Beam spot temperature monitoring on production target of BigRIPS separator

Transcription

1 Beam spot temperature monitoring on production target of BigRIPS separator Atsushi Yoshida & Yoshiyuki Yanagisawa (BigRIPS team, RIKEN) Target system, targets in operation Temperature monitoring under high-radiation environment Recent temperature data & comparison with simulations (preliminary) RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 1

2 RIBF (RI-beam factory) Linac frc RRC SRC Energy (MeV/nucleon) RRC with frc (SRC) 350 MeV/nucleon 88+ (8Tm) with frc (IRC) 1 p μa (goal) H O Ar Kr Xe Bi Atomic Mass IRC BigRIPS In-flight RI-beam separator Production Target (Fragmentation reaction) (Max. beam power) 238 beam 350MeV/A, 1pμA : 83kW beam spot size 1mm (FWHM), on Be,W ~1g/cm 2 ΔE= 24kWatt 31GW/m 2 : on the surface of the target 5.5kW/mm 3 (5.5MW/cm 3 ) : inside the target RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 2

3 Schematic view of rotating disk target with water-cooling Rotating disk target unit for BigRIPS double-piped shaft water-cooled disk Air-press. Box Target vacuum chamber ( Components ) Rotating solid target disk to dissipate the heat of the beam spot Water-cooled disk to remove heat from the target disk Rotating actuator & motor to rotate the disks in high speed ~ 500rpm Double-piped shaft & rotary joint to introduce cooling water into the rotating disks. RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 3

4 Core unit : Removable target flange unit slide Rot. Disk target Removable target flange unit weight ~ 500 kg Ladder shaped Fixed target slide Rotating disk target unit RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 4

5 Target disks Be disk Diameter : 300 mm (Thickness : max 20mm) Be disk mounted on a disk unit min ~ max 0rpm Be tapered targets Step shaped edge 20,15,10 mm thick for N, Ca, Ar beams 10, 7, 5 mm thick for Kr, Xe, beams Disk materials : Be, W are ready for exp. Diameter : ~ 20 mm Thickness : 1 ~ 20, ~ 60 mm RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 5

6 Target list used for experiments Prima ry beam Targets used Ta rget used for intense beam Date M.T. Beam Imax Power for the experiment d:thick,r:range Energy loss period [MeV/A] [pna] [kw] Material,Thick.[mm] shape d[mm] d/r [GeV] [kw] Mar,07 2wk 86 Kr 345 ~3 0.1 Be2, 12 Be Fixed Mar,07 2wk Be2, 5 Pb1.5 Pb Fixed May,07 3wk Be2, 5, 7 Pb1.5 Pb Fixed Jun,07 2wk Be0.1, 5, 7 Pb1.5 Be Fixed Nov,08 2wk Be3, 5, Pb 1+Al Pb Fixed Dec,08 2.5wk 48 Ca Be5, 10, 15, 20 Be Disk Mar,09 1wk 14 N Be12, 20 Be Fixed Ma y,09 2wk 14 N Be20 Be Fixed Nov,09 3wk Be3, 5, Be1.2+Al Be Fixed Dec,09 1wk 48 Ca Be10, 15, 20, 40 Be Disk Ma y,10 4wk 48 Ca Be10, 15, W2.1 Be Disk W Disk Jun,10 1.5wk 18 O Be40, 60 Be Fixed Be Fixed Goal: 238 beam 350MeV/u, 1pμA, Power = 83kW ΔE= 24kW still far from the goal RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 6

7 Beam Spot Temp [C] Target : Be Beam Spot radi : 0.5mm Water Cool radi : 5.0mm Xe Kr Ar Ne O C Tmp(Be) =1278C d/r Fixed target Primary Beam [pua] Beam spot monitoring * Estimation for beam spot temperature * It should be check experimentally from early stage. Stability of target should be monitored during exp. develop beam spot temperature monitors * Difficulties temp. measurement in vacuum & rotating Infra-red thermometer under high-radiation environment telescope + mirrors, fiber optics Target thickness Beam 350MeV/A Xe Kr Ar Ne O C [kw/1pμa] Rotating disk target Beam Spot Temp [C] Beam : 350A.MeV --> Target : Be Fixed Target Ref.) NIM A521(2004)65-71, INTDS conf. 2002, ANL Fragment separator Expert meeting, 2004 GSI, 2006 Riken Riken Acc.Prog.Rep. 41(2008)high-light vii. ANSYS (FEM code) simulation Fixed target Rotating Disk Tmp(Be) =1278C gain x10 Beam axis Fixing plate ( aluminum ) Target plate ( carbon ) Cooling plate ( aluminum ) Cooling water ( 25 ) Rotating Disk Target Fixed vs. Rotating disk target Primary Beam [pua] 1cm 1cm disk rotation RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 7

8 View port for beam spot monitoring upper view Target chamber (1) Fiber Beam (1) (2) (3) (2) CCD CCD (3) IR, Telescope Beam nit-1 ( Pillow seal ) STQ1 magnet (3) nit-2 CCD Alignment table Pump unit side view RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 8

9 CCD camera : Radiation damage CCD port (2) is used for checking proper motions of targets mechanics Beam CCD CCD 1m become blind 05/14 10h Exp. start 5/18 17h 5/19 15h 5/21 14h 5/24 10h 5/25 11h Beam Time : /14 06/11 48 Ca A.MeV max ~ 300pnA Primary beam tuning Experiments start Secondary beam tuning for RI beam production start 1day 2day 3day 7day 10day ~ ~ ~ End : 27day RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 9

10 Beam spot temperature monitors Beam spot CCD & Thermo viewer ( former location) Dose rate (calc) Fiber Sensor ~1μSv/h Laser pointer CCD camera TVS-8502 IR monitor ~1mSv/h Distance ~35m Visible Light View I.R. Light View Distance ~11m Target Beam Viewer : Desmarquest Mirror Fiber scope Temperature monitor 84Kr 345A.MeV 3pnA --> Be 12mm (calc.) Beam: 84Kr 350A.MeV 1pμA Beam Loss :F0=30%,D1=60%,F1=1.6% CCD ~10Sv/h RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 10

11 IR Fiber Scope IR Fiber Scope is used for beam spot temperature monitoring during whole exp. period Detector & Controller IR-FAQIX ~ 1 InGaAs(1.55) /InGaAs(1.35μm) Chino (Japan) IR-FAIX ~ 500 InGaAs(1.55μm) Lens unit Sapphire view port & Lenz unit mounted on the Target chamber φ16 x L 116 mm object distance ~1120mm φ5mm Fiber switch connection measuring position check using Laser spot indicator 40+2m long Quarts 400μm dia. Laser spot indicator measuring area ~ φ5mm IR Sensor & Controller units placed at 40m from the target actual beam spot ~ φ1mm during experiments measure an average temp. in a circle of 5mm dia. on an object placed at 1120mm from the lens unit RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 11

12 IR Fiber Scope IR sensor output signal (measured) 1.E+02 Temp. calibration (ε=1.00) 750 Fiber Scope Temp. [C] /25 18:00 18 O A.MeV Be 60mm (taper shape) 06/26 06:00 06/26 18:00 Beam spot temperature measured IR-FAIX43 ( 200 ~ 500 ) 06/27 06:00 Beam Current 06/27 18:00 [ arb. nit ] CHINO RawData 1.E+01 1.E+00 Light=OFF 1.35um Light=OFF 1.55um Light=ON 1.35um Light=ON 1.55um Light=OFF Light=ON Room light ON CHINO Temp [C] 1.E-01 Room light OFF E Heater [C] 500 IR-FAQIX06 (500 ~ 1 ) InGaAs(1.55)/InGaAs(1.35μm) RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 12

13 IR Thermo Viewer TVS-8502, Avio (Japan) + TVL-85626A telescope lens InSbFPA 256x256 array (3.5 ~ 4.1&4.5 ~ 5.1μm twin peak) Stirling cooler 40 ~ 0 (~ 2000 ND filter) Object 11m distance, ~ 30x30mm Image 256x236 dots, 14bit Frame rate 1/120sec, IEEE1394 (1/30sec) Lens : φ168mm, F4.0, f=626mm, Ge & Si Visible Zoom lens CCD camera I.R. Telescope lens TVS-8502 Spot check Laser pointer + focus lens Mirror φ150mm, Al-coating surf. smoothness < 20μm reflectivity > 95% for 3 ~ 5μm RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 13

14 IR Thermo Viewer : Radiation shield improved mirror 3 Telescope + CCD Target chamber Total 15m shielding box thermo viewer through sapphire view port 2.5 m along access tunnel horizontal 8.5 m make a hole through the ceiling vertical 2 m radiation level ( 48Ca pna ) γ 27μSv/h n-slow 20μ n-fast 530μ in shielding box γ 10μSv/h moved here! ~10μSv/h mirror - 1 mirror 2 former location ~1mSv/h RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 14

15 Temperature calibration using heater In order to reduce an ambiguity of emissivity (ε ) on target surface, the thermo viewer was calibrated using a heater unit in vacuum. Calibration data ( set ε=1.0 ) heater wire (front side view) Be plate hole for TC put W foil 0.1mm Black paint ε=0.94 W side Avio : measured temperature [C] Heater Calibration (AvioRange -40 ~ 150 ) 1Be center 2Be shine 3Be black 4Be black 5W shine 6W black 7W black if ε= black paint 56 2 Be 1 W 5 ε(be)calib. =0.10~ TC Be side Heater Temperature [C] R31_300C-Loff-R40_ jpg during experiment ( set ε=1.0 ), also for Be: use 1 Be curve for W: use 5 W curve RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 15

16 Fixed targets used for 48 Ca beam : 345 A.MeV max 300pnA Be10mm for 18 O beam : 345 A.MeV max 400pnA Be40mm before exp. beam spot ~φ2mm Thermo seal >50C, <C after exp. Be40mm Geometry (ANSYS modeling) thick 20mm beam spot ~φ3mm Thermo seal >C, <125C Fix plate Al t 5mm Be target φ22 taper shape Holder R13.5mm Water way 5x4mm RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 16

17 Fixed target ; temperature data magnified view G1: Beam Spot G2: Al plate G O 8+ beam : 345 A.MeV 438pnA (3500enA) Be 40mm thick (taper shape) O R002: Be40Tp 438pnA ini_temp=25c G1:exp G2 R002_Be40Tp-Rng150c-G enA-Loff G1 G2 G1 G2 whole view Temp. (non-calibrated) Beam Spot [C] G1: simulation Transient analysis G2:exp Static analysis Thermo Seal : ~125C BeamSpot BmSpt-ANSYS BmSpt-AnsStatic AlumPlate AlPlt-Ansys AlPlt-AnsStatic Time [sec] (( ANSYS params )) water way = 3kW/(m2.K) target taper= kw/(m2.k) Water Temp = 25C fix Therm. Coduct. Be = 180W/(m.K) fix Al = 239W/(m.K) fix Radiation = off Beam Spot = φ3.0mm fwhm G2: simulation (( Cooling water data )) Water Flow = 5.4L/min Flow speed = 0.45m/s Water Press = in 0.43 out 0.21 MPa Water Temp = in 25.5C, dt~1.0c = 378Watt Heat = de:1.35gev*438pna=591.3watt RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 17

18 Fixed target ; temperature data G1: Beam Spot G2: Al plate G1 G2 R015_Be10Tp-G enA-BmOff-On-Loff G1 Temp. (non-calibrated) 48 Ca 20+ beam : 345 A.MeV 200pnA (4000enA) Be 10mm thick (taper shape) Beam Spot [C] Ca R015: Be10Tp 200pnA ini_temp=50c G1:exp BeamSpot BmSpt-ANSYS BmSpt-AnsStatic AlumPlate AlPlt-Ansys AlPlt-AnsStatic G1: simulation G2 G G2:exp Thermo Seal : 50~105C G2: simulation Time [sec] G2 (( ANSYS params )) water way = 3kW/(m2.K) target taper= kw/(m2.k) Water Temp = 25C fix Therm. Coduct. Be = 180W/(m.K) fix Al = 239W/(m.K) fix Radiation = off Beam Spot = φ2.0mm fwhm (( Cooling water data )) Water Flow = 1.8L/min Flow speed = 0.15m/s Water Press = in 0.35 out 0.28 MPa Water Temp = in 25.5C, dt~2.0c = 252Watt Heat = de:2.06gev*200pna=412.4watt RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 18

19 Beam Spot Temp. [C] Beam : 18O 345A.MeV Spot sizeφ3mm Target : Be 40mm (Taper) Exp C.Trg25 C.Wtr25C A.Trg25C y = x A.Wtr25C A.Fit A.Ht A.Hw,Ht ExpFit Discrepancy at the Beam Off temperature Calibration wrong? or other I beam reasons [pua]? Fixed target data ; compare with simulations Thermal conductivity = ON A.Hw,Ht A.Fit Water way : Hw = 30k 80k W /(m2.k) Taregt side : Ht = k 50k Be 40mm Taper side Thermal contact was good / bad? (( Cylindrical model )) analytical model Tr2 [ ] r 2[mm] Beam Qin[W] Tr1[ ] r 1[mm] Target Ltg[mm] Tr1 : Beam Spot Temp. = Tr2 + Qin*Ln(r2/r1) /(2πκLtg ) Qin = Ibeam * de de / Ltg check ANSYS vs Cyl.Model (( ANSYS model )) 3D model Beam Spot Temp. [C] Water way Beam : 48Ca 345A.MeV φ2mm Target : Be 10mm (Taper) y = x AHt Hw = 25Cfix Ht = k Therm. cond. = ON check ANSYS vs Cyl.Model Exp C.Trg25 C.Wtr25C A.Trg25C A.Wtr25C A.Fit A.Ht A.Hw,Ht E Fit I beam [pua] Be 10mm, simple tapered shape, should correspond well with cylindrical model. Thermal convection at Water way is too good? Thermal contact ( thermal convection ) 10kW/(m2.K) CP heat-sink RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 19

20 Rotating disk target ; temperature data R047: Be15mm Disk rpm 3300enA G1: Beam Spot G Beam Spot [C] Ca + Be 15 Disk R47 rpm 165pnA R47_rpm min. rotation speed : rpm Time [sec] R024: W 2.1mm Disk 150rpm 3700enA Be disk ; we cold not observe temp. rise. ANSYS calculation for disk experimental data has not done yet. ( sorry ) 50.0 G Beam Spot [C] Ca + W2.1Disk R24 150rpm 185pnA R24_150rpm Time [sec] W disk ; we could observed, but.. Beam spot temperature shows vibration. RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 20

21 Rotating disk target ; temperature data Beam Spot [C] Beam Spot [C] Ca + W2.1Disk R24 150rpm 185pnA R23 rpm 190pnA rpm 150rpm Some component of different temperature? Time [sec] 48Ca + W2.1Disk R24 150rpm 185pnA R23 rpm 190pnA R24_150rpm R23_rpm Time [sec] Rot. Speed Temp. Vibration [Hz] Flame rate = 1/10sec The vibration synchronize rpm rps points sec [Hz] with its rotation speed Because of using high speed thermo viewer, I could face a real cooling effect of my water-cooling target disk. Beam Spot Temp. [C] Changing disk rotation speed 48Ca -> W2.1mm Disk Exp_W2.1Dk-rpm Exp_W2.1Dk-150rpm Exp_W2.1Dk-300rpm I beam [pua] Water way a slit decrease of temperature observed inlet outlet 8 screws to fix target disk Inner structure of the water-cooled disk RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 21

22 00 Target : Be Beam 345 MeV/A Beam Spot radi : 1mm Water Cool radi : 13.5mm ( Fixed target ) Beam Target material : Be vs. W ( Disk target ) Xe 00 ( Fixed target ) Target : W Beam 345MeV/A Beam Spot radi : 1mm Water Cool radi : 13.5mm ( Disk target ) Tmp(W) =3387C Beam Spot Temp [C] 0 d/r Tmp(Be) =1278C gain x10 Ca O estimated goal point Xe Kr Ca Ne O C -Disk Beam Spot Temp [C] pua Prim.Beam [pua] Prim.Beam [pua] κ Although both target are energy loss equivalent thickness (d/r : thick / range = 0.2~0.8), [W/(m.K)] why the beam spot temperature is different? because, thickness & therm. conductivity are different 0 d/r gain x10 Ca O Xe Kr Ca Ne O C -Disk Tmp [C] Be W Primary beam Xe 86Kr 48Ca 22Ne 18O 13C energy [MeV/A] Target [mm] thickness : Ltg *) [g/cm2] Energy loss : de [kw/1pμa] *) Here, Ltg is selected as 50% of the stopping range of the primary beam. Primary beam Xe 86Kr 48Ca 22Ne 18O 13C energy [MeV/A] Target [mm] thickness : Ltg *) [g/cm2] Energy loss : de [kw/1pμa] ρ(be) = 1.8 g/cm3 ρ(w) ~ 18.5 g/cm3 Because of this, I used W target for present week beam condition. RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 22

23 roadmap Beam spot temp. [C] Target : Be 345MeV/A Ca O Ca_Exp 10mm O_Exp 40mm _Disk(ANSYS) ( Fixed target ) estimated goal point Beam spot temp. [C] Target : Be ( Disk target ) Ca O Beam spot temp. [C]. Target : Be 00 0 Fixed target on a same line Fixed & Disk target nearly on a same line (note) κ(be) 218 ~ κ(w) 177 W/(m.K) Target : Be, W 00 ( Fixed target ) ( Disk target ) Beam spot temp. [C] Beam intensity [pua] Heat Load [kw] Heat Density [kw/mm] Be 0.1 targ Target : W 345MeV/A Fix target data ( Fixed ) Rot.Disk data ( Disk ) Ca O Beam spot temp. [C]. Ca 00 O 0 Ca_Exp rpm Ca_Exp 300rpm _Ansys 500rpm Target : W 00 0 Target : W Beam intensity [pua] Heat Load [kw] Heat Density [kw/mm] Change X: Heat Load up to 1kW Beam spot temp. [C]. Beam spot temp. [C]. 10 Change X: Heat Density W targ. estimated goal point Heat Density [kw/mm] Exp. used different target (Be,W), but we can compare them in the unit of Heat Density. Although present heat density is 1/10 of the goal point, Both target material data look like following estimation curves. RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 23

24 Summary Beam spot temperature monitoring under high radiation environment is ready Fiber scope : for long time monitoring during an experiment Thermo viewer : to check & compare temperature distribution with simulations. Although present beam power is less than 1/20 of goal value, beam spot temperature on Be, W target were measured. Both data of fixed target and disk target look like following the estimated temperature curve scalded in the unit of energy loss density. ( Issues ) Discrepancy between ANSYS simulation and experimental data still remains. Beam spot temperature of rotating disk target shows vibration. Precise analysis should be necessary, in order to estimate thermal conductivity of water way and thermal contact. RIKEN Ayoshida : Beam spot temperature monitoring on production target of BigRIPS separator 24