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- 9- 9thth Sep. 2009 - Sep. 2009 - Introduction Gas-Jet Simulations Experimental Setup
Massimiliano PutignanoMassimiliano Putignano
Development of a Beam Profile Monitor Based Development of a Beam Profile Monitor Based on a Supersonic Gas-Jet Curtainon a Supersonic Gas-Jet Curtain
GSI Talk, DarmstadtGSI Talk, Darmstadt
Website:Website: www.quasar-group.orgwww.quasar-group.orgEmail:Email: [email protected] [email protected]
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 22/9/9
Introduction Gas-Jet Simulations Experimental Setup
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
Reaction Rate (events/s)
0
1
2
3
4
5
6
7
-10 -9 -8 -7 -6 -5 -4
Log. Pressure at 300 K (mbar)
Log.
Rea
ctio
n R
ate
(eve
nts/
s)
1 mm2 mm5 mm
Log. PressureLog.
Rea
ctio
n Ra
te
WhyWhy
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 33/9/9
Introduction Gas-Jet Simulations Experimental Setup
does it work?does it work?HowHow
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 44/9/9
Introduction Gas-Jet Simulations Experimental Setup
do we start?do we start?
State-of-the-artState-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.
• IdentifyIdentify parametersparameters of interest to diagnostics.of interest to diagnostics.• Propose a Propose a novel nozzle-skimmer systemnovel nozzle-skimmer system..• Extend existing studiesExtend existing studies to planar jets.to planar jets.
M.Jugroot M.Jugroot et alet al: : Numerical investigation of Numerical investigation of interface region flows in mass spectrometers: interface region flows in mass spectrometers: neutral gas transportneutral gas transport – J. Phys. D: Applied – J. Phys. D: Applied Physics, vol. 37 (2004) pp 1289.Physics, vol. 37 (2004) pp 1289.
WhereWhere
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 55/9/9
Introduction Gas-Jet Simulations Experimental Setup
Jet structure calculationsJet 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.
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 66/9/9
Introduction Gas-Jet Simulations Experimental Setup
variables and observables do we choose?variables and observables do we choose?
-2 dB Attenuation
SSWW
SDSD
DisDistt.
– angle of skimmer aperture in the direction of curtain expansion; – angle of skimmer aperture in the direction perpendicular to curtain expansionSWSW – skimmer slit widthSDSD – skimmer depthDistDist – nozzle-skimmer distance
MMmaxmax – Maximum Mach NumberCMCMmax max – Coordinates maximum MMMmax70%max70% - Maximum M at 70% simulation domain distance from nozzleWW – Curtain width (at -2 dB attenuation); DD – Curtain depth (at -2dB attenuation);
WhichWhich
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 77/9/9
Introduction Gas-Jet Simulations Experimental Setup
WhatWhat do we find? do we find?
Curtain behavioral trendsCurtain behavioral trends
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 88/9/9
Introduction Gas-Jet Simulations Experimental Setup
Simulations outputSimulations 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.
Decreases of a factor of 2-32-3 moving from Slit nozzle to Circular nozzle.Homogeneity of curtain: / =Nozzle-Skimmer system:
Perpendicular Parallel 89% 68%89% 68% -2 dB
Attenuation
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 99/9/9
Introduction Gas-Jet Simulations Experimental Setup
and now?and now?
• Differential Pumping• Longitudinal (20 mm (20 mm range) range) and angular (5(5o o range)range) fine tuning.
ow!ow!WW……
Massimiliano Putignano Massimiliano Putignano - 9- 9thth Sep 2009 - Sep 2009 - Slide Slide 1010/9/9
Introduction Gas-Jet Simulations Experimental Setup
WhoWho do I thank? do I thank?
• Acknowledgements:– Kai-Uwe KühnelKai-Uwe Kühnel– Angela IntermiteAngela Intermite– Carsten P. WelschCarsten P. Welsch
• References:1.1. M.Putignano M.Putignano et alet al: : A Fast, Low Perturbation Ionization Beam Profile Monitor Based on a A Fast, Low Perturbation Ionization Beam Profile Monitor Based on a
Gas-jet Curtain for the Ultra Low Energy Storage RingGas-jet Curtain for the Ultra Low Energy Storage Ring - Hyperfine Interaction, accepted. - Hyperfine Interaction, accepted.2.2. M.Putignano M.Putignano et alet al: : Design of a nozzle-skimmer system for a low perturbation ionization Design of a nozzle-skimmer system for a low perturbation ionization
beam profile monitorbeam profile monitor – DIPAC09 Proceedings. – DIPAC09 Proceedings.3.3. M.Jugroot M.Jugroot et alet al: : Numerical investigation of interface region flows in mass spectrometers: Numerical investigation of interface region flows in mass spectrometers:
neutral gas transportneutral gas transport – J. Phys. D: Applied Physics, vol. 37 (2004) pp 1289. – J. Phys. D: Applied Physics, vol. 37 (2004) pp 1289.4.4. Y. Hashimoto Y. Hashimoto et alet al: : Oxygen gas-sheet beam profile monitor for the synchrotron and Oxygen gas-sheet beam profile monitor for the synchrotron and
storage ringstorage ring - Nucl. - Nucl. Instr. Meth. Phys. Res. A 527 (2004) 289.Instr. Meth. Phys. Res. A 527 (2004) 289.
Thank you for your attentionThank you for your attention