Zoran Andjelkovic

1
SPECTRAP meeting status report
Zoran Andjelkovic Johannes Gutenberg Mainz
University GSI Darmstadt
Laser Spectroscopy of Highly Charged Ions and
Exotic Radioactive Nuclei (Helmholtz Young
Investigator Group)
2
A short progress overview

• Introduction
• HITRAP overview
• magnet trap
• Beamline detectors
• transporting the ions
• deceleration
• necessary modifications
• Current status and measurements
• candidates
• status
• time plan

3
Overview of the HITRAP Facility
UNILAC
Experiments with particles at rest
Cooler trap
SIS
400 MeV/u
HITRAP
Stripper target

• SPECTRAP
• trapping of HCI
• cooling nearly to rest
• laser spectroscopy of HFS

U92 Pb81 Bi80,82
ESR
4 MeV/u
Electron cooling and deceleration
4
system overview

• ions from
• sputter gun (Ar)
• oven (Mg)
• EBIT (mid Z)
• HITRAP (high Z)

5
trap overview
6
added mirrors and lenses

• increased fluorescence rate (solid angle)
• low wavelengths not reachable

7
beam transport

• simulations by Shailen Bharadia
• beam waist measurements with a 4-jaw slit
• slight deformation after bending
• good trasport efficiency, injection into the B
  field

8
decelerating ions

• two stage deceleration
• deceleration efficiency of some 90 (energy not
  sharp)
• simulations inside B field even better

9
0 V
2,5 keV
10 eV
-2490 V
2490 V
0 V
1500 V
-990 V
SIMION simulations by Dirk Tiedemann
10
detectors

• Destructive
• MCP in-line
• Channeltron for off-axis detection
• Non-destructive
• Resonant detection inside the trap
• Arrival detector

detect
endcap
L
R
C
from an endcap
excite
endcap
11
current layout extensions
new He recovery line
to be mounted MCP to be mounted channeltron
an extension needed
a small platform extension
12
hyperfine transition measurements
Type Ion Transition l nm A 1/s
H-like 165Ho66 F3 F4 572.6 -
H-like 185Re74 F2 F3 456.5 -
H-like 187Re74 F2 F3 452.2 -
H-like 203Tl80 F0 F1 386.3 -
H-like 205Tl80 F0 F1 382.6 -
H-like 207Pb81 F0 F1 1019.7 20
H-like 209Bi82 F4 F5 243.9 2849
H-like 235U91 F3 F4 1538 9
Li-like 209Bi80 F4 F5 1514 12
13
or fine transitions im mid Z
Group Ion Conf. Transition l nm A 1/s
IIIA (16)S11 2s22p 2P1/2-2P3/2 761.10 21
IIIA (18)Ar13 2s22p 2P1/2-2P3/2 441.24 104
IIIA (26)Fe13 3s23p4 2P1/2-2P3/2 530.29 60
IIIA (27)Co14 3s23p 2P1/2-2P3/2 435.06 109
IVA (20)Ca14 2s22p2 3P0-3P1 569.44 95
IVA (21)Sc15 2s22p2 3P0-3P1 435.44 208
IVA (22)Ti16 2s22p2 3P0-3P1 337.08 440
IVA (23)V17 2s22p2 3P0-3P1 263.36 921
IVA (33)As19 3s23p4 3P0-3P1 243.80 1100
14
or just to have a slow start...

• trapping Ar2
• readily available in large quantities
• spectroscopy difficult if not impossible
• trapping and laser cooling of Mg
• easy to trap, laser available
• a bit problematic to produce
• combination of the two
• Pb
• strong interest in the results
• very difficult to produce
• difficult to trap

15
the resonant frequencies
16
Current status

• We have
• platform with infrastructure
• assembled beamline
• experimental control electronics (LabVIEW
  oriented)
• cryo-electronics almost ready

• We want
• an ion source
• electronics, detectors...

• Next steps
• connect the cryo-electronics and wire the trap
• prepare an ion source (sputter gun, oven, EBIT?)
• cool down the magnet and the fun starts...

17
and now for something completely different...
TIME PLAN!
month 03 04 05 06 07 08 09 10 11 12
Cryo-electronics done x
Modify the platform, beamline x x
Trap instalation and wiring x x
Trapping, testing, practicing x x x
Cooling down x x x x
Initial experiments x x ... ...
Zoran hopefully no lab work x x