 106 pbar with RFQD 9/25 Low energy anti-proton beams (AD to RFQD) ASACUSA extraction line