1. PIPERADE: A Penning trap isobar separator for SPIRAL2/DESIR
P. Ascher1, G. Ban2, B. Blank3, K. Blaum1, J.- F. Cam4, P. Delahaye4, F. Delalee3, P. Dupré5, S. El Abbeir3, M. Gerbaux3, S. Grevy3, G. Grinyer4, H. Guérin3, M. Heck1, E. Liénard2, D. Lunney5, S. Naimi1, L.Perrot6, A. de Roubin1,3, L. Serani3, J.-C. Thomas4
1 Max Planck Institut für Kernphysik, Heidelberg, Germany
2 Laboratoire de Physique Corpusculaire, Caen, France
3 Centre d’Etudes Nucléaires de Bordeaux-Gradignan, France
4 Grand Accélérateur National d’Ions Lourds, Caen, France
5 Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, Orsay, France
6 Institut de Physique Nucléaire Orsay, France
Pauline Ascher - Colloque GANIL - Port-en-Bessin, 23th – 27th September 2013

2. DESIR facility
10 – 60 keV exotic nuclides beams delivered by Spiral1 / Spiral2 / S3
3 main tools: Beta Decay spectroscopy (BESTIOL) Decay Laser spectroscopy (LUMIERE) Excitation
Ion / atom trapping (DETRAP) Storage

3. PIPERADE requirements Requirements for the device
Goal of PIPERADE: deliver very pure and large samples of exotic nuclei to the DESIR set-ups
Requirements for the device
Mass resolution > 105 (Isobaric cleaning)
Purify very large samples of ions (> 105 ions/bunch)
(Large ratio contamination/ions of interest, high relative intensity also for the molecules )
"Fast" cleaning process (50 – 500 ms)
double-Penning trap system 3

4. See poster of Hugo Guérin for more details about this RFQ
The PIPERADE system
PIPERADE will consist of
An ion source (FEBIAD source)
to calibrate the system, perform off-line measurements and deliver stable beams to DESIR
already in operation at CENBG
A radiofrequency quadrupole (RFQ/GPIB)
to cool and bunch the beam
under construction at CENBG
Isobar separator and accumulator (double- Penning trap)
to purify the beam from the undesired species and accumulate the ions of interest
under study at CSNSM/MPIK
See poster of Hugo Guérin for more details about this RFQ
B. Blank et al, IJMS (2013) P. Ascher et al, submitted to EPJ Web of Conference 4

5. See poster of Antoine de Roubin
The PIPERADE system
PIPERADE will consist of
An ion source (FEBIAD source)
to calibrate the system, perform off-line measurements and deliver stable beams to DESIR
already in operation at CENBG
A radiofrequency quadrupole (RFQ/GPIB)
to cool and bunch the beam
under construction at CENBG
Isobar separator and accumulator (double- Penning trap)
to purify the beam from the undesired species and accumulate the ions of interest
under study at CSNSM/MPIK
Pulsed Drift Tubes are needed for the injection in the PT (60keV → 100 eV)
See poster of Antoine de Roubin B
B. Blank et al, IJMS (2013) P. Ascher et al, submitted to EPJ Web of Conference 5

6. Penning trap
Trapping (i.e. confinement in all 3 dimensions) obtained by the superposition of
homogeneous magnetic field (radial confinement) wc= qB/m
electrostatic quadrupolar field (axial confinement)
3 independent motions at 3 eigenfrequencies
endcap
ring
endcap
K. Blaum et al., Phys. Rep. 425, (2006)

7. The double Penning trap
Diaphragm
Purification trap
Accumulation trap
R = 3,2 cm
L = 26 cm
R = 1 cm
L = 8 cm
… installed in a superconducting magnet of 5/7 Tesla with 2 specific homogeneous regions
Many cycles (purification + storage) + final cleaning (decay products) before sending large samples to experiments
A diaphragm will be placed between the two traps to act as a pumping barrier and to eject selectively the ions of interest which are centered 7

8. FT-ICR detection „FT-ICR“ x A I y t f
Fourier Transform Ion Cyclotron Resonance
Ring-Pickup-Electrode
mass
spectrum
ion current
signal x y A I t f
Ring-Pickup-Electrode

9. Isobar separation in a Penning trap
Sideband buffer gas cooling:
Dipolar excitation at the magnetron frequency w- (mass independent, all the ions are brought to a higher radius)
Combining the effect of buffer gas and the use of a quadrupolar excitation at wc
- buffer gas: cyclotron motion is cooled, magnetron motion increases
- quadrupolar excitation: coupling the two radial modes
buffer gas + quadrupolar excitation
only buffer gas
t=0
t=0
G. Savard et al, Phy.Lett. A 158, (1991) 9

10. Buffer gas cooling with many ions
SIMBUCA program , S. Van Gorp et al., NIM A 638, (2011)
90% 136Te, 10% 136Sb
P = 10-4 mbar
Time(ms)
1000 ions
R(mm)
Time(ms)
R(mm)
5000 ions
Time(ms)
R(mm)
12000 ions
Increasing the number of ions
makes the re-centering inefficient

11. Space charge effects f-shifts peak broadening screening effects
How to avoid or limit these effects?
Expand the cloud to decrease the density
Big trap
Antisymetric Rotating Wall technique, SWIFT, etc…
Determine the frequency shifts
Investigate other separation methods (SIMCO excitation, Dipole cleaning, Ramsey cleaning, SWIFT technique etc…)
Simulations in progress
Tests underway at a FT-ICR setup atMPIK Heidelberg

12. Timeline of the project
Tests of the RFQ built in Bordeaux
Build and test the traps at MPIK FC
MCP/FC
Post-amplifiers
Superconducting magnet (4,7Tesla)
Surface ionization source (6,7Li)

13. Timeline of the project
Tests of the RFQ built in Bordeaux
Build and test the traps at MPIK
Test the complete PIPERADE system in Bordeaux
Installation at DESIR IS
RFQ
steerers and quadrupoles
Switch HRS / PT
superconducting magnet

14. … the PIPERADE collaboration … and you for your attention!
Thanks to…
… the PIPERADE collaboration
G. Ban, B. Blank, K. Blaum, J.- F. Cam, P. Delahaye, F. Delalee, P. Dupré, S. El Abbeir, M. Gerbaux, S. Grévy, G. Grinyer, H. Guérin, M. Heck, E. Liénard, D. Lunney, S. Naimi, L. Perrot, A. de Roubin, L. Serani, B. Thomas and J.-C. Thomas
… and you for your attention!