1. Mitglied der Helmholtz-Gemeinschaft PAX Status and future plan June 26, 2012 | Alexander Nass

2. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina2 Overview COSY PAX

3. Mitglied der Helmholtz-Gemeinschaft 2006 transport of the HERMES polarized target (Atomic Beam Source (ABS) and Breit-Rabi Polarimeter (BRP)) to Jülich 2006-2009 rebuilding of the ABS and BRP for the use at COSY / AD and design & construction of the target chamber 2008-2012 Construction of an openable storage cell 2009 Installation of the low-β section, commissioning 2010 Installation of the target section at COSY, commissioning 2010-2011 Design, construction and installation of the NEG pump attached to the target chamber 2011 transverse Spin Filter experiment at COSY June 26, 2012SPIN Physics Workshop in Gatchina3 History

4. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina4 The polarized target Production of a polarized atomic beam by an ABS Increase of the target density by means of a storage cell Analysis of target polarization by a BRP and TGA Calibration of the BRP by pp-scattering data ABS BRP The polarized target in LKW-Schleuse

5. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina5 The target chamber Accomodation of the (openable) storage cell and multipurpose detector in a compact design Support of the target holding field coils High pumping speed for target gas Fast shut-off valves to separate and protect COSY vacuum Large flanges to install the complete detector / target cell setup in one operation on a rail system Fixed flow limiters to reduce gas flow into the adjacent sections

6. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina6 The (openable) storage cell Storage cell necessary to increase target gas density up to 10 14 atoms/cm 2 Storage cell walls should suppress recombination and depolarization Openable storage cell to allow the uncooled AD beam to pass Teflon foil walls to detect low energy recoils and suppress recombination and depolarization Fixed cell used in the COSY experiments due to problems with the density in the openable cell

7. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina7 The low-β section Low- β section necessary to increase the acceptance angle to about 6 mrad Small diameter COSY proton beam allows the use of a storage cell and therefore an increased filtering rate

8. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina8 Commissioning of the low-β section and machine development Injection of COSY beam through the fixed cell possible Using frame system acceptance angle measured to be 6.1 mrad Established sufficient long beam lifetimes > 7000s without target gas with 10 10 protons at the desired energy of 49.3 MeV The frame system

9. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina9 The NEG pump High pumping speed in the target chamber necessary to reduce the pressure of the unpolarized H 2 / D 2 gas in the target chamber and adjacent beam line sections Therefore allowing longer beam lifetimes of the COSY proton beam Commercially available NEG cartridges mounted into a bakeable stainless steel box Box is closeable with a jalousie to protect the target cell and detector from the heat when NEG is activated (T=250…400 ° C) Measurements during the spin filter beam time showed pumping speeds of 13000 l/s

10. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina10 Installation at COSY Installation of the target section in COSY in summer 2010 Modular system to remove and install the target quickly One support structure for ABS, BRP and target chamber with NEG pump Rail system for installation of the flange with target cell and future detector

11. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina11 Density of the polarized target gas Intensity measurement of the ABS using an absolute baratron pressure measurement in the center on the storage cell in comparision with a calibrated flux from an unpolarized gas feed system I H2 = (3.0±0.1)·10 16 H 2 /s I H1 = (6.1±0.3)·10 16 H/s

12. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina12 Polarization of the target gas

13. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina13 Transverse Spin Filtering at COSY For more information see talk of D.Oellers Successful spin filter experiment in autumn 2011 8 weeks of data taking All components worked well without major problems at a high performance level Preliminary result for the spin filtering cross section for pp interaction Result is in good agreement with the theoretical predictions and confirms the present understanding of the underlying processes

14. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina14 Future plan September 2012 TRIC test experiment using the PAX-target October 2012 Removal of the PAX-target from COSY ring 2012-2013 Modification and commissioning of the polarized internal target for running with H and D 2012-2013 Design and construction of a multipurpose detector 2013 Installation of the Siberian Snake at COSY PAX site for ANKE experiment(s) with longitudinal beam polarization 2014 Installation of the Siberian Snake at COSY ANKE site and reinstallation of the PAX target with detector 2014-2015 Longitudinal Spin Filter experiment at COSY 2015-2017 TRIC and pd breakup experiments with PAX 20?? Spin filtering with antiprotons at AD/CERN or FAIR

15. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina15 Modifications on the polarized target TRIC and pd breakup need D target Preparation of hardware and software for D Comissioning of target section with D outside COSY p filtering requires H & D in short sequence Prototype of new type RF cavity (dual cavity) was produced and tested with RF- generator bridge Has to be tested with H / D beam Hydrogen Deuterium

16. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina16 The Multipurpose Detector For more information see talk of C.Weidemann Silicon strip detector with 3 layers Readout electronics connected directly in vacuum Liquid cooling system for detectors and electronics Openable cell included in the design Complete setup attached to one flange of the target chamber

17. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina17 Openable Flow Limiters Flow limiters necessary to reduce flow of hydrogen (target) gas into adjacent beam tubes with high β -functions of the (anti)proton beam High gas pressures lead to reduced beam lifetimes of the (anti)proton beam Openable flow limiters necessary since uncooled (anti)proton beam is large (up to 100mm diameter) After beam cooling (diameter <10mm), closing of flow limiters to acceptance limit and injection of target gas

18. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina18 Will allow for flexible use in two locations Fast ramping (< 30 s) with injection of P y Cryogene free system Snake should be available in 2012 / 2013 ANKE PAX ANKE The Siberian Snake

19. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina19 Preparations for PAX @ AD/CERN PAX target section Electron cooler Siberian snake

20. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina20 Preparations for PAX @ AD/CERN Atomic Beam Source Six additional quadrupoles Breit-Rabi Polarimeter Target chamber: Detector system + storage cell

21. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina21 Preparations for PAX @ AD/CERN PAX low- β section for AD ready for installation

22. Mitglied der Helmholtz-Gemeinschaft June 26, 2012SPIN Physics Workshop in Gatchina22 Collaboration members in PAX@COSY W.Augustyniak r, L. Barion c, S. Barsov d, U. Bechstedt a,b, P. Benati c, S. Bertelli c, V. Carassiti c, D. Chiladze e, G. Ciullo c, M. Contalbrigo c, P.F. Dalpiaz c, S. Dymov g,h, R. Engels a,b, W. Erven i,b, M. Fiorini c, M.Gaisser a,b, R. Gebel a,b, P. Goslawski j, K. Grigoryev d,a,b, G. Guidoboni c, A. Kacharava a,b, A. Khoukaz j, A. Kulikov h, G. Langenberg a,b, A. Lehrach a,b, P. Lenisa c, N. Lomidze e, B. Lorentz a,b, G. Macharashvili h, R. Maier a,b, B. Marianski r, S. Martin a,b, D. Mchedishvili e, S. Merzliakov h,a,b, I.N. Meshkov h, H.O. Meyer k, M. Mielke j, M. Mikirtychiants d,a,b, S. Mikirtychiants d,a,b, A. Nass g,a,b, M. Nekipelov a,b, N.N. Nikolaev a,b,l, M. Nioradze e, D. Oellers a,b,c, M. Papenbrock j, L. Pappalardo c, A. Pesce c, A. Polyanski a,b,f, D. Prasuhn a,b, F. Rathmann a,b, J. Sarkadi a,b, R. Schleichert a,b, A. Smirnov h, H. Seyfarth a,b, V. Shmakova h, M. Statera c, E. Steffens g, H.J. Stein a,b, H. Stockhorst a,b, H. Straatmann m,b, H. Ströher a,b, M. Tabidze e, G. Tagliente n, P. Thorngren Engblom o, S. Trusov p,q, A.Trzcinski r, Y. Valdau a,b,d, A. Vasilyev d, Chr. Weidemann a,b,c, K.M.von Würtemberg o, P. Wüstner i,b, P. Zupranski r a Institut für Kernphysik, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany b Jülich Center for Hadron Physics, 52425 Jülich, Germany c Università di Ferrara and INFN, 44100 Ferrara, Italy d St. Petersburg Nuclear Physics Institute, 188350 Gatchina, Russia e High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi, Georgia f Institute for theoretical and experimental physics, 117218 Moscow, Russia g Physikalisches Institut II, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany h Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, 141980 Dubna, Russia i Zentralinstitut für Elektronik, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany j Institut für Kernphysik, Universität Münster, 48149 Münster, Germany k Physics Department, Indiana University, Bloomington, IN 47405, USA l L.D. Landau Institute for Theoretical Physics, 142432 Chernogolovka, Russia m Zentralabteilung Technologie, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany n INFN, Sezione di Bari, 70126 Bari, Italy o Royal Institute of Technology, Physics Department, SE-10691 Stockholm, Sweden p Institut für Kern- und Hadronenphysik, Forschungszentrum Rossendorf, 01314 Dresden, Germany q Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 119991 Moscow, Russia r National Centre for Nuclear Reserch, 00681 Warsaw, Poland