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Implementation of titanium:sapphire lasers at ISOLDE RILIS. S. Rothe , V.N. Fedosseev , D. Fink, B.A. Marsh, R.E. Rossel , M. Seliverstov and K. Wendt. ISOLDE Workshop 2011. Outline. The RILIS principle The new solid- state laser system RILIS operation 2011 - PowerPoint PPT Presentation
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Implementation of titanium:sapphire lasers
at ISOLDE RILIS
ISOLDE Workshop 2011
S. Rothe, V.N. Fedosseev, D. Fink, B.A. Marsh, R.E. Rossel, M. Seliverstov and K. Wendt
ISOLDE Workshop 2011 2Implementation of titanium:sapphire lasers at ISOLDE RILIS
Outline
• The RILIS principle
• The new solid-state laser system
• RILIS operation 2011
• In-source laser spectroscopy of Astatine
ISOLDE Workshop 2011 3Implementation of titanium:sapphire lasers at ISOLDE RILISMagnet set to A = 205
The Resonance Ionization Laser Ion Source (RILIS)
• Simple setup at target site: same as surface ion source
• RILIS lasers excite and ionize atomsZ selectiveGround State
Excited States
Rydberg State
Auto-ionizing State
Ionization potential
Laser ionization scheme
At
Laser tuned to Z = 85
205AtIsotope of interest
Laser Ion Sourceline targetlaser beams
ISOLDE Workshop 2011 4Implementation of titanium:sapphire lasers at ISOLDE RILIS
Pump laser: Nd:YAG (532 nm)Repetition rate: 10 kHz, Pulse duration: 9 nsPower: 100 W
The RILIS dye lasers
dye lasers:2 x broadband (6 GHz)1 x narrow band (1 GHz)
Rh6GRh110Pyridin 1Rhod BEozinPyrromethene 567Pyrromethene 597Fluorescein 27Phenoxazone 9 +H2OPhenoxazone 9Styryl 9Styryl 8DCM
550 600 650 700 750 800 85005
101520253035
efficie
ncy (
%)
wavelength (nm) > 10 different dyes used Laser table Jan. 2011
After CVL removal 2010
ISOLDE Workshop 2011 5Implementation of titanium:sapphire lasers at ISOLDE RILIS
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
0
500
1000
1500
2000
2500
Year
Ope
ratio
n pe
r yea
r (h)
Realistic curve for one laser system
demand
RILIS operation 1994 to 2010
ISOLDE Workshop 2011 6Implementation of titanium:sapphire lasers at ISOLDE RILIS
LISOLLouvain-la-Neuvegas cellrep. rate <200Hzdye laser
ISOLDE, Genevahot cavityrep. rate 10 kHzdye laser
RILISFURIOSJyväskylägas cellrep. rate ~10 kHzti:sa & dye laser
ORNLOak Ridge (off-line)
hot cavity rep. rate ~10 kHzti:sa laser
TRILISVancouverhot cavity rep. rate ~10 kHzti:sa laser
TIARATakasakihot cavityrep. rate 300Hzdye laser
? gas catcher ?
RIKEN
? hot cavity ?
ALTO Selection only. updated from C. Geppert (2007) V.Fedosseev (2010)
? hot cavity ?
SPES
GISELE Caen (off-line)
rep. rate ~10 kHzti:sa laser
Gatchinahot cavityrep. rate ~10 kHzdye laser
PNPI
RISIKO Mainz (off-line)
rep. rate ~10 kHzti:sa laser
Laser ion sources World-Wide
ISOLDE Workshop 2011 7Implementation of titanium:sapphire lasers at ISOLDE RILIS
Dye Ti:SaActive Medium > 10 different dyes =1 Ti:sapphire crystalcondition of aggregation liquid (org. solvents) solid-stateTuning range 540 – 850 nm 680 – 980 nmPower < 12 W < 5 WPulse duration ~8 ns ~50 nsSynchronization optical delay lines q-switch, pump power# of schemes developed 47 37Maintenance renew dye solutions ~ none
Comparison dye vs. Ti:Sa system
200 300 400 500 600 700 800 900
0.10.20.51.02.05.0
10.0
wavelength nm
Ti:Sa
Dye
2x Ti:Sa2x Dye
3x Ti:Sa
4x Ti:Sa3x Dye
550 600 650 700 750 800 850 900 950
0
5
10
15
20
25
30
35
effic
ienc
y(%
)
wavelength (nm)
Dye
Ti:Sa
Ti:Sa system is complementary
ISOLDE Workshop 2011 8Implementation of titanium:sapphire lasers at ISOLDE RILIS
The Ti:Sa laserend mirror etalon birefringent tuner
laser crystal
output couplerpump beam
3d model• Mainz-Type• Design optimized for
on-line operations
Prototype• Machined at Mainz
University workshop
Serial production
Lasing medium: • solid-state Ti doped
sapphire (Ti:Al2O3)• Hardness 9
Serial production• 3 Ti:Sa modules available
ISOLDE Workshop 2011 9Implementation of titanium:sapphire lasers at ISOLDE RILIS
The RILIS Ti:Sa lasers
Wavelength tuning range:• Fundamental (w) 690 - 940 nm (5 W) • 2nd harmonic (2w) 345 - 470 nm (1 W)• 3rd harmonic (3w) 230 - 310 nm (150 mW)• 4th harmonic (2w) 205-235 nm (50 mW)
Change of mirror sets in resonatorNo amplifier yet availableNo ageing
700 750 800 850 900 9505
10
15
20
25
30
lass
ing
effic
ienc
y(%
)
wavelength (nm)
SP4440SP4444SP0000SP1000SP1111SP1110
100 mm
Pump laser: Nd:YAG (532 nm)Repetition rate: 10 kHzPulse length: 180 nsPower: 60 W
Ti:Sa lasers:Line width: 5 GHzPulse length: 30-50 ns
6 resonator mirrorsets cover the Ti:Sa range
ISOLDE Workshop 2011 10Implementation of titanium:sapphire lasers at ISOLDE RILIS
RILIS Dye Laser System GPS/HRS
Target & Ion Source
l – meterDye 2 SHG
Narrowband Dye
THGDye 1
Nd:YAG
10 kHz Master clock
Dye RILIS
ISOLDE Workshop 2011 11Implementation of titanium:sapphire lasers at ISOLDE RILIS
RILIS Dye Laser System GPS/HRS
Target & Ion Source
RILIS Ti:Sa Laser System
pA – meter
Faraday cup…
SHG/THG/FHG
l – meter
Ti:Sa 2
l – meterDye 2 SHG
Narrowband Dye
THGDye 1
Ti:Sa 1
Ti:Sa 3
Nd:YAG
Nd:YAG
10 kHz Master clock
Delay generator
LabVIEW based DAQ
Ti:Sa & Dye RILIS
ISOLDE Workshop 2011 12Implementation of titanium:sapphire lasers at ISOLDE RILIS
RILIS in operation
ISOLDE Workshop 2011 13Implementation of titanium:sapphire lasers at ISOLDE RILIS
RILIS in operation
ISOLDE Workshop 2011 14Implementation of titanium:sapphire lasers at ISOLDE RILIS
Sm Ga Mg At Pb Dy Nd Pr Ag Tl Cd Mn Ni Dy Yb Zn
89 101146
269221
35
110
4
92
231 241
390348
6013
407real plan
RILI
S op
erati
on 2
011
(h)
RILIS operation 2011
Ion beams of 16 elements were produced since beginning of the running period: • 2573 h for on-line experiments • Ti:Sa system used already with 9 elements• Some additional tests only feasible because of the ‘spare’ laser system
Ti:Sa involvement
ISOLDE Workshop 2011 15Implementation of titanium:sapphire lasers at ISOLDE RILIS
Ti:Sa only mode100 W Nd:YAG laser available for non-resonant ionization
Mixed modeCombination of dye and Ti:Sa
Backup modedye and Ti:Sa are
exchangeable
Highest efficiencies New RILIS elements Reduction in down time
New modes of operation – The Dual RILISCondition for dual operation: Temporal synchronization of the two laser systems
ISOLDE Workshop 2011 16Implementation of titanium:sapphire lasers at ISOLDE RILIS
a) Photoionization threshold : 75129(95) cm-1
b) Scan for 2nd step transitions (at TRIUMF)
c) Verification of levels, yield measurements
d) Scan of ionizing laser: converging Rydberg levels allow precise determination of the IP
532
nm
224
nm
216
nm31
2 - 3
35 n
m
609-
645
nm
a) b) c)
795
nm
532
nm
44550 cm-1
0 cm-1
46234 cm-1
57157 cm-1
57269 cm-1
57277 cm-1
58805 cm-1
75151 cm-1
710-
915
nm
d)
E𝑛=E IP−RM
(𝑛−𝐴+ 𝐵(𝑛−𝐴 )2 )
2
Rydberg-Ritz formula
EIP(At) =75151(1) cm-1
preliminary
16150 16200 16250 16300 16350
0
10
20
30
ion
curr
ent
(pA
)
wavenumber (cm -1)
10 36
preliminary
0 5 10 15 20 25 30 35
15800
16000
16200
wav
enum
ber
(cm
-1)
n'
0 10 20 30
-0.50.0
0.5
resi
dual
s(c
m-1)
n'
Phys. Rev. Letter in preparation
At in-source spectroscopy
ISOLDE Workshop 2011 17Implementation of titanium:sapphire lasers at ISOLDE RILIS
Summary• A complementary second laser system of Ti:Sa lasers was installed at RILIS• RILIS operated smoothly >2500 h in 2011• Dual RILIS (Combined dye and Ti:sapphire laser system) is in regular
operation• In-source laser spectroscopy of Astatine led to development of an
efficient ionization scheme and first and precise determination of the ionization potential
Outlook / Comments• RILIS scheme development could become partly opportunistic (e.g. astatine)• Machine protection, monitoring and remote control progressing• For Ti:Sa-only schemes RILIS could operate in on-call mode very soon• RILIS scheme database (cern.ch/riliselements) in beta phase
ISOLDE Workshop 2011 18Implementation of titanium:sapphire lasers at ISOLDE RILIS
Acknowledgements
KTH – Royal Institute of Technology &Knuth and Alice Wallenberg FoundationStockholm, Sweden
CERN, EN-STI
University of Mainz, Working group LARISSAMainz, Germany
The Wolfgang-Gentner-Programme of the Bundesministerium für Bildung und Forschung (BMBF)
RILIS - Team
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