Oliver KesterI3 EURONSPlan for the extension of 12

month for JRA03

* Double frequency operation of PHOENIX at LPSC (chamber is now available, simpler setup than 28 GHz operation)

* Further exploration of charge state manipulation and comparison with the new simulation tool CBSIM.

* Efficiency exploration with BNL EBIS (can only be done in 2008)

* Continuation of molecule break up and capture of decay products, which opens new possible beam development

Oliver KesterI3 EURONSTask 4: High-frequency exploration of ECRIS

4.1 Improving of breeding time of ECRISalready seen, to be measured systematically before interpratation4.2 High frequency (14-28 GHz) exploration28 GHz might be difficult before end 20084.3 Influence of ECRIS plasma volumeDouble frequency (14+18 GHz will be a good test)

Modifications of the booster under fabrication, will installed by the end of September 2007

Present PHOENI X Breeder Magnetic plug, Higher Binj, Less dissymmetry

UHV tech. and moveable grounded tubeTwo f requency plasma chamber

Oliver KesterI3 EURONSECRIS charge breeders pulsed

LPSCECR charge breeding time

0 2 4 6 8 10 12Time (ms)

Inte

nsit

y (m A

) Ar3+

Ar4+

Ar6+

Ar7+

Ar8+

Ar9+

Ar2+ Microwave pulse

0

800

Steady state Ar9+: 5 ms

Preglow

Afterglow

18 GHz, 950 W 28 GHz, 3600 W

Steady states reached at 3 ms for all charges !!

0 2 4 6 8 10 12Time (ms)

Inte

nsit

y (m A

) Ar3+

Ar4+

Ar6+

Ar7+

Ar8+

Ar9+

Ar2+Microwave pulse

300

0T. Thuillier et al., ICIS’07

In ECR Charge state increase can be very fast ! -> But trapping very long !

0

200

400

600

-800 -600 -400 -200 0

Time (ms)

IRb

15+

(nA

)

End of Rb1+ injection

RF power cancellationRF Power

RB1+ injection Rb15+ Afterglow

Here 520 ms for Rb15+

N. Chauvin et al., Nucl. Instrum. Meth. A, Vol 419, nb. 1, 1998

Charge breeding time is a result of the ECRIS compromise, RF, B, Gas

Oliver KesterI3 EURONSShift of the charge state spectra to

higher charge states

* In Bari rf-excitation (BRIC)* MAXEBIS reduced barrier* Uni Frankfurt fast variation of electron beam current

Can be done by fast removalof hot low charged ions cooling effect

Oliver KesterI3 EURONSCharge state manipulation

methods?

Using atomic shell structure: Beneficial only for heavy ions until now (REXEBIS) Very high abundance in on charge states in EBIT, but at the expense of low efficiency

Using DR resonances: In principle possible (shown at Heidelberg EBIT), but efficiency spoiled by energy spread of the electron beam.

Cooling of highly charged ions: Works for medium heavy and heavy elements survey required

Oliver KesterI3 EURONS Simulation tool: CBSIM

Included so far:

Collision physics:

Stepwise ionisation,charge exchange, RR

Collision and trap physics:

electron-ion-heating,ion-ion cooling

Without charge exchange and recombination, but ion losses

With charge exchange and recombination

Included so far:

Trap physics:

space charge neutralisation andion losses

Soon: atomic data tables

Oliver KesterI3 EURONS

TOF out of the REXTRAP for stable SeCO beam injected

* Molecular sideband beams from ISOLDE to avoid isobaric contamination* e.g. 70SeCO to avoid 70Ge* Keep molecules inside trap, break them in EBIS (or break inside trap with different trap potential settings)

Results

* ~50% SeCO out of trap* 6.5% SeCO+ to Se19+ in EBIS (58 ms breeding time)

* Problems inside the EBIS: ions with high electro-negative values escape the electron beam

* Also tried SrF, BaF, AlF (>16% total efficiency for Al7+)

Molecule breakup (EBIS)

Oliver KesterI3 EURONS 61Mn trapping and ejection

Measurement cycle:

1. RF on, plasma ignited

2. 61Mn injected into the ECR

3. RF is kept on for a time that can be varied (0s, 800ms…)

4. Ejection of the ions as a pulse

0.71s

5.98m

1.65hFrom TOI, R.B. Firestone

Gamma spectrum, 800ms trapping, 61Mn12+ and 61Fe12+ extracted

FeMn

Fe FeMn

Fe Fe Fe

Energy (keV)

cnts

Oliver KesterI3 EURONS Emittance measurements ECRIS

Two 1+ and two n+ identical emittancemeters are setup in the beamLine of LPSC and are working RMS emittances absolute (20 kV*q)

Xplane: 84Kr15+ Y plane: 84Kr15+ Xplane: 84Kr1+ Y plane: 84Kr1+

norm. ~0.015 mm mrad norm ~0.06 mm mrad