ICIS2015 in NY Y.HIGURASHI Y. Higurashi (RIKEN Nishina center) 1.Introduction RIKEN RIBF and RIKEN 28GHz SC-ECRIS 2.Emittance measurements 1.4D emittance of U D emittance of He D emittance of U 35+ (lower B ext B ext ~1.45T) 3.Conclusion Emittance measurement for RIKEN 28GHz SC-ECRIS

ICIS2015 in NY Y.HIGURASHI 10.8MeV/u10.8MeV/u 50MeV/u 345MeV/u 0.6MeV/u 3.2keV/u He gas stripper Be stripper Efficiency ~15%Efficiency ~30%Efficiency ~4.5% U beam U,Xe beam O, Ca, Kr beam Due to low transmission efficiency ( ~4.5%), we surely need the intense beam production form the ECRIS Construction of the New SC-ECRIS(2009~ ) Due to low transmission efficiency ( ~4.5%), we surely need the intense beam production form the ECRIS Construction of the New SC-ECRIS(2009~ )

ICIS2015 in NY Y.HIGURASHI 345MeV/u 238 U, 124 Xe New injector system ~0.6MeV/u 238 U 35+, 124 Xe 19+ 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+ )

ICIS2015 in NY Y.HIGURASHI The RIKEN SC-ECRIS can be operated at flexible axial field distributions with six solenoid coils It is possible to change the gradient of the magnetic field strength and the surface size of the ECR zone. The RIKEN 28GHz SC ECRIS produced ~180e  A of U 35+, ~225 e  A of U 33+ with the sputtering method at the injected RF power of ~2.5kW (28GHz+18GHz). T. Nakagawa et al, Rev. Sci. Instrum. 81, 02A320(2010) G.Alton and D. Smithe, Rev. Sci. Instrum. 65, 775(1994 ).

ICIS2015 in NY Y.HIGURASHI Plasma chamber Biased disc U-rod Support rod(water cooled) U 35+ ion beam production with sputtering method About High Temperature Oven will be presented by J. Ohnishi et al ThuPS06

ICIS2015 in NY Y.HIGURASHI Analyzing magnet The beam was analyzed by the analyzing magnet which is same structure as that made in LBL. It has special shaped poles to apply sextupole correction in both the horizontal and vertical plane. The bending radius, vertical gap in the plasma chamber were 51cm and 14cm, respectively. The maximum rigidity was Tm.. M.A. Leitner, et al, Proceedings of the 15th International Workshop on ECR Ion Sources, ECRIS02,

ICIS2015 in NY Y.HIGURASHI LEBT and beam profiling monitor system Emittance slit Figure shows the low energy beam transport (LEBT) line from the ion source to beam profiling monitor system. The extracted beam was focused by the solenoid coil (beam focusing solenoid coil) The beam was analyzed by the analyzing magnet The emittance was measured using the emittance monitor, which consists of two movable thin slits (H-and V-emittance) and scanning wires (beam profile monitor). We also installed the beam slit and Faraday cup in the vacuum chamber of the beam monitoring system.

ICIS2015 in NY Y.HIGURASHI Measurement of 2D and 4D emittance 2D emittance measurement 4D emittance measurement Spectrum ( profiling monitor H-axis)

ICIS2015 in NY Y.HIGURASHI 4D beam matrix and 4D emittance

ICIS2015 in NY Y.HIGURASHI 2D emittance Threshold The four rms emittance H 300  mm*mrad V 162  mm*mrad U μA

ICIS2015 in NY Y.HIGURASHI Beam trajectory in LEBT From the experimental results of the full four-dimensional transverse phase-space distribution of highly charged U ion beam including correlations between the horizontal and vertical planes for the beam axis, we can calculate the 4D emittance on the upstream side of the analyzing magnet, if we calculate the beam trajectory in the analyzing magnet precisely. For calculating the beam trajectory, we used the code OPERA 3D.

ICIS2015 in NY Y.HIGURASHI B ext ~1.75T U μA I drain 4.4mA B ext 1.75T B ext ~1.75T U μA I drain 4.4mA B ext 1.75T Measured position (Downstream) OPERA 3D Upstream (Ion source side)

ICIS2015 in NY Y.HIGURASHI Upstream (Ion source side) Measured position (Downstream) B ext ~1.75T U μA I drain 4.4mA B ext 1.75T B ext ~1.75T U μA I drain 4.4mA B ext 1.75T EM Slit Measurement OPERA calculation HV4DHV  mm mradmm 2 mrad 2  mm mradmm 2 mrad 2

ICIS2015 in NY Y.HIGURASHI He μA I drain 11.1mA B inj 3.11T B min 0.62T B ext 1.79T B r 1.87T He μA I drain 11.1mA B inj 3.11T B min 0.62T B ext 1.79T B r 1.87T Upstream (Ion source side) Measured position (Downstream)

ICIS2015 in NY Y.HIGURASHI Upstream (Ion source side) Measured position (Downstream) He μA I drain 11.1mA B inj 3.11T B min 0.62T B ext 1.79T B r 1.87T He μA I drain 11.1mA B inj 3.11T B min 0.62T B ext 1.79T B r 1.87T EM Slit Measurement OPERA calculation HV4DHV  mm mradmm 2 mrad 2  mm mradmm 2 mrad 2

ICIS2015 in NY Y.HIGURASHI B ext ~1.42T U μA I drain 3.3mA B ext ~1.42T U μA I drain 3.3mA Upstream (Ion source side) Measured position (Downstream)

ICIS2015 in NY Y.HIGURASHI Upstream (Ion source side) Measured position (Downstream) B ext ~1.42T U μA I drain 3.3mA B ext ~1.42T U μA I drain 3.3mA EM Slit Measurement OPERA calculation HV4DHV  mm mradmm 2 mrad 2  mm mradmm 2 mrad 2

ICIS2015 in NY Y.HIGURASHI EM Slit measurement OPERA calculation HV4DHV EM Slit measurement OPERA calculation HV4DHV B ext ~1.75T U μA I drain 4.4mA B ext 1.75T B ext ~1.75T U μA I drain 4.4mA B ext 1.75T B ext ~1.42T U μA I drain 3.3mA B ext ~1.42T U μA I drain 3.3mA

ICIS2015 in NY Y.HIGURASHI Summary We measured the 4D emittance of U 35+ and He 1+ ion beams and calculated the 4D emittance on the upstream side of the analyzing magnet. We observed that the aberration of ion optics strongly affects the emittance for He 1+ ion beam, which is mainly due to the beam size in the analyzing magnet. To compare the 4D emittance with B ext ~1.42T and that with B ext ~1.75T, we obtained the result that the emittance with lower B ext is larger than that with higher B ext, even when we remove the effect of aberration of the ion optics. To clarify this results, we need further investigation.

ICIS2015 in NY Y.HIGURASHI Bext ~1.42 U35+ 40μA EM slit 測定 OPERA で BM を通した後 EM Slit mesurement OPERA calcuration HV4DHV BM 入り口 BM 出 口

ICIS2015 in NY Y.HIGURASHI He+ 2600μA EM slit 測定 OPERA で BM を通した後 EM Slit mesurement OPERA calcuration HV4DHV BM 入り口 BM 出 口

ICIS2015 in NY Y.HIGURASHI Bext ~1.75 U μA EM slit 測定 OPERA で BM を通した後 EM Slit mesurement OPERA calcuration HV4DHV BM 入り口 BM 出 口

ICIS2015 in NY Y.HIGURASHI Intense U beam production with sputtering method ~100e  A U 35+ for long term operation 1. Minimization of the consumption rate we need long term continuous beam production (1~2 montns) for RIBF experiment. To meet this requirement, even if we can install 10gr of metal U, the consumption rate should be lower than ~7 mg/h. 2. Minimization of the emittance To accelerate intense beam of heavy ions (>1p  A) at high energy (>100MeV/u), the emittance should be sufficiently smaller than the acceptance of the accelerator for avoiding the damage by the beam loss in the accelerator. 3. Minimization of the X-ray heat load For SC-ECRIS with small refrigerators (Total cooling power of several W at 4.2K), the beam intensity may be limited by the large amount of X- ray heat load in the cryostat. ~180e  A of U 35+ for short term ~ ~ Increase the beam intensity for RIBF

ICIS2015 in NY Y.HIGURASHI M. Nishida et al, PASJ 2015,FSP003 28GHz SC-ECRIS RILAC RILAC II AVF cyclotron SRC IRC fRC RRC ~345MeV/u