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Cold Antimatter at CERN. The ATHENA, ALPHA and AEGIS Experiments at the AD. Lars V. J ø rgensen – Swansea Univ. / CERN. Outline. What is antimatter? Why is it interesting? Pure research Practical uses? How do we make it? Making atoms of it Holding on to the atoms.
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Cold Antimatter at CERN The ATHENA, ALPHA and AEGIS Experiments at the AD Lars V. Jørgensen – Swansea Univ. / CERN
Outline • What is antimatter? • Why is it interesting? • Pure research • Practical uses? • How do we make it? • Making atoms of it • Holding on to the atoms Lars V. Jørgensen – CERN - June 23, 2011
Antimatter – What is it? An equation from Quantum Mechanics 2 X = K Dirac’s equation: (1928) • Has 2 solutions • One positive • One negative Positive solution fits normal matter i.e. electron, protons, etc. What is the negative solution ??? Lars V. Jørgensen – CERN - June 23, 2011
Antimatter – What is it? Anti-particles: • Opposite charge • Same mass • Exactly cancels out it’s normal matter ‘partner’ Lars V. Jørgensen – CERN - June 23, 2011
The first antimatter is discovered. Carl Anderson at Cal Tech observes the first positron from cosmic ray showers in 1932 Quick Nobel Prizes: Dirac 1933 Anderson 1936 Lars V. Jørgensen – CERN - June 23, 2011
Discovering more anti-particles 2 E = m c • Mass is energy (nuclear power) • But also: Energy is mass • High Energy Physics !! Pair Creation: With high enough energy a pair of matter-antimatter Particles can be created Antiproton – 1955 Antineutron – 1957 Antideuteron– 1965 Antihelium-3 – 2011! Surrounding Edward Lofgren (center), head of the Bevatron, are discoverers of the antiproton, (left to right) E.Segre, C.Wiegand, O. Chamberlain and T.Ypsilantis. Lars V. Jørgensen – CERN - June 23, 2011
Anti – atoms? • In 1995 9 atoms of antihydrogen was made at CERN’s LEAR machine • All these atoms were at very high energy • To study antihydrogen we need it at much lower energies CERN’s LEAR Machine CERN built the AD (Antiproton Decelerator) to achieve this! It started operation in 2000 Lars V. Jørgensen – CERN - June 23, 2011
Why is antimatter interesting? Why are we here? • If the Big Bang was Pair Creation there should be equal amounts of matter and antimatter in the universe • We know from measurements that there is almost no antimatter in the universe • Why is this ?? Antimatter at the center of the Milky Way Lars V. Jørgensen – CERN - June 23, 2011
Fundamental studies of anti-hydrogen CPT tests “Hänsch Plot” • Spectroscopy – checking if the energy-levels are the same in hydrogen and antihydrogen • This tests some very fundamental theories in physics – the standard model and the CPT Theorem (C=charge, P=parity and T=time) Lars V. Jørgensen – CERN - June 23, 2011
What about Gravity? Does antimatter fall down ?? Gravity is a very, very weak force compared to the other forces e.g. Electro-magnetism This makes an experiment VERY difficult - but neutral atoms are necesary Theory is not so clear ! ... But most people expect it to behave like matter New experiment at the AD now under construction: AEGIS - Antimatter Experiment: Gravity, Interferometry, Spectroscopy Lars V. Jørgensen – CERN - June 23, 2011
Are there practical things where antimatter might be useful ? • PET scanners (Positron Emission Tomography) • Treating cancer with antiprotons (The ACE experiment) Lars V. Jørgensen – CERN - June 23, 2011
Passing into the antiworld? France Switzerland AD PS LINAC2 Lars V. Jørgensen – CERN - June 23, 2011
How do we make anti-matter ? Lars V. Jørgensen – CERN - June 23, 2011
_ + p e Na22 source Making antihydrogen • We take antiprotons and slow them down MUCH, MUCH more • We collect a lot of positrons • We get them together • They make antihydrogen and fly to the wall • We detect them Lars V. Jørgensen – CERN - June 23, 2011
Detecting that we have made antihydrogen • We build a detector that can measure the annihilation of an antiproton and a positron at the same time and at the same place Lars V. Jørgensen – CERN - June 23, 2011
Ioffe-Pritchard Geometry quadrupole winding mirror coils Next step: Trapping antihydrogen Antihydrogen Trapped! Nature, 17 Nov. 2010 More antihydrogen trapped for 1000 seconds! Nature Physics, 5 June 2011 • Antihydrogen or hydrogen are tiny magnets – kinda! • We use this to try to trap them • Difficult as charged antiprotons and positrons must also survive • Very weak trapping field: 1 T ~ max. 0.7 K How ??? Lars V. Jørgensen – CERN - June 23, 2011
How ALPHA did it! Lars V. Jørgensen – CERN - June 23, 2011
Ready for spectroscopy? • Antihydrogen trapped • Antihydrogen in ground state • Survives for a long time • Not very many anti-atoms at any given time (max 1 so far) • No laser access yet • Microwaves !! Lars V. Jørgensen – CERN - June 23, 2011
The AEGIS experiment Measuring g for antihydrogen to about 1% • Under construction • Should take first • beam at end of 2011 • Results? 2014-2015? Does antimatter fall up ?? Lars V. Jørgensen – CERN - June 23, 2011
See the real thing!!! Let’s go down to the AD and have a look!!! Lars V. Jørgensen – CERN - June 23, 2011
The ATHENA Collaboration 35 physicists Lars V. Jørgensen – CERN - June 23, 2011
The ALPHA Collaboration The ALPHA Collaboration Lars V. Jørgensen – CERN - June 23, 2011
LAPP, Annecy, France G. Drobychev, D. Sillou Queen’s U Belfast, UK G. Gribakin, H.R.J.Walters INFN Firenze, Italy G.Ferrari, M. Prevedelli, G. Tino CERN M. Doser, A. Duradev, T. Eisel, F. Haug, T. Niinikoski, D. Perini , J. Bremer INFN Genova, Italy C. Carraro, V. Lagomarsino, G. Manuzio, G. Testera, R. Vaccarone, S. Zavatarelli MPI-K Heidelberg C. Canali, R. Heyne, A. Fischer, A. Kellerbauer, C. Morhard, U. Warring Kirchoff Inst. Of Phys., Heidelberg, Germany M. Oberthaler INFN Milano, Italy I. Boscolo, N. Brambilla, F. Castelli, S. Cialdi, L. Formaro, A. Gervasini, M. Giammarchi, F. Leveraro, A. Vairo INR Moscow, Russia A.S. Belov, S. Gninenko, V. A. Matveev, A. V. Turbabin ITEP Moscow, Russia W. M. Byakov, S. V. Stepanov , D.S. Zvezhinskij Université Claude Bernard, Lyon, France P.Nedelec New York Univ. USA H.H. Stroke University of Oslo and University of Bergen, Norway O. Rohne, S. Stapnes, H. Sandacker INFN Pavia-Brescia, Italy G.Bonomi, A. Fontana, C. Riccardi, A. Rotondi, A. Zenoni Czech Tech. Univ, Prague, Czech Republic V. Petracek, D. Krasnicky IRNE Sofia, Bulgary N. Djurelov INFN Padova-Trento, Italy R.S. Brusa, D. Fabris, M. Lunardon, S. Mariazzi, S. Moretto, G. Nebbia, S. Pesente, G. Viesti ETH Zurich, Switzerland S.D. Hogan, F. Merkt Qatar University I. Y. Al-Qaradawi, L. V. Jørgensen PolitecnicoMilano, Italy G. Consolati, A. Dupasquier, R. Ferragut, P. Folegati, F. Quasso La. Aime’Cotton, Orsay, France L. Cabaret, D. Comparat Lars V. Jørgensen – CERN - June 23, 2011