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RILIS developments and activities during LS1. Presented to Standing group for the upgrade of the ISOLDE facility January 28, 2013 By V. Fedosseev. The 3 stages of RILIS Upgrade. The pump laser upgrade 1 : Change from copper vapour laser (CVL) to commercial Nd:YAG laser
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RILIS developments and activities during LS1 Presented to Standing group for the upgrade of the ISOLDE facility January 28, 2013 By V. Fedosseev
The 3 stages of RILIS Upgrade • The pump laser upgrade1: • Change from copper vapour laser (CVL) to commercial Nd:YAGlaser Aim: Maintain or improve the dye laser performance whilst increasing the reliability of the overall system. • The dye laser upgrade: • 3 New state of the art dye lasers to replace the original dye lasers Aim: Improve the dye laser performance, ease of use and reliability, make full use of the capabilities of the new pump laser. • Install an independent and complementary Ti:Sa based RILIS laser setup2,3 : • 2 pump lasers and 3 Ti:Sa lasers plus harmonic generation units Aim: Extend the tuning range of the RILIS setup to enable access to the large number of ionization schemes developed for Ti:Sa lasers. Reduce switching time between elements to allow for more condensed scheduling of RILIS runs. 1 The ISOLDE RILIS pump laser upgrade and the LARIS Laboratory B. Marsh et al: Hyperfine Interactions, Volume 196, Issue 1-3, pp. 129-141 (2010) 2A complementary laser system for ISOLDE RILIS S Rothe et al: Journal of Physics: Conference Series 312 (2011) 052020 3 Upgrade of the RILIS at ISOLDE: New lasers and new ion beams V. Fedosseev et al: Rev. Sci. Instrum. 83, 02A903 (2012)
Dual RILIS Concept Nd:YAG Dye 2 Nd:YAG Dye 2 l–meter SHG l–meter SHG Dye 1 THG Dye 1 THG 10 kHz Master clock 10 kHz Master clock NarrowbandDye NarrowbandDye RILIS Dye Laser System RILIS Dye Laser System GPS/HRS GPS/HRS Delay generator RILIS Ti:Sa Laser System Target & Ion Source Target & Ion Source Nd:YAG Ti:Sa 1 SHG/THG/FHG Ti:Sa 2 Faraday cup… Ti:Sa 3 l–meter LabVIEWbased DAQ pA – meter
New modes of operation – The Dual RILIS Prerequisite for dual operation: Temporal synchronization pulses of the two laser systems dye and Ti:Sa are exchangeable Mixed schemes 90 W Nd:YAG laser is available for non-resonant ionization in Ti:Sa only schemes Backup solution Highest efficiencies New elements Keep one dye set up for future, use Ti:Sa instead Unique for laser ion sources Reduction in down time
RILIS runs in 2012 ISOLDE RILIS SCHEDULE 2012 Ca Ca Ca Ca Cd Cd At Au Sm At Ca Ca Au Sm Sm Ca Ca Sm Cd Cd Cd Cd Dy Sm Be Po Sm Be Dy Po Po Be Be Po Mg Mg Mg Mg Dy At At Dy Mg Mg Be Mg Po Po Be Be Mg Be Mn Mn At At Ag Zn Zn Zn Zn Au Au Ag Be Be Mn Mn Cu Cu
RILIS highlights 2012 Ion beams of 13 elements produced with Dual-RILIS at ISOLDE 3060 hours of RILIS operation = 319 on-line shifts Development of narrow-band Ti:Sa laser - used for high resolution studies of Po, At, Fr, and Au isotopes Laser Ion Source and Trap: LIST Suppression of Fr isobars for study Po-217
RILIS/LARIS projects for LS1 • Extension of RILIS cabin • Enlarged entrance/storage and work area to maximize the useable laser laboratory space GENERAL RILIS DEVELOPMENTS • A dedicated, high power Nd:YVO laser for non resonant ionization • High beam quality industrial laser could significantly improve efficiency for many schemes. • RILIS machine protection system • Installation of a machine protection and monitoring system to reduce reliance on shift-based operation • Space stabilization of laser beams • Upgrade of existing commercial system to enable active stabilization of 3 beams and UV beams • Installation of a reference cell at RILIS • Improved motorization of Narrow-band TiSa • Ionization of refractory metals • Study of laser ionization in VADIS cavity • New and improved RILIS schemes for the Dual RILIS system • According to requests from ISLODE users: Ba, Te, Cr, Er, … SPECTROSCOPY and IONIZATION SCHEMES • GPS laser beam launch • Replacement of prisms by high-reflectivity dielectric mirrors will reduce the losses of laser power in the beam transport to GPS mass separator • HRS laser window • Extension tube for window mounting outside the 90o magnet will enable monitoring of window quality during operation and simplify its replacement
RILIS room extension Required by safety 28 m2 Existing laser room + SAS + Air ventilation + Emergency exit (?) 254 cm 320 cm Extended part (SAS) IS COOLER 6 m2 100 cm REX EBIS platform
Blaze laser test A multi-stage test of a Blaze 532-40-HE diode pumped Nd:YVO4 laser, supplied as a loan by LumeraLaser GmbH, has been performed on 17-18 December 2012. • 40W at 10 kHz • 17ns Pulse • Low Jitter • Gaussian beam • Much better transmission efficiency to ion source B. Marsh et al., Stability test of a high quality Nd:YVO industrial laser for the ISOLDE RILIS installation. CERN-ATS-Note-2013-007 TECH
Blaze laser versus RILIS lasers Due to the higher beam quality, the laser power that can be delivered through the 3 mm aperture at the reference point is 2.2 times higher than can be achieved with the Edgewave laser that is currently installed.
Test of Gaionization: Blaze versus EdgeWave For each power level of the Blaze laser, a considerable change in the telescope focusing was required to regain optimal efficiency. A likely cause of this effect is thermal lensing due to absorption of the beam at the quartz window of the mass separator. Power dependent thermal lensing in the beam transport optics is to be eliminated !
HRS laser window Periodic replacement is needed because of contamination of internal surface In the 90o magnet the window is mounted inside the magnet, a special tool is used to extract it, - very complicated operation Proposal: To make an extension tube to the HRS chamber for mounting the window outside magnet, as at GPS Easy to inspect, easy to replace
Machine protection/safety Dye Leak: Fire hazard; laser damage risk Up to 6 dye circulators each containing up to 3 L of ethanol flowing at 7 L/min. Pump laser control by Hyper-terminal commands and access to laser operator alert system (LABVIEW based) Action required: Stop pump laser, alert the laser operator. + Organic solvent detector (breathalyzer) + Micro-controller and data logger Dye flow interruption: Fire hazard; laser damage risk Up to 40 W pump beam focused on dye cell. Almost immediate dye cell damage if dye flow stops. Action required: Block pump beam to dye laser, alert the laser operator. Laser beam shutter Flip mirror/ beam dump assembly with controller Non invasive dye flow sensor (ULTRASONIC) Solution to be tested: + Micro-controller and data logger + Water leak: Equipment damage risk; electrical safety hazard Water cooling for Ti:Sa crystals. Water cooling network for each dye circulator. Action required: Stop pump lasers, alert the laser operator. Install water leak sensor cables on laser table and RILIS cabin floor Include sensor data logger in RILIS monitoring system
RILIS Machine Protection • The Ethanol based dye laser medium poses a possible fire hazard and a lack of dye flow can result in damage to the laser cells. Thus, an independently operable and reliable machine protection system is specified to be capable of: • Constant surveillance of criticalparameters, also publishedtonetwork • Triggering of safety shutters as well as initiating controlled shutdown • Sending alerts and status reports for operators via GSM text messages Under construction in STI-ECE Schematic RILIS Machine Protection System overview and operator phone.
Laser beam stabilization Commercial system adapted to RILIS conditions Piezo-actuators for fast beam displacement Stabilization of high and low frequency beam fluctuations Currently capable of stabilizing up to two visible or IR beams
Laser installation at new off-line separator Implementation plan for building 275 • Testing of new ionization schemes • Development of new approaches to laser ion sources • Study of laser – ion interaction in the RF-cooler
RILIS ion beams • Ion beams of 31 elements are produced at ISOLDE with RILIS Recent new beams: Sm, Pr, At, Ca Requested beam development
RILIS status monitoring Essential RILIS parameters are published to a Labview DSM. All values are accessible from the CERN technical network RILIS monitor display is published to a website for remote monitoring • Power • Wavelength • Proton current • Reference beam • images https://riliselements.web.cern.ch/riliselements/LASERS/
Remote Monitoring and Control System • Goals • Modular and flexible remote device monitoring and control • Operator support in complex “Dual RILIS” supervision • Self-reliant machine protection • Future prospect: On-call operation • Collaborative Data Acquisition ISOLDE Faraday Cups, ISOLTRAP MR-ToF data, Windmill alpha detector, … • Technology National Instruments LabVIEWand Shared Variable Engine, CERN technical network infrastructure By Ralf Rossel Monitoring Control Power Power Device Communi- cation RS-232 Ethernet USB Timing Wavelength Readout RS-232 USB Position Power over Ethernet RS-232 PoE Injector Ethernet RS-232 USB Monitoring Auxiliary Software Auxiliary Sensor Data NI Shared Variable Engine General Status Info & Control RILIS, VISTARS… ISOLDE Ion Beam Current (FESA readout) PSB Proton Beam Current (FESA readout) PSB TelegramSynchronization (JAPC readout) Cooling Units Status & Control Data Logging Wavelength Position Data Processing Device Communi- cation and Readout Timing Software Control Data Acquisition and Storage
Laser Ion Source and Trap (LIST) On-Line at ISOLDE Ionization and suppression of contaminants by LIST: LIST device: LIST assembly: Laser ionized 30Mg RILIS mode LIST mode Suppressed 26Na, 46K Ion repeller RF terminals • LIST was successfully tested with UCx-target -> No loss of performance over 5 days • Suppression of Na-, Al-, K-, Fr-, U-isotopes studied -> Suppression factors varied from 100 to 1000 • Laser ionization of radioactive Mg and Po in LIST Fr suppression and laser ionization of Po in LIST First ever LIST on-line physics result: hyperfine structure of 217Po
The Dual Etalon Narrow Linewidth TiSa Addition of a thick etalon to the TiSa cavity Remote dual etalon control, automatic optimization routine and feedback based frequency stabilization Reduction of line-width from >5 GHz <1GHz
Example of RILIS setup • Ni: Dye-Dye-TiSa Step 2 Step 3 Step 1 Higher power from TiSa for AIS transition 305 nm Dye SHG Ni 611 nm Dye fund 748 nm TiSafund
Example of RILIS setup • Ca: TiSa-Dye-Dye Step 3 Step 2 Step 1 Ca 423 nm TiSa SHG 586 nm Dye fund 654 nm Dye fund
Example of RILIS setup • Mg: Dye-Dye-YAG Step 1 Step 2 285 nm Dye SHG Mg 532 nm Nd:YAG SHG 553 nm Dye fund Only Dye scheme, TiSa is setting up for next run (Po)
Example of RILIS setup • Po: Dye-TiSa-YAG 256 nm Dye THG 532 nm Nd:YAG SHG 843 nm TiSafund Po
Example of RILIS setup • At: Dye-TiSa-YAG Step 3 Step 2 Step 1 Dye and TiSa exchangeable for Step 1 216 nm Dye THG 532 nm Nd:YAG SHG 795 nm TiSafund At Higher power from TiSa for Step 2
Example of RILIS setup • Au: TiSa-Dye-Dye Step 3 Step 2 Step 1 Au 674 nm Dye fund 268 nm TiSa THG 306 nm Dye SHG Higher power from TiSa for Step 1
RILIS operation in 1994-2012 3060 h lasers ON 319 on-line shifts Availability of two complementary laser systems (Dye and Ti:Sapphire) has ensured the increase of RILIS beam time in 2011-2012 Ion beams of 13 elements were produced with RILIS in 2012
RILIS operators: • 2 CERN stuff members: Bruce Marsh, Valentin Fedosseev • 2 CERN fellow: Sebastian Rothe, Tom Day Goodacre (contracts started 1.10.2012) • 1 PhD student: Daniel Fink • ISOLDE Users (2 in average): Maxim Seliverstov, Dmitry Fedorov, Nobuaki Imai, Pavel Molkanov, ... At present RILIS operation is organized in 8-hours shifts: 4 persons on shifts + 1 person on-call Regular breaks in laser operation are needed for rest: Not more than 3 weeks of work without free days.
Gold Isotopes Faraday Cup MR-TOF Windmill COUNTS 1st transition is difficult with dye laser (UV pump beam required) NB-TiSa was therefore advantageous: scanning stability with 3rd harmonic was demonstrated Alpha energy, keV MR-TOF, windmill and FC were used Beam time was extremely limited !
Astatine Isotopes: scans on both steps Si Annular Si Faraday Cup MR-TOF Windmill 197At beam NB - TiSa C-foils 20 mg/cm2 NB - Dye laser ISOLDE Faraday cup Extensive Ionization scheme development was required