1. - 9 th Sep. 2009 - Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano Development of a Beam Profile Monitor Based on a Supersonic Gas-Jet Curtain GSI Talk, Darmstadt Website: www.quasar-group.org Email: massimiliano.putignano@quasar-group.org

2. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 1/9 a Beam Profile Monitor using a Gas Jet? a Beam Profile Monitor using a Gas Jet? USR Project at FLAIR (FAIR facility, Darmstadt) - Ultra-low energy pbars (20-300 keV) - Coasting/bunched beam - Low pressure (10 -11 mbar) Low perturbation AND high count rate Investigation of the Gas-Jet A. Papash and C. P. Welsch, Physics of Particles and Nuclei Letters, Vol. 6, No. 3. (2009), pp. 216-226. Inclusion in the Reaction Microscope Log. Pressure Log. Reaction Rate Why Why

3. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 2/9 does it work? does it work? How

4. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 3/9 do we start? State-of-the-art Detailed study of expansion structure Assessment of the impact on jet parameters Optimization of axis-symmetric jet for use as a target. All optimization studies performed for an axis-symmetric jet. Identify parameters of interest to diagnostics. Identify parameters of interest to diagnostics. Propose a novel nozzle-skimmer system. Propose a novel nozzle-skimmer system. Extend existing studies to planar jets. Extend existing studies to planar jets. M.Jugroot et al: Numerical investigation of interface region flows in mass spectrometers: neutral gas transport – J. Phys. D: Applied Physics, vol. 37 (2004) pp 1289. Where

5. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 4/9 Jet structure calculations Governing equations – – Continuity Equation A statement of conservation of mass – – Energy Equation Resulting from neglecting thermal and viscous effects – – Momentum Equation (Euler’s Equation) A statement of conservation of momentum – – Equation of State Ideal gas equation of state (from kinetic theory) – – Thermal Equation of state Definition of int. energy and measurement of specific heat.

6. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 5/9 variables and observables do we choose? -2 dB Attenuation   SW SD Dist Dist.   – angle of skimmer aperture in the direction of curtain expansion;   – angle of skimmer aperture in the direction perpendicular to curtain expansion SW SW – skimmer slit width SD SD – skimmer depth Dist Dist – nozzle-skimmer distance M max M max – Maximum Mach Number CM max M max70% CM max – Coordinates maximum M M max70% - Maximum M at 70% simulation domain distance from nozzle W D W – Curtain width (at -2 dB attenuation); D – Curtain depth (at -2dB attenuation); Which

7. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 6/9 What do we find? Curtain behavioral trends

8. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 7/9 Simulations output System can be optimized through nozzle-skimmer geometry. Slit nozzle (instead of circular nozzle) Nozzle and skimmer slits have to be perpendicular Shaping of the gas curtain is feasible. Actual value of quality ratio: W/D. 2-3 Decreases of a factor of 2-3 moving from Slit nozzle to Circular nozzle. Homogeneity of curtain:  /  = Nozzle-Skimmer system: PerpendicularParallel 89% 68% -2 dB Attenuation

9. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 8/9 and now? Differential Pumping (20 mm range) (5 o range) Longitudinal (20 mm range) and angular (5 o range) fine tuning. ow! W …

10. Introduction Gas-Jet Simulations Experimental Setup Massimiliano Putignano - 9 th Sep 2009 - Slide 9/9 Who do I thank? Acknowledgements: – Kai-Uwe Kühnel – Angela Intermite – Carsten P. Welsch References: 1.M.Putignano et al: A Fast, Low Perturbation Ionization Beam Profile Monitor Based on a Gas-jet Curtain for the Ultra Low Energy Storage Ring - Hyperfine Interaction, accepted. 2.M.Putignano et al: Design of a nozzle-skimmer system for a low perturbation ionization beam profile monitor – DIPAC09 Proceedings. 3.M.Jugroot et al: Numerical investigation of interface region flows in mass spectrometers: neutral gas transport – J. Phys. D: Applied Physics, vol. 37 (2004) pp 1289. 4.Y. Hashimoto et al: Oxygen gas-sheet beam profile monitor for the synchrotron and storage ring - Nucl. Instr. Meth. Phys. Res. A 527 (2004) 289. Thank you for your attention