Precision spectroscopy of HCI in a reaction microscope Max-Planck-Institut für Kernphysik, Heidelberg C. Dimopoulou HITRAP Meeting, May 2005, Munich

Goal: study charge transfer processes in collisions between HCI and atoms/molecules/clusters MPI-K HITRAP Task: develop a reaction microscope (COLTRIMS spectrometer) Milestone: tests of the reaction microscope with light HCI

example: 3  10 4 Kr 30+ ions/s Extraction of HCI from the HD-EBIT ion beam size: ~5 mm (FWHM) magnetic field  sqrt(M/q), [arb.units] count rate

Reaction Microscope Coincident measurement of momentum vectors of charged collision fragments Target Jet Ion Detector Projectile detector HCI Beam Cold atomic/molecular target E-field HCI beam E~keV/u Scattered projectile recoil target ions E-field position sensitive detectors

HCI beam Target Jet recoil ion detector EBIT Projectile detector Extraction of HCI (e.g. Ne 10+, Ar 18+, Kr 34+, U 64+, Xe 54+ ) Tests with HCI from the EBIT: The electron capture experiment E-field He target HCI beam E-field recoil ions He + He 2+ tt TOF: target ion charge state long. momentum Position: trans. momentum PSD

Tests with HCI from the EBIT: The electron capture experiment E-field He target HCI beam E-field recoil ions He + He 2+ tt TOF: target ion charge state long. momentum Position: trans. momentum PSD

Electron capture: Precision spectroscopy Ne 6+ 9 keV/q Ne 7+ p r|| = Q /v p -v p /2  p r   p p i v P = 0.36 a.u.  He + p r p p f p p i  p p  p r

,0 0,1 0,2 0,3 0,4 Q-value /eV scattering angle  / mrad Scattering angle / mrad Q-value /eV Electron capture: Precision spectroscopy excellent resolution: 0.7eV FWHM excellent precision: meV many states resolved simultaneously no selection rules HITRAP: ultimate Q-value resolution  p r||   Q / v p

Single electron capture in 12 keV/q Ar 16+ -He collisions Q-value (eV) Q value (eV) :Q = E b f - E b i Structure Dynamics scattering angle (mrad) cross section (arb.u.)

From light to heavy HCI ?

14 keV/q U 64+ ( ions/s) on He cross section (arb.u.) Q value (eV) :Q = E b f - E b i cross section (arb.u.) scattering angle (mrad) Structure Dynamics First capture experiment with U 64+ ions

Increased Acceptance for recoil ions: large ion detector (MCP) with hole in preparation The HITRAP reaction microscope

HCI beam Target: gas-jet recoil ion detector EBIT Projectile detector Systematic study of EC for bare noble gas ions up to Xe 54+ on He Collaboration with S.Knoop, Groningen Summary & Outlook Future: Installation at HITRAP Reaction microscope: ready and tested in EC experiments with HCI from the EBIT

1.Precision Spectroscopy 2.Dynamics of formation: many-electron flux 3. Rearrangement processes Questions : Formation of ”hollow atoms” HCI from HITRAP HCI Target  X-rays Auger cascades E~keV/u Reaction microscope Studies with HCI at HITRAP  Coincident detection of ions, electrons and photons  t ≈ 1 fs

R. Moshammer, J. R. Crespo Lopez-Urrutia, D. Fischer, C. Dimopoulou, T. Ferger, G. Sikler, H. Tawara, A. Gonzalez, R. Soria, G. Brenner, J. Braun, H. Bruhns, B. Feuerstein, J. Ullrich Max-Planck Institut, Heidelberg KVI, Groningen Former collaborators V. Mironov, C. Osborne, A. Lapierre, M. Trinczek S. Knoop, R. Hoekstra People