Vienna, 17 September 2008 CRYRING as LSR at FLAIR Håkan Danared Manne Siegbahn Laboratory Håkan Danared Manne Siegbahn Laboratory

FLAIR Facility for Low-energy Antiproton and Ion Research FLAIR Facility for Low-energy Antiproton and Ion Research Planning for FLAIR started in 2003, after the original design of FAIR as described in the CDR of 2003 was made Letter of Intent submitted to GSI in early 2004 Technical Proposal submitted in its first version in early 2005 PAC evaluation of all proposed FAIR experiments, including FLAIR, in spring 2005* Approved by STI as part of Core Experi- mental Facility in summer 2005 Definition of FAIR Phase A includes FLAIR in autumn 2007 Next step: establishing FAIR GmbH and signing of Convention by member states *) “FLAIR will be the world's unique facility combining low energy antiprotons and exotic ions. It will provide forefront research opportunities on challenging physics in the 2010's. The committee evaluates its extraordinary significance and recommends it to become an integral part of the FAIR facilities.” A “next-generation” facility for low-energy antiprotons with ∼1×10 7 pbar/s, decelerated and phase-space cooled down to 20 keV in three successive deceleration rings

Antiproton Production at FAIR SIS 100 4× GeV, 0.1 Hz pbar Target 2× GeV, 0.1 Hz Proton Linac 5× MeV, 5 Hz SIS 18 5× GeV, 5 Hz CR/RESR 7× GeV NESR ∼1× MeV, ∼0,05 Hz Data on pbar production according to FAIR BTR LSR ∼1× keV, ∼0,05 Hz USR, HITRAP See Welsch, Quint

FLAIR Experiments F1HCI, E ion < 130 MeV/u from NESR and LSR Interaction of low-energy HCI with composite and solid targets A. Bräuning-Demian, GSI Darmstadt F2HCI, E = 4 MeV/u; pbar, E = 4 MeV from NESR and LSR HITRAP W. Quint, GSI Darmstadt F3HCI, E < 15 MeV/u; pbar, E = 30 MeV from NESR Low-energy Storage Ring (LSR) H. Danared, MSL, Stockholm F4pbar, E < 300 keV from LSR Ultra-low energy Storage Ring (USR) Carsten Welsch, Manfred Grieser, MPI, Heidelberg F5pbar, E < 20 keV from USR Antihydrogen experiment J. Walz, MPQ Garching F6pbar, E < 20 keV to rest from USR and HITRAP Antihydrogen experiment E. Widmann, SMI, Vienna F7pbar, 300 keV < E < 30 MeV from LSR Nuclear and particle physics with antiprotons D. Grzonka, FZ Jülich F8pbar, 30 MeV < E < 300 MeV from NESR Antiproton interaction with biological probes M. Holzscheiter, Pbar Labs, USA F9pbar, E < 20 keV from USR / HITRAP and RIBs from SFRS Cusp trap for anti-H production, pbar atom formation, pbar radioactive nuclei M. Wada, Y. Yamazaki, Tokyo University F10HCI and pbar in the keV energy range from HITRAP Heavy-ion experiments, ion surface interaction, collision dynamics, pbar atom X-ray spectroscopy W. Quint, GSI Darmstadt F1 F2 F10 F3 F4 F5 F6 F7 F8 F9

CRYRING CRYRING is a small synchrotron and storage ring with electron cooling, built for research in atomic, molecular and nuclear physics Design and construction of the storage ring started in 1986 The first stored beam was in January 1991 Start of experimental programme in June The Swedish Research Council decides to stop funding operation in June MSL will get a contract with the Research Council in autumn of 2008 for the transfer of CRYRING to FAIR as a Swedish in-kind contribution Circumference: m Superperiodicity:6 Maximum rigidity:1.44 Tm Injection energy:300 keV/u using RFQ Maximum energy:96 (q/A) 2 MeV/u Acceptance hor.:200  mm mrad Acceptance vert.:100  mm mrad Acceptance long.:1.5 % Horizontal tune:2.44 Vertical tune:2.42 Horizontal chromaticity:-1.3 Vertical chromaticity:-3.2 Transition gamma:2.23

CRYRING ⇨LSR CRYRING is very well suited to its new role as antiproton (and ion) decelerator. It has the right energy interval, fast ramping, efficient electron cooling, good vacuum, it has been running with both positive and negative ions, both for acceleration and deceleration,... Injection of antiprotons from NESR to LSR will be made at a fixed energy 30 MeV, and ions will be injected at the same magnetic rigidity. Extraction of antiprotons will take place at 300 keV, equal to the injection energy of the USR. Also extraction at other energies e.g, 4.2 MeV for HITRPAP, will be possible. Both fast (single-turn) and slow (resonant, multiturn) extraction will be implemented. The main modifications to CRYRING are thus new injection and extraction systems. CRYRING has a low-energy injector for singly charged ions, such as p and H –, which also will be transferred to FLAIR for commissioning of LSR, beamlines, etc. in the FLAIR hall without use of expensive antiprotons. Installation of an ECR source for commissioning and tests with highly charged ions is being considered.

Ions Stored in CRYRING and in most cases used for physics experiments Ions Stored in CRYRING and in most cases used for physics experiments Singly charged positive atomic ions: H +, D +, 3 He +, 4 He +, 7 Li +, 9 Be +, 11 B +, 12 C +, 14 N +, 16 O +, 40 Ar +, 40 Ca +, 45 Sc +, 48 Ti +, 56 Fe +, 83 Kr +, 84 Kr +, 86 Kr +, 88 Sr +, 129 Xe +, 131 Xe +, 132 Xe +, 138 Ba +, 139 La +, 142 Nd +, 151 Eu +, 197 Au +, 208 Pb + Multiply charged positive atomic ions: 4 He 2+, 11 B 2+, 12 C 2+, 12 C 3+, 12 C 4+, 12 C 6+, 14 N 2+, 14 N 3+, 14 N 4+, 14 N 7+, 16 O 2+, 16 O 3+, 16 O 4+, 16 O 5+, 16 O 8+, 19 F 6+, 19 F 9+, 20 Ne 2+, 20 Ne 5+, 20 Ne 6+, 20 Ne 7+, 20 Ne 10+, 28 Si 3+, 28 Si 11+, 28 Si 14+, 32 S 5+, 36 Ar 9+, 36 Ar 10+, 36 Ar 12+, 36 Ar 13+, 40 Ar 9+, 40 Ar 11+, 40 Ar 13+, 40 Ar 15+, 48 Ti 11+, 58 Ni 17+, 58 Ni 18+, 84 Kr 33+, 126 Xe 36+, 129 Xe 36+, 129 Xe 37+, 136 Xe 39+, 136 Xe 44+, 207 Pb 53+, 208 Pb 53+, 208 Pb 54+, 208 Pb 55+ Singly charged postive molecular ions: H 2 +, HD +, H 3 +, D 2 +, H 2 D +, 3 HeH +, 3 HeD +, 4 HeH +, D 3 +, He 2 +, LiH 2 +, D 5 +, BH 2 +, CH 2 +, NH 2 +, OH +, CH 5 +, NH 4 +, H 2 O +, H 3 O +, HF +, ND 3 H +, CD 5 +, ND 4 +, D 3 O +, C 2 H +, CN +, C 2 H 2 +, HCN +, C 2 H 3 +, HCNH +, C 2 H 4 +, CO +, N 2 +, 13 CO +, N 2 H +, C 2 H 5 +, NO +, D 13 CO +, CH 3 O +, CF +, O 2 +, CH 3 NH 3 +, CH 3 OH +, CH 3 OH 2 +, H 2 S +, CD 3 O +, PD 2 +, N 2 H 7 +, D 2 32 S +, CD 3 OH 2 +, CD 3 OD +, H 5 O 2 +, D 2 34 S +, D 3 32 S +, CD 3 OD 2 +, 13 CD 3 OD 2 +, D 3 34 S +, C 3 H 4 +, D 5 O 2 +, CH 3 CNH +, C 3 D 3 +, N 2 D 7 +, N 3 +, DCOOD 2 +, C 3 H 7 +, NaD 2 O +, CO 2 +, HCS +, C 2 H 5 O +, DN 2 O +, C 2 H 5 OH +, CO 2 D +, CD 3 CDO +, NO + ·H 2 O, O 3 +, CD 3 OCD 2 +, C 3 D 7 +, CF 2 +, NO + ·D 2 O, DC 3 N +, CD 3 OCD 3 +, N 3 H 10 +, DC 3 ND +, CD 3 ODCD 3 +, H 7 O 3 +, COS +, N 2 O 2 +, CH 3 OCOH 2 +, D 7 O 3 +, N 3 D 10 +, C 4 D 9 +, S 18 O 2 +, ArN 2 +, H 9 O 4 +, CD 3 COHNHCH 3 +, CD 3 CONHDCH 3 +, C 6 D 6 +, PO 37 Cl +, H 11 O 5 +, C 2 S 2 H 6 +, C 2 S 2 H 7 +, H 13 O 6 +, PO 35 Cl 2 + Multiply charged positive molecular ions: N 2 2+ Negative atomic ions: H –, Li –, F –, SI –, S –, Cl –, Se –, Te – Negative molecular ions: CN –, C 4 –, Si 2 –, Cl 2 – Range of energies per nucleon: 38 eV/u – 92 MeV/u Range of total energies: 5 keV – 1.4 GeV

Intensity Limit in LSR/CRYRING Intensity in CRYRING is limited by space-charge, causing a tune shift. Assuming a certain permissible tune shift, the maximum intensity for (anti)protons can be plotted as a function of beam energy and emittance. In the case of a bunched beam, the maximum particle number is reduced by the bunching factor. Ref: H. Danared et al., Proc COOL07, Bad Kreuznach 2007, p. 234, Maximum number of protons stored in CRYRING at 300 keV is 4.7×10 9, at a beam emittance of approx. 15π mm mrad horisontally and 5π mm mrad vertically, indicating a tune shift of approx A similar maximum particle number of 4.1×10 9 has been obtained with alpha particles, which have the same r 0. These intensities were obtained by stacking, using continuous injections while electron-cooling. The highest-intensity beams were quite unstable. Maximum intensity at deceleration is smaller due to higher demands on stability and because of bunching – see following slides.

Electron Cooling of H − Ions Electron cooling is in the first approximation based on the Coulomb interaction between ions and electrons, and cooling rates should thus be sensitive only to the ion charge squared. However, the magnetic field in the cooler can make cooling rates depend on the sign of the ion charge. Such effects were seen in measurements in Novosibirsk where a stronger drag force was observed for negative particles. Transverse cooling of H − ions at 3 MeV (similar to expected cooling energy at FLAIR), initial emittance 5π mm mrad, which is more than expected at FLAIR. The beam reaches a cold equilibrium in ∼1.5 s. The figure shows the vertical beam profiles, as measured with a residual-gas-ionization beam- profile monitor. Cooling time for H − compared to previous measure- ments at CRYRING with positive ions. Electron density normalized to 1.7×10 13 m −3. Cooling times for highly charged ions are scaled with q 1.7 /A. The points are shifted horizontally so that the time for reaching the cold equilibrium is similar for all ion species. Conclusion 1: We do not observe a significant difference between cooling of positive and negative particles. Conclusion 2: Cooling times are sufficiently short such that throughput of antiprotons at FLAIR will not be limited by cooling in the LSR.

Deceleration of Protons To verify the performance of CRYRING as a deceleration ring, protons have been decelerated through the same range of energies as at FLAIR, from 30 MeV to 300 keV.Injection of protons in CRYRING is always at 300 keV, so deceleration is made after acceleration to 30 MeV. Transmission 1 Start acceleration 93 % Cooling, acceleration ramp 100 % Start deceleration 99 % Deceleration ramp 92 % Complete cycle 0.95×0.97×0.84=85 % Deceleration only 0.99×0.92=91 % Transmission 2 Start acceleration 95 % Cooling, acceleration ramp 100 % Start deceleration 97 % Deceleration ramp 84 % Complete cycle 0.95×0.97×0.84=77 % Deceleration only 0.97×0.84=81 % Conclusion: CRYRING is already able to decelerate >1×10 8 (anti)protons with <10 % losses in <2 s, exceeding the intensity forseen from NESR and the commissioning target set by FAIR.

Simulations of Slow Extraction

Current Status and Plans Nov 07FAIR start event, Sweden decides to contribute 10 M€ to the construction of FAIR, including 2 M€ for CRYRING in-kind Mar 08FLAIR decides to accept CRYRING as the LSR Jun 08Swedish Research Council promises 30 MSEK to MSL for the transfer of the ring to FAIR Sept 08Start of detailed design of new injection and extraction Modifications made to CRYRING and commissioned at MSL Dec 10CRYRING disassembled and put in boxes for storage 2014?Reassembly in the FLAIR hall