Study of scintillation stability in KBr, YAG:Ce, CaF2:Eu and CsI:Tl irradiated by various-energy protons Ling-Ying Lin National Superconducting Cyclotron Laboratory, U.S.A. Ling-Ying Lin, 9/17/2014, Slide 1
Motivation Camera CsI:Tl Ion beam Scintillator screen CaF2:Eu YAG:Ce Under HH 22 + irradiation: 1500 kev, 125 pa Ling-Ying Lin, 9/17/2014, Slide 2
Motivation YAG:Ce under HHHH + irradiation: 58 kev, 394 pa 1 Scintillation degradation Normalized scintillation intensity 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 100 200 300 400 500 600 700 800 Irradiation time (s) ReF: L. Y. Lin et al., Scintillation degradation of YAG: Ce under low-energy ion bombardment, JINST 6 P07010 (2013). The irradiation experiments in the rare isotope ReAccelerator (ReA) facility of NSCL : A variety of materials: CsI:Tl CaF2:Eu YAG:Ce (Y 3 Al 5 O 12 : Ce) KBr A wide range of irradiation energies: 600 kev/u 1010 kev/u 1500 kev/u 2150 kev/u Low irradiation intensity: < 400 pa Ling-Ying Lin, 9/17/2014, Slide 3
Experimental Setup stable source H2+ Low Energy Beam Transport RFQ SRF linac Scintillator Target Chamber ReA experimental area Ling-Ying Lin, 9/17/2014, Slide 4
CsI:Tl Scintillation Response Light Yield VS. Irradiation Time Beam current Light output per pa per sec 9 x 106 8 7 6 5 4 3 2 1 2150 kev/u 1500 kev/u 1010 kev/u 600 kev/u 0 0 500 1000 1500 2000 2500 3000 3500 4000 Irradiation time (sec) 90 pa 125 pa 150 pa 175 pa Ling-Ying Lin, 9/17/2014, Slide 5
YAG:Ce Scintillation Response 7 x 105 Light Yield VS. Irradiation Time Beam current Light output per pa per sec 6 5 4 3 2 2150 kev/u 1500 kev/u 1010 kev/u 600 kev/u 90 pa 125 pa 240 pa 1 0 500 1000 1500 2000 2500 3000 3500 4000 4500 Irradiation time (sec) 380 pa Ling-Ying Lin, 9/17/2014, Slide 6
CaF2:Eu Scintillation Response Light Yield VS. Irradiation Time Beam current Light output per pa per sec 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 2 x 106 0 0 500 1000 1500 2000 2500 3000 3500 4000 Irradiation time (sec) 2150 kev/u 2150 kev/u After break 1500 kev/u 1010 kev/u 600 kev/u 20 pa 125 pa 240 pa 295 pa Ling-Ying Lin, 9/17/2014, Slide 7
CaF2:Eu Scintillation Response Light Yield VS. Particle dose ( iiiiiiii mmmm 22 ) Normalized light output per pa per sec 1 0.95 0.9 0.85 0.8 0.75 0.7 0.65 0.6 2150 kev/u 1500 kev/u 1010 kev/u 600 kev/u 0.55 0 2 4 6 8 10 Particle dose (mm - 2) x 10 10 Ling-Ying Lin, 9/17/2014, Slide 8
CaF2:Eu Scintillation Response Possible radiation damges of CaF2: Eu at room temperature Interstitial F Eu 2+ Eu 3+ Beam irradiation F Ca 2+ Eu 2+ Interstitial F Eu 3+ Eu 2+ Eu 3+ Broad emission at ~425 nm Sharp emission lines at 574, 612, 626 nm, Ling-Ying Lin, 9/17/2014, Slide 9
KBr Scintillation Response Light Yield VS. Irradiation Time Beam current Light output per pa per sec 16000 14000 12000 10000 8000 6000 4000 2000 0 0 500 1000 1500 2000 2500 3000 3500 4000 Irradiation time (sec) 2150 kev/u 1010 kev/u 600 kev/u 221 pa 254 pa 370 pa Ling-Ying Lin, 9/17/2014, Slide 10
KBr Scintillation Response Light Yield VS. Particle dose ( iiiiiiii mmmm 22 ) Normalized light output per pa per sec 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0 2 4 6 8 10 12 14 x 10 11 Particle dose (mm - 2) 2150 kev/u 1010 kev/u 600 kev/u The KBr sample after ion irradiation. Ling-Ying Lin, 9/17/2014, Slide 11
KBr Scintillation Response Possible luminescence mechanism of KBr at room temperature Ling-Ying Lin, 9/17/2014, Slide 12
Scintillation Yield comparison 10 8 light output per pa per sec 10 6 10 4 10 2 CsI:Tl CaF2:Eu YAG:Ce KBr YAG:Ce CsI:Tl CaF2:Eu KBr 500 1000 1500 2000 2500 beam energy (kev/u) CsI:Tl and YAG:Ce CaF2:Eu KBr Average luminescence during irradiation Average luminescence after it maintains stable scintillation Maximum luminescence Ling-Ying Lin, 9/17/2014, Slide 13
Scintillation Response at low and high beam energies YAG:Ce under HH 22 + irradiation CaF2:Eu under HH 22 + irradiation Normalized light output 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 25 kev/u 600 kev/u Normalized light output 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 25 kev/u 600 kev/u 0.2 0.2 0.1 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 x 10 12 Particle dose (mm - 2) 0.1 0 2 4 6 8 10 12 x 10 11 Particle dose (mm - 2) 25 kev/u data were measured by C. Benatti and G. Perdikakis in the low energy beam transport section of the ReA facility. Ling-Ying Lin, 9/17/2014, Slide 14
Scintillation Response at low and high beam energies SRIM simulation for YAG under proton irradiation 600 kev/u The production The production of the scintillation photons photons The production of the defects. 25 kev/u Ling-Ying Lin, 9/17/2014, Slide 15
Beam Width Comparison HH 22 + irradiation at the beam energy 2150 kev/u and current 12 pa vertical pixel vertical pixel vertical pixel 10 20 30 40 10 20 30 40 10 20 30 CsI:Tl 10 20 30 40 50 60 horizontal pixel CaF2:Eu 10 20 30 40 50 60 horizontal pixel YAG:Ce 10 20 30 40 50 60 horizontal pixel x 10 4 6 4 2 15000 10000 5000 10000 8000 6000 4000 2000 index(indensity) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 The vertical cross section profile 0-2 -1.5-1 -0.5 0 0.5 1 1.5 2 position (mm) CaF2:Eu CsI:Tl YAG:Ce Ling-Ying Lin, 9/17/2014, Slide 16
Beam Width Comparison beam width 1-sigma (mm) beam width 1-sigma (mm) 0.55 0.5 0.45 0.4 0.7 0.65 curve(1) 0.6 0.55 HH 22 +, 2150 kev/u, 12 pa 0.35 0 500 1000 1500 beam irradiation time (second) HH 22 +, 600 kev/u, 380 pa curve(3) curve(2) 0.5 0 500 1000 1500 2000 2500 3000 3500 4000 beam irradiation time (second) CaF2:Eu CsI:Tl YAG:Ce KBr YAG:Ce index(indensity) 3000 2500 2000 1500 1000 500 the vertical cross section profile on KBr 4 sec 82 sec 2527 sec curve(2) curve(1) curve(3) 0 0 10 20 30 40 50 60 70 vertical pixel (1 pixel length=0.0815mm) The beam width (1-σσ): HH 22 +, 600 kev/u, 380 pa curve(1) curve(2) curve(3) 0.616 mm 0.539 mm 0.674 mm Ling-Ying Lin, 9/17/2014, Slide 17
Conclusions Under HH 2 + irradiation at the beam energies of 600-2150 kev/u and beam current of less than 400 pa: Light Yield Light Yield VS. ion energy Scintillation stability CsI:Tl CaF2:Eu YAG:Ce KBr Stable CsI:Tl > CaF2:Eu > YAG:Ce > KBr Linear After an initical rapid decay, it becomes stable Stable Unstable Beam width Almost consistent and stable during irradiation Unstable Under low-energy ion bombardment, ion-induced defects are highly efficient to degrade transparency of scintillation photons inside an irradiated scintillator. Ling-Ying Lin, 9/17/2014, Slide 18
Thank you Ling-Ying Lin, 9/17/2014, Slide 19
(Eu2+) (Eu3+) Ling-Ying Lin, 9/17/2014, Slide 20