On-line tests RFQ cooler ISCOOL A quick summary P. Delahaye, H. Frånberg, I. Podadera ISCOOL, COLLAPS, ISOLDE collaboration

Where at ISOLDE

Installation in pictures

Principle Three elements: RF quadrupolar field  Radial confinement DC potentials  Extracting ion in bunches or in continuos mode Buffer gas  Ion motion cooling

Emittance measurements Without cooling With cooling ~35  ·mm·mrad 95% emittance ~2.2  ·mm·mrad 95% emittance

Transmissions Potentials along the axis Transmissions in DC – 23 Na: 50% – 39 K: >75% – 85 Rb: >75% Better than the off-line tests! Smaller emittances from ISOLDE surface ion sources than from the ion source used during off- line tests. 80eV 5-2V/cm ~1E-2 mbar 4 He mbar l/s EXTRACTION INJECTION 50V (30V enough) TRAPPING

Cooling time TOF < 1ms from the entrance to the exit of the RFQ 1 passage is enough to get a cold beam –as measured off-line, and other labs as predicted by simulations for other systems

Bunching mode 30keV 80eV 5-2V/cm ~1E-2 mbar 4 He mbar l/s EXTRACTION INJECTION 50V (30V enough) TRAPPING

Space charge limits Up to 10 8 /s!! As measured with FC (data under analysis with MCP) 39 K 85 Rb

Bunch width Depends on the space charge and cooling time Collection / cooling time

Preliminary results Data from 26 Na needs to be analyzed Losses due to trapping time (analysis in progress) Chemistry, noble gases, reactive elements More data needed for more masses (light ions) –CaO target + plasma ion source should provide some answers

ISCOOL TEST 46 K Beam 1E5 ions/s after the cooler. Collection time 20 minutes, with 300ms bunching and a 12us gate and 2mW of laser power. Singles (continuous counting) Bunched:12us gated spectra Background suppression factor~1E4

Thanks to: AB-OP-PSB-iso team: Pascal, Erwin, Magnus, Emiliano and Tim. AB/ATB AB/CO AB/PO AB/VAC SC/RP ISOLDE collaboration COLLAPS collaboration ISCOOL collaboration