Recent progress of RIKEN 28GHz SC-ECRIS for RIBF T. Nakagawa (RIKEN) 1.Introduction RIKEN Radio isotope factory project 2.RIKEN 28GHz SC-ECRIS Structure(Sc-coils, cryostat) 3.Recent results (uranium ion beam) Effect of Al chamber Biased disc effect(28GHz) operation for long term (>1month)(stability, emittance) first result with high temperature oven two frequencies heating(18+28GHz) 4.Summary 5.Next step RISP workshop, May19-21, 2013, Daejeon, Korea

18GHz ECRIS RILAC (RIken Linear ACcelerator) fRCfRC RRCRRC IRCIRC SRCSRC RIKEN RIBF 28GHz SC-ECRIS RILAC II(RIken Linear ACcelerator) RISP workshop, May19-21, 2013, Daejeon, Korea

New injector system ~0.6MeV/u 238 U 35+, 124 Xe MeV/u 238 U, 124 Xe Extraction voltage 22kV m/q <6.8 ( 238 U 35+, 124 Xe 19+ ) Extraction voltage 22kV m/q <6.8 ( 238 U 35+, 124 Xe 19+ ) New Injector (RILAC II) RISP workshop, May19-21, 2013, Daejeon, Korea

Recent progress of RIKEN 28GHz SC-ECRIS for RIBF T. Nakagawa (RIKEN) RISP workshop, May19-21, 2013, Daejeon, Korea 1.Introduction RIKEN Radio isotope factory project 2.RIKEN 28GHz SC-ECRIS Structure(Sc-coils, cryostat) 3.Recent results (uranium ion beam) Effect of Al chamber Biased disc effect(28GHz) operation for long term (>1month)(stability, emittance) first result with high temperature oven two frequencies heating(18+28GHz) 4.Summary 5.Next step

RIKEN 28GHz SC-ECRIS I) SC-coils II) Cryostat III) Plasma chamber IV) Gyrotron V) LEBT(Analyzing magnet, solenoid coil, FC, profile monitor, emittance monitor, beam slit) RISP workshop, May19-21, 2013, Daejeon, Korea

Magnetic fieldB inj ~4TB ext ~2TB r ~2T (High B mode)(plasma confinement) B min <1T (choose the optimum field gradient) ECR zone size as large as possible Chamber sizeDiameter 15cm (comparison between RIKEN 18 GHz and VENUS, SCRAL) Length50cm(Long confinement time) Microwave28GHz Power10kW ( 1kW/L)(High power density) ChamberMovable biased disc (matching between frequency and chamber size) Magnetic fieldB inj ~4TB ext ~2TB r ~2T (High B mode)(plasma confinement) B min <1T (choose the optimum field gradient) ECR zone size as large as possible Chamber sizeDiameter 15cm (comparison between RIKEN 18 GHz and VENUS, SCRAL) Length50cm(Long confinement time) Microwave28GHz Power10kW ( 1kW/L)(High power density) ChamberMovable biased disc (matching between frequency and chamber size) RISP workshop, May19-21, 2013, Daejeon, Korea

SC-coils I RISP workshop, May19-21, 2013, Daejeon, Korea T. Nakagawa et al, Rev. Sci. Instrum.81 (2010) 02A320. “Flat B min ” G. D. Alton and D. N. Smithe, Rev. Sci. Instrum. 65 (1994)775

Cryostat I GM refrig. 35W(45K), 6.3W(10K) GM. Refrig. 50W(43K), 1.0W(4.2K) )(GM-JT refrig.) CG310SC(SUMITOMO)(GM-JT refrig.) Cooling capacity Electric power consump.5.1/6.1kW(50/60Hz) Electric powerAC200V 3 phase Weight~220kgr Dimension700Wx520Dx1095H RISP workshop, May19-21, 2013, Daejeon, Korea

Cooling power (4.2K)2GM-JT ~7.3W 1GM ~1.0W Total ~8.3W Without plasmacooling power ~8W GM-JT cooling power Heat load Cryostat II RISP workshop, May19-21, 2013, Daejeon, Korea

Recent progress of RIKEN 28GHz SC-ECRIS for RIBF T. Nakagawa (RIKEN) RISP workshop, May19-21, 2013, Daejeon, Korea 1.Introduction RIKEN Radio isotope factory project 2.RIKEN 28GHz SC-ECRIS Structure(Sc-coils, cryostat) 3.Recent results (uranium ion beam) Effect of Al chamber Biased disc effect(28GHz) operation for long term (>1month)(stability, emittance) first result with high temperature oven two frequencies heating(18+28GHz) 4.Summary 5.Next step

Plasma chamber Extraction electrode Plasma electrode Sc-solenoide coils Biased disc U rod ECR zone U-rod Support rod(water cooled) Uranium ion beam production (sputtering method) B inj ~3.2T, B min ~0.6T, B ext ~1.9T B r ~1.9T B inj ~3.2T, B min ~0.6T, B ext ~1.9T B r ~1.9T RISP workshop, May19-21, 2013, Daejeon, Korea Advantage install large amount of U metal (>10gr)long term operation without break Disadvantage weak beam intensity ( compared to oven method)

RIKEN10GHz ECRIS RIKEN18GHz ECRIS T. Nakagawa et al, JJAP 35(1996)4077 T. Nakagawa, JJAP 30(1991)L930 Ar 10~16+ Al 2 O 3 coating or Al chamber RIKEN 28GHz SC-ECRIS Plasma chamber surface effect I RISP workshop, May19-21, 2013, Daejeon, Korea

Plasma chamber surface effect II RISP workshop, May19-21, 2013, Daejeon, Korea Al chamber ( lower beam intensity of O ions)

Ar 10~16+ Al 2 O 3 coating or Al chamber RIKEN 28GHz SC-ECRIS U 35+ ion beam RIKEN 28GHz SC-ECRIS U 35+ ion beam Plasma chamber surface effect III RISP workshop, May19-21, 2013, Daejeon, Korea

U 35+ V saturation ~-300V V saturation ~-80V Mean charge state ~36+ Mean charge state ~33+ Ion source was tuned to produce U 35+ ion beam Biased disc voltage effect RISP workshop, May19-21, 2013, Daejeon, Korea Bias disc voltage (kV)

RISP workshop, May19-21, 2013, Daejeon, Korea Disc position Gross feature

Fine structure L pp =1~2mm Biased disc position effect Disc position RISP workshop, May19-21, 2013, Daejeon, Korea Plasma chamber( multi-mode cavity) biased disc position? Microwave frequency, wave length Plasma chamber( multi-mode cavity) biased disc position? Microwave frequency, wave length

Sputtering voltage effect Beam intensity (U 35+ ) Sputtering current Charge distribution RISP workshop, May19-21, 2013, Daejeon, Korea

Charge distributions of highly charged U ions Tuned for 33+ production Tuned for 35+ production Tuned for 41+ production RISP workshop, May19-21, 2013, Daejeon, Korea

U 35+ ~180e  A U 42+ ~18e  A U 33+ ~230e  A RISP workshop, May19-21, 2013, Daejeon, Korea

VENUS 28GHz RIKEN SC-ECRIS 28GHz High energy x-ray (>several 100keV) plasmacryostat D. Leitner et al, RSI 79(79) Y. Higurashi et al, accepted for publication to RSI X-ray heat load I RISP workshop, May19-21, 2013, Daejeon, Korea

X-ray heat load III Lager zone size and steeper field gradient gives lower X-ray heat load X-ray heat load using Al-chamber is lower than that using SS-chamber RISP workshop, May19-21, 2013, Daejeon, Korea

Bo : axial magnetic field q: charge state M: mass Bo 18GHz ~1.2T 28GHz ~1.8T Cal: same q/M same emittance : higher Bolarger emittance 18GHz 28GHz Emittance measurements I RISP workshop, May19-21, 2013, Daejeon, Korea

Emittance measurements II RF power dependence Emittance during the beam time (for two months) Emittance was strongly dependent on the ion source condition (0.06 ~0.1  mm mrad) Emittance was strongly dependent on the ion source condition (0.06 ~0.1  mm mrad) RISP workshop, May19-21, 2013, Daejeon, Korea

Beam production for beam time (long term operation) U35+ beam production with sputtering method RF power~ 1.3kW average beam intensity ~86 e  A U rod~15gr consumption rate ~4 mg/h U35+ beam production with sputtering method RF power~ 1.3kW average beam intensity ~86 e  A U rod~15gr consumption rate ~4 mg/h RISP workshop, May19-21, 2013, Daejeon, Korea

Beam production for beam time (long term operation) Extraction current ~3.7mA ~3.4mA ~3mm shifted Beam profile Decrease of beam intensity from ring cyclotron Increase the temperature of electric deflector channel(EDC) of cyclotron EDC may be damaged by the intense beam) Decrease of beam intensity from ring cyclotron Increase the temperature of electric deflector channel(EDC) of cyclotron EDC may be damaged by the intense beam) Time RISP workshop, May19-21, 2013, Daejeon, Korea

High temperature oven 18GHz 28GHz Movable biased disc High temp oven Cooling water channel RISP workshop, May19-21, 2013, Daejeon, Korea

High temp. oven Current and temperature of the oven RISP workshop, May19-21, 2013, Daejeon, Korea Ansys simulation current 429A max. temp. 2205K

First result with high temp. oven 1. beam intensity of U 35+ ~170e  A Oven current 445A(~1900deg.) 2. We need 2days for production of the beam (1day for evacuation of the chamber, 1day for ion production) 3. Check the life time of the oven and consumption rate of the material(UO 2 ) Tuned for production of U 33+ ion RISP workshop, May19-21, 2013, Daejeon, Korea

28GHz +18GHz(500W) 28GHz 18GHz 28GHz Injection of Two frequencies(18+28GHz) RISP workshop, May19-21, 2013, Daejeon, Korea

Two frequencies Beam intensity as a function of B min Beam intensity as a RF power (18GHz) RISP workshop, May19-21, 2013, Daejeon, Korea

Recent progress of RIKEN 28GHz SC-ECRIS for RIBF T. Nakagawa (RIKEN) RISP workshop, May19-21, 2013, Daejeon, Korea 1.Introduction RIKEN Radio isotope factory project 2.RIKEN 28GHz SC-ECRIS Structure(Sc-coils, cryostat) 3.Recent results (uranium ion beam) Effect of Al chamber Biased disc effect(28GHz) operation for long term (>1month)(stability, emittance) first result with high temperature oven two frequencies heating(18+28GHz) 4.Summary 5.Next step

Summary 1.Beam intensity of highly charged U ion beams (Al chamber) Sputtering method +single RF (28GHz) at 3~4kW injection U 35+ ~180e  A U 33+ ~230e  A (U 33+, 34+ ~440e  A) U 42+ ~18e  A 2. The intense beam of U 35+ ion was produced for RIBF experiment longer than one month without break 3. The emittance of the U 35+ ion beam ~0.06  mm mrad (normalized 1 rms)( it is strongly dependent on the ion source condition 0.06~0.1  mm mrad) 4. High temperature oven successfully started to produce U 35+ ion beam with high temperature oven 5. Two frequencies we observed the enhancement of the highly charged U ion beam using two frequency(18+28GHz) 1.Beam intensity of highly charged U ion beams (Al chamber) Sputtering method +single RF (28GHz) at 3~4kW injection U 35+ ~180e  A U 33+ ~230e  A (U 33+, 34+ ~440e  A) U 42+ ~18e  A 2. The intense beam of U 35+ ion was produced for RIBF experiment longer than one month without break 3. The emittance of the U 35+ ion beam ~0.06  mm mrad (normalized 1 rms)( it is strongly dependent on the ion source condition 0.06~0.1  mm mrad) 4. High temperature oven successfully started to produce U 35+ ion beam with high temperature oven 5. Two frequencies we observed the enhancement of the highly charged U ion beam using two frequency(18+28GHz) RISP workshop, May19-21, 2013, Daejeon, Korea

1.Optimizing the magnetic field distribution 2.Two frequency heating (28GHz+18GHz) 3.Minimizing the consumption rate of the material sputtering method4mg/h Total consumption ~6g/2months consumption rate for oven method? 4.Stabilizing the beam intensity (minimizing the damage of the accelerator) ( emittance slit?) 5. Minimalizing the X-ray heat load 1.Optimizing the magnetic field distribution 2.Two frequency heating (28GHz+18GHz) 3.Minimizing the consumption rate of the material sputtering method4mg/h Total consumption ~6g/2months consumption rate for oven method? 4.Stabilizing the beam intensity (minimizing the damage of the accelerator) ( emittance slit?) 5. Minimalizing the X-ray heat load Next step RISP workshop, May19-21, 2013, Daejeon, Korea