A Next-generation Low-energy Antiproton Facility

Transcription

1 A Next-generation Low-energy Antiproton Facility E. Widmann, University of Tokyo Chairman, FLAIR steering committee Nuclear J-PARC Workshop NP04, Tokai, August 2 4, 2004 University of Tokyo

2 Antiproton production and current antiproton machines University of Tokyo

3 Antiproton CERN p + p p+ p+ p + p Threshold 6 m p (5.6 GeV) PS: 26 GeV J-PARC Antiprotons of 3.6 GeV/c Low-energy beam Accumulation Deceleration Cooling (stochastic & electron) : AAC 3 separate rings (AC, AA, LEAR) Since 2000 All-in-one machine: AD AD E. Widmann, Next-generation Low-energy Antiproton Facility p. 3 NP04 Tokai

4 Antiproton Decelerator (AD) at CERN Antiproton production! # % A JK F / A 8? Scale F > = H E A? JE * K? D H J= JE 5 J? D = I JE?? E C % & I 0 5 AD PROJECT 10m. 5 J? D = I JE?? E C $ $ I 6 K A K F ATRAP ASACUSA DEM A T H E AN * = I E? ),, A? A A H = JE + O? A - A? JH? E C " I - A? JH? E C # # I 4 A > K? D E C. = I J- N JH =? JE )? JK =, K H = JE, A I EC, K H = JE!! #!! # " # % # & & # $ JE A I A? D $! * A = > K? D B A? A A H = JE A > K? D B H? E C & &. 2 " 4 A L Started operation 2000 Antiproton capture, deceleration, cooling 100 MeV/c (5.3 MeV) Pulsed extraction 2-4 x 10^7 antiprotons per pulse of 100 ns length 1 pulse / 85 seconds Antiprotonic atom formation and spectroscopy incl. Antihydrogen (ATRAP, ATHENA) Operation until 2010 in CERN medium range plan Evaluation in Sep E. Widmann, Next-generation Low-energy Antiproton Facility p. 4 NP04 Tokai

5 Physics at the AD: precision spectroscopy of antiprotonic atoms & antihydrogen for tests of CPT symmetry University of Tokyo

6 Verifications of CPT symmetry Tests of particle/antiparticle symmetry (PDG) Kostelecky: energy scale < GeV < GeV < GeV < GeV Inconsistent definition of figure of merit: comparison difficult Pattern of CPT violation unknown (P: weak interaction, CP: mesons) E. Widmann, Next-generation Low-energy Antiproton Facility p. 6 NP04 Tokai

7 phe + Atomcule - a Naturally Occurring Trap for Antiprotons Pair of metastable and short-lived states Laser deexcitation -> annihilation on demand Laser spectroscopy method of forced annihilation ASACUSA collaboration τ ~ µs τ 10 ns E. Widmann, Next-generation Low-energy Antiproton Facility p. 7 NP04 Tokai

8 Laser Spectroscopy at Ultra-low Density: Radio Frequency Quadrupole Decelerator: kev RFQD: 5.3 MeV -> kev (eff. > 25%) Differential pumping + ultra-thin beam window (~ 1 µm Kapton) high efficiency of stopping antiprotons at ultra-low densities (p < 1 mbar, T~20 K) E. Widmann, Next-generation Low-energy Antiproton Facility p. 8 NP04 Tokai

9 Progress in atomcule spectroscopy Laser spectroscopy: Ry ~ MQ 2 LEAR ω c ~ Q/M (10 10 ) Comparison to 3-body QED calculations Separate CPT test of proton/antiproton charge and mass Cooled beams at < 100 kev E. Widmann, Next-generation Low-energy Antiproton Facility p. 9 NP04 Tokai

10 Precision Spectroscopy of p Atoms AD 5.3 MeV pbar 1 π mm mrad E/E~10^-4 Pbar cloud: 1 cm^3 CPT test 60 ppb AD + RFQD 100 kev 100 π 5% 1000 cm^3 10 ppb FLAIR 20 kev 1 π 10^-4 1 mm^3 << 1 ppb E. Widmann, Next-generation Low-energy Antiproton Facility p. 10 NP04 Tokai

11 First Cold Antihydrogen AD Nested Penning traps Capture energy: few kev ATHENA Nature 419 (2002) 456 ATRAP PRL 89 (2002) No useful Hbar produced (ground-state, < 1 K temperature for trapping) Ultimate precision: neutral atom trap and laser cooling to milli-kelvin temperature E. Widmann, Next-generation Low-energy Antiproton Facility p. 12 NP04 Tokai

12 H Ground-state Hyperfine Structure atoms evaporate No trapping needed!! atomic beam for focussing and spin selection spin-flip by microwave radiation low-background high-efficiency detection of antihydrogen through annihilation achievable resolution better 10 6 for T 100 K > 100 H/s in 1S state needed ultimate precision: atomic fountain of H -> FLAIR ASACUSA proposal for AD E.W. et al. CERN-SPSC E. Widmann, Next-generation Low-energy Antiproton Facility p. 13 NP04 Tokai

13 Features of a Next-generation Low-energy Antiproton Facility Feature Higher intensity Solution Accumulation scheme Fast and slow extraction Cooled beams down to < 500 kev Availability of pbar and RI Coincidence experiments (nuclear physics) Storage rings Darmstadt E. Widmann, Next-generation Low-energy Antiproton Facility p. 14 NP04 Tokai

14 Facility for Antiproton and Ion Research Darmstadt Gain Factors Primary beam intensity: Factor Secondary beam intensities for radioactive nuclei: up to factor 10,000 Beam energy: Factor 20 SIS 100/300 Special Properties SIS UNILAC FRS HESR ESR CR 100 m NESR E. Widmann, Next-generation Low-energy Antiproton Facility p. 15 FL AIR Super FRS Intense, fast cooled energetic beams of exotic nuclei Cooled antiproton beams up to 15 GeV Internal targets for high-luminosity in-ring experiments Parallel Operation New Technologies Fast cycling superconducting magnets Electron cooling at high ion intensities and energies Fast stochastic cooling NP04 Tokai

15 Antiproton production at FAIR Central part of planned facility HESR: meson spectroscopy in charmonium region Production with 30 GeV p from SIS pbar / 4 sec Momentum 3.7 GeV/c Capture and cooling in CR Accumulation in RESR Re-injection into SIS100 Acceleration for HESR Deceleration in NESR Min. energy 30 MeV E. Widmann, Next-generation Low-energy Antiproton Facility p. 16 NP04 Tokai

16 FLAIR A Facility for Low-energy Antiproton and Ion FAIR NESR Pbar & Ions MeV LSR Standard ring Min. 300 kev USR Electrostatic Min. 20 kev HITRAP pbar and ions Stopped & 5 kev www-linux.gsi.de/~flair CRYRING Challenging, new MPI-K HD with cave AP part of CDR Factor 100 more pbar trapped or stopped in gas targets than now E. Widmann, Next-generation Low-energy Antiproton Facility p. 17 NP04 Tokai

17 CRYRING and FLAIR Storage ring at Manne Siegbahn Lab, Stockholm Is to stop operation within ~2 years Perfect fit for FLAIR LSR: Energy range, electron cooling, internal target, lowenergy injection from ion source for commissioning E. Widmann, Next-generation Low-energy Antiproton Facility p. 18 NP04 Tokai

18 FLAIR Physics Topics with Antiprotons Spectroscopy for tests of CPT and QED Antiprotonic atoms (pbar-he, pbar-p), antihydrogen Atomic collisions Sub-femtosecond correlated dynamics: ionization, energy loss, antimatter-matter collisions Antiprotons as hadronic probes X-rays of light antiprotonic atoms: lowenergy QCD X-rays of neutron-rich nuclei: nuclear structure (halo) Antineutron interaction Strangeness 2 production Medical applications: tumor therapy Features of FLAIR Low-energy, highbrilliance beams for effective stopping High effective collision rates with USR: fully kinematic measurements Continuous beams: only FLAIR availability of radioactive ions offers synergies High energies, high intensities, slow extraction E. Widmann, Next-generation Low-energy Antiproton Facility p. 19 NP04 Tokai

19 Untra-cold Antihydrogen by Laser Cooling Gravitational acceleration of antimatter Highest precision reachable with neutral antimatter Ultra-cold antihydrogen atoms: sympathetic cooling of H + Hyperfine structure of antihydrogen Microwave resonance of ultra-cold antihydrogen in field-free region Atomic fountain J. Walz and T.W. Hänsch, General Relativity and Gravitation 36 (2004) 561 E. Widmann, Next-generation Low-energy Antiproton Facility p. 20 NP04 Tokai

20 E. Widmann, Next-generation Low-energy Antiproton Facility p. 21 NP04 Tokai

21 E. Widmann, Next-generation Low-energy Antiproton Facility p. 22 NP04 Tokai

22 In-ring Collision Studies Reaction Microscope for fully differential collision measurements Electrostatic storage ring: USR Electron cooler Cavity Internal target (reaction microscope) E. Widmann, Next-generation Low-energy Antiproton Facility p. 23 NP04 Tokai

23 p-ri in Traps for Nuclear Structure Study p annihilates with outermost nucleon R. S. Hayano (Tokyo) Momentum distribution of recoil nuclei Wave function of outermost nucleon Charged pion multiplicity Distinguish annihilation on p and n Halo factors M. Wada, Y. Yamazaki (Tokyo) Nested Penning trap E. Widmann, Next-generation Low-energy Antiproton Facility p. 24 NP04 Tokai

24 Layout of FLAIR Hall New configuration ion source for commissioning, test E. Widmann, Next-generation Low-energy Antiproton Facility p. 25 NP04 Tokai

25 FLAIR Community Austria (Vienna IMEP, TU) Canada (York) Denmark (Aarhus U, ISA) France (P. & M. Curie, Paris) Germany (GSI, Dresden, Frankfurt, Freiburg, München, Giessen, Heidelberg, Jülich, Mainz, Tübingen) Hungary (Budapest, Debrezen U, ATOMKI) Italy (Bologna, Firenze, Genova, Torino) E.W. chairman steering committee Japan (Tokyo, Saitama (RIKEN)) Netherlands (Amsterdam U, FOM) Poland (Warsaw U, Soltan Inst.) Russia (Moscow, St. Petersburg) Sweden (Stockholm U, Manne Siegbahn Laboratory) United Kingdom (Swansea) USA (Albuquerque, Harvard, pbar Medical, Texas A&M) 47 institutions, 14 countries E. Widmann, Next-generation Low-energy Antiproton Facility p. 26 NP04 Tokai

26 Summary and status of FLAIR Cooled antiprotons at 20 kev will revolutionize lowenergy antiproton physics DC beams enable nuclear and particle physics type experiments (not possible at AD) Availability of radioactive ion beams (RIB) offers new synergies Status of FLAIR LoI was approved in March 2004 Technical proposal due January 15, 2005 final approval follows (hopefully), 1 st beam 2012 (?) Funding still needs to be secured (total MEuro) BUT: FAIR itself not yet finally approved Expectation: middle of 2005 Important: 25% contribution from outside Germany E. Widmann, Next-generation Low-energy Antiproton Facility p. 27 NP04 Tokai

27 FLAIR J-PARC Picture from L26 Pulsed Proton beam facility for J-PARC E. Widmann, Next-generation Low-energy Antiproton Facility p. 28 NP04 Tokai