Performance and application of ultrafast pulse radiolysis ... · Time resolution vs. dose (1) 2~3ps...
Transcript of Performance and application of ultrafast pulse radiolysis ... · Time resolution vs. dose (1) 2~3ps...
Jul. 26th, 2004Brookhaven National Laboratory, USA
Yusa Muroya, Mingzhang Lin, Hokuto Iijima,Toru Ueda, Mitsuru Uesaka, Yosuke Katsumura
Nuclear Engineering Research LaboratoryUniversity of Tokyo, JAPAN
Performance and application ofultrafast pulse radiolysis system using
laser photocathode rf-gun combined with fs laser
PD1 PD2
FC
Shutter2(On/Off)
White light cell(D2O)
Fs laser(795nm)
Linac
Sample
BPF(400-1100nm)
Dielectric mirror795nm
Delay stage
Shutter1(On/Off)
• Optical delay system • Reference light for normalization of laser’s fluctuation• Elimination of noise by 2 shutters (beam on/off, laser on/off)
www.utnl.jp/~beamBeam-Material InteractionsMeasurement System
Laser(265nm)
www.utnl.jp/~beamBeam-Material InteractionsMeasurement System
795nm
White light cell
Beam splitter
BPFSample
PD1 PD2
www.utnl.jp/~beamBeam-Material InteractionsData Acquisition System
Shutter for pump
LabVIEW&
GPIB
PIN photodiode1
PIN photodiode2
Charge monitor
Optical delay stage
(1)linac/laser On/On Off/On On/Off Off/Off
Meas.1 Meas.2 Meas.3 Meas.4 O.D.calc.
Delay
(2)oscill.&com.(3)delay system
Pulse generator
Oscilloscope
Measurement scheme
GPIB
Shutter for probe
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0 50 100 150 200 250 300
H2O1M HClO4
Time /ps
30ps
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0 50 100 150 200 250 300Time [ps]
www.utnl.jp/~beamBeam-Material InteractionsPreliminary Pulse Radiolysis
00.040.08
0 10 20 30 40
9ps
In 1999
In 2002
00.20.40.60.8
1
0 50 100 150 200 250 300Inte
nsity
[a.u
.] Charge [a.u.]
I0
ICharge
1664Average9ps30psTime resol.
795nm (Fundamental)Wavelength
0.8-1.0nC4mm3ps
0.8-1.0nC4mm7ps
ChargeBeam sizePulse width
5 mm20 mml / mmH2OH2O&1M H+
Condition
Results- O.D. still low
www.utnl.jp/~beamBeam-Material InteractionsImprovement : dose increase & λ extend
Time resolution vs. dose(1) 2~3ps : pulse width (EB)(2) 100fs : pulse width (laser)(3) <1ps : synch.(4) 5ps /5mm : ∆t passing through H2O
→ Thinner cell & focused EB
OK
Note: O.D. = ε C l l↓ for better time resolution, but O.D.↓then, C↑ for O.D.→
H2O(5mm)EB
>40Gy/pulse13-15GyDose2ps3psPulse width
3mm4mmBeam size1.7-2.0nC0.8-1.0nCChargeCurrentPrevious
Estimation of dose by RadColor
Introduction of white light continuum- 795nm → white- Worse stability of intensity- S/N↓ then average↑
CurrentPrevious400-1100nm795nmWavelength
6416Average~0.015 OD~0.005 ODNoise
- Accumulation 2000pulses- Red region corresponds to 80-100kGy
Improvement
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0 50 100 150 200 250Time /ps
Optical path : 10 mm
5 mm
2 mm1 mm
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-10 -5 0 5 10 15 20 25 30Time /ps
12-13ps
6-7ps
4-5ps
<4ps
• Time behaviors of eaq- at 700nm
Results
Time resolution: δtotalδtotal = δdiff + (δE
2 + δL2 + δsync
2 )1/2
Dominant factor: δdiffdue to refractive index n=1.33
Radiolysis of water measured at 700nm www.utnl.jp/~beamBeam-Material Interactions
50Gy50Gy47Gy40GyDose
<4ps4-5ps6-7ps12-13psTime resol. /ps
0.043
0.085
0.1910
0.3215
O.D.S/N
12510l /mm
12.2ps 3.2ps5.2ps7.2psTime resol. /ps
Good agreement
SPR KPR Dose Scav. Sim. G(time) 1970 Tront --- Kinetics only 1973 Tront ● ● 4.0(30ps)
● ● 4.0(30ps) 1973 ANL ● ● 4.1(200ps) Sub-ns KPR 1975 Tront ● ●
● ● 4.6(dry) Dry electron 1976 ANL ● ●
(1973) 4.6(100ps)
4.1(1ns) Reconcilation
1973 1985 Hokkaido ● ● 4.8(30ps) 1985
- 1996
● ●
1996 NDRL & ANL
● ● 4.8(100ps) Reconciliation 1976
1999 ANL ● ● 4.0 (time zero)
Fs laser Reconciliation
2000 Tokyo ● ● ●
G [molecules/100eV]www.utnl.jp/~beam
Beam-Material InteractionsG-value of the solvated electron
nH2O
H2O+ + e-
H2O* → H2O+ + e-
- Initial G: 4.0~4.8- Primary G: 2.7
Reported G(eaq-)
Which G is reliable ?
epre- → eaq
-
eaq- , H3O+, H, OH, H2, H2O2
<1ps
~100ns
0
1
2
3
4
5
6
10-12 10-11 10-10 10-9 10-8 10-7 10-6
Time /s
G=4.1
G=2.7G=2.38
Monte-Carlo simulation [1]
www.utnl.jp/~beamBeam-Material InteractionsApplication of RF-Gun Pulse Radiolysis
• G(eaq-) measured at 795 & 633nm
• Ps by SPR (795nm)• Ns by KPR(He-Ne laser) (633nm)
Condition
G(20ps)=4.17±0.22
Time resolution
Note1 : O.D. already normalized by chargeNote2 : O.D. at 633nm normalized by ε
ε : 15500(633nm), 16800 (795nm)
Stroboscopic method Kinetic method
ArGas
64Average
0.8-1.0nC4mm3ps
ChargeBeam sizePulse width
18 mml / mm
H2OSample
[1] Y. Muroya, J.-P. Jay-Gerin, Y. Katsumura et al,Can. J. Chem., 80 (2002) 1367
www.utnl.jp/~beamBeam-Material InteractionsG of solvated electron in alcohols
21.514.1[1]11[7]7.8[2][1]51
14000(650nm)[7]2.01-decanol
3.18.95[1]7.36[7]10.3[2][1]451.41-octanol
3.82.56[7]17.1[2][1][2]
3039[6]
12000(635nm)[7]
1.92.3
1-butanol
6.52.04[7]18.3[2]
[1][3][2][5]
258400(575nm)
14000(?)13000(820nm)[7]
2.31.52.8,1.81.0
2-propanol
81.92[7]20.1[2]
[3][4][2][5]
24[1]34[6]
8400(575nm)12800(700nm)
13000(?)11000(640nm)[7]
1.82.02.9,2.31.0
1-propanol
10.21.07[7]24.3[2]
[1][3][4][2][5]
1823[6]12000(575nm)
9300(700nm)
15000(?)9900(690nm)[7]
2.71.63.42.81.0
Ethanol
14.80.55[7]32.6[2]
[1][3][4][2][5]
1110.7[6]15500(575nm)
10200(630nm)
17000(?)10400(630nm)[7]
2.51.63.43.1,3.01.1
Methanolρ/1021cm-3[1]η/cPDRef.τsε /M-1cm-1G
7500(570nm)[7]Propylene Glycol(1.04)(1,2-PrD)
6000(575nm)[7]1,3-Propanediol(1.05)
9700(530nm)[7]Glycerol(1.26)(1,2,3-PrTri)
19.9[1]37.7[4][5]
<5[1]26
14000(580nm)14000(?)
2.31.2
Ethylene Glycol
ρ/1021cm-3[1]η/cPDRef.τsε /M-1cm-1G
www.utnl.jp/~beamBeam-Material InteractionsG of solvated electron in alcohols
[1]G.A.Kenny-Wallace, C.D.Jonah, J.Phys.Chem., 86 (1982) 2572[2]R.R.Hentz, G.A.Kenny-Wallace, J.Phys.Chem., 78 (1974) 514[3]W.K.Wolff, J.W.Hunt, J.Phys.Chem., 77 (1973) 1350[4]T.Sumiyoshi, M.Katayama, Bull.Chem.Soc.Jpn., 58 (1985) 3073
[5]M.J.Bronskill, J.W.Hunt, J.Chem.Phys., 53 (1970) 4201[6]W.J.Chase, J.W.Hunt, J.Phys.Chem., 79 (1975) 2835[7]C.Ferrandini, J.-P.Jay-Gerin, CRC press, (1991) 259
www.utnl.jp/~beamBeam-Material InteractionsG of solvated electron in alcohols
G(MeOH) = 4.1 @50psG(EtOH) = 3.6 @50ps
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Methanol
Ethanol
600nm
1100nm
700nm
1100nm
Ethanol700nm1100nm
600nm1100nm
Wavelength
64Average10 mml / mm
MethanolSample
Dose : 37Gy
• Initial G(esol-) measured at VIS&IR
Condition
Procedure of G-value determination(1) H2O measurement at 700nm(2) Dose calculation(3) Alcohols measurement at λmax
www.utnl.jp/~beamBeam-Material InteractionsResults and discussion
ε is correct?
Shorter τLarger dielectric constant→ large G
fs laser reported-esol
- doesn’t recover ~10%
esol-(MeOH) > esol
-(EtOH) ~ eaq-
Necessity to measure whole time region from ps to µs
366006.16000(600nm)
1,3-Propanediol(1.05)
330004.08250
(600nm)Glycerol(1.26)(1,2,3-PrTri)
330004.47500(570nm)
Propylene Glycol(1.04)(1,2-PrD)
768004.218300(700nm)
H2O(1.00)
392002.814000(600nm)
EG(1.1)
337502.513500(600nm)
1-decanol(0.84)
290002.511500(700nm)
1-butanol(0.81)
276002.312000(700nm)
2-propanol(0.79)
343002.712700(700nm)
1-propanol(0.80)
356403.69900
(700nm)Ethanol(0.79)
410004.110000(600nm)
Methanol(0.79)
Initial GεInitial Gε /M-1cm-1Solvent (ρ /cm3)
??
0.000
0.050
0.100
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0 50 100 150 200 250
700nm1100nm
Time /ps
1-PrOH
www.utnl.jp/~beamBeam-Material InteractionsResults and discussion
Report
This work18077502813τ (ps)@1100nm5130241810τs (ps)
32
9PrOH
10BuOH
15119τ (ps)@700nm or 600nm
2210τ (ps)@1300nm
DeOHEtOHMeOH
• Formation time is faster than previous reports• Decay appreciates with previous reports
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Methanol
Ethanol
600nm
1100nm
700nm
1100nm
www.utnl.jp/~beamBeam-Material InteractionsRadiolysis of water : spectrum
0.000.050.100.150.200.250.300.35
400 500 600 700 800 900 1000 1100
ReportedH2O5M NaOH
Wavelength /nm
64Average400 – 1100 nmWavelength
10 mml / mmH2O & 5M NaOH
• G(eaq-) measured from VIS to IR
Condition
<700nm : O.D.(alkali) > O.D.(neat)>700nm : O.D.(alkali) < O.D.(neat)
20% absorption increase7% density increase Increase of G
www.utnl.jp/~beamBeam-Material InteractionsSummary
• Development of new pulse radiolysis system combined withlaser photocathode rf-gun and fs white light continuumhas been almost completed.
• <4ps time resolution was achieved.
• It has been started application of the system to clarifyradiation-induced fast processes, i.e., G-value of eaq
- ,esol
- from several kinds of alcohol.