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Update of US Gd-LS. Minfang Yeh and Richard L. Hahn BNL, Chemistry Department, Upton NY. 430 nm. Optical of ~1% Gd in LAB and in PC. Few percents of Gd can be loaded into pure LAB or pure PC, respectively, using BNL carboxylate recipe. Both LS needs additional organic solvent: - PowerPoint PPT Presentation
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Update of US Gd-LS
Minfang Yeh and Richard L. HahnBNL, Chemistry Department,
Upton NY
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430 nm
Optical of ~1% Gd in LAB and in PC
Few percents of Gd can be loaded into pure LAB or pure PC, respectively, using BNL carboxylate recipe.
Both LS needs additional organic solvent: Gd-LAB needs diluent (PC) to dissolve certain
shifters. Gd-PC needs inert diluent (MO or dodecane) to
improve compatibility.
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0.000
0.001
0.002
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0.013
10/15/04 12/14/04 02/12/05 04/13/05 06/12/05 08/11/05 10/10/05 12/09/05 02/07/06 04/08/06 06/07/06
Calendar Date
abs l
at 43
0 nm
1.2% Gd in PC 0.2% Gd in PC0.2% Gd in 20%PC 80% Dodecane0.2% Gd in LAB0.2% Gd in 20%PC 80%LAB
566 days
514 days
426 days
189 days
May 08, 2006
189 days
Stability of Gd-LS in PC (10 cm cells)
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BNL Proposed Gd-LS (1) Gd in LS Gd-Carboxylate
Liquid Scintillator
PC + dodecane
Loading Methods
Solvent-solvent Extraction
[Gd] 1 g/L
Density ~0.79 g/mL
> 15m
Stability > 1.5 years
Future Study
Mature and ready for
prototype study; Compatibility
Test
0.2%Gd in 20%PC 80% dodecane
0
0.005
0.01
0.015
0.02
350 400 450 500 550 600 650 700l(nm)
Abs
AttLl
12 L of 0.2%Gd in 20%PC + 80%dodecane situated at the University of Chicago for prototype
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Light Yield as a Function of PC% in dodecane
0.00
0.20
0.40
0.60
0.80
1.00
0 10 20 30 40 50 60 70 80 90 100
PC %
S%
No
rma
lize
d
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BNL Proposed Gd-LS (2)Gd in LS Gd-Carboxylate
Liquid Scintillator
PC + LAB
Loading Methods
Solvent-Solvent Extraction
[Gd] 1 g/L
Density ~0.87 g/mL
> 15m
Stability > 6 months
Future Study
Compatibility Test
QC monitoring
0.2% Gd in 20%PC 80%LAB
0
0.005
0.01
0.015
0.02
350 400 450 500 550 600 650 700l (nm)
Abs
AttLl
Light yield is ~100% of PC
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Buffer/Shielding
Mineral Oil(C24~C28)
LAB(C11~C13)
Water
Cost
Flash Point
215oC 130oC -
PurityNot
consistentControlled production
Easy to purify
Availability
Density 0.85 g/mL 0.86 g/mL 1 g/mL
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Buoyant Force
f
f
objectfluid
objectfluid
shieldingbufferLSunloadedLSGd or ::
http://www.ac.wwu.edu/~vawter/PhysicsNet/QTMovies/PressureFluids/
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Selection of Fluors
Wavelength Shifter (shift the UV light to the visible region)
Primary Secondary
Concentration (1.5 ~ 6 g/L)
td (ns)Concentration
(15 ~300 mg/L)
td (ns)
butyl-PBD 1.1bis-MSB 1.6
PPO 1.5
p-TP 0.95POPOP 1.5
PBD 1.1
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1
10
100
1000
500 700 900 1100 1300 1500 1700
Channel
Coun
ts
PBD 3g/L
PBD 3g/L MSB 15mg/L
butyl-PBD 3g/L
butyl-PBD 3g/L MSB 15mg/L
1
10
100
1000
500 1000 1500 2000 2500 3000
Channel
Coun
ts
butyl-PBD 3g/L
butyl-PBD 3g/L MSB 15mg/Lbutyl-PBD 30g/L
butyl-PBD 30g/L MSB150 mg/L
Q1: Adding bis-MSB in butyl-PBD doesn’t improve the light yield much; on the other hand, additional bis-MSB in PBD increases the light yield by a factor of ~2.
Q2: What are the quantities of shifters that we need?
Example of PBD vs butyl-PBD
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0.00
0.20
0.40
0.60
0.80
1.00
0 5 10 15 20 25 30 35 40
Flours (g/L)
S%
no
rma
lize
d
Light Yield as a Function of Fluors (butyl-PBD:bis-MSB=200:1)
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Blending of Conc. Gd-LS Immiscibility of solvents. Localization of Gd compound can
cause irreversible precipitation Controlled Mixing:
Fast and vigorous (not suitable for massive quantity)
Slow and gentle, i.e., Gd-PC/MO at ~3L/min (Palo Verde at 200 L per batch)
Commercially available 100-L (capable of upgrade to 300-L) Jacketed System with air or electric pump
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Port of Houston
photos adapted from NOvA
20ft by 8ft ISO tank, the shipping container conforming to the standards set by International Standards Organization, can be leased at ~few $thousands per year.
The tank shell is made of stainless steel and holds 6,341 gallons of liquid.
Transportation and Storage of LS
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Gd/H and C/H Ratios
Cold/Thermal Neutron AnalysisInstitute of Isotopes, Dept. of Nuclear ResearchHungary Academy of Science, Budapest, Hungary
Samples sent out on May 20, 20061. 0.1% Gd in 90% LAB and 10% PC2. 0.1% Gd in 80% dodecane and 20% PC3. 80% dodecane and 20% PC4. 100% LAB
Samples received on June 04, 2006; will be analyzed next week.
Nuclear Magnetic Resonance
Brookhaven National Laboratory, Chemistry Dept.A FaST team (Dr. S. Seleem and her students) will work with us at BNL beginning on June 26.
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Summary and Future Work Samples of 0.1~0.2% of Gd in a variety of liquid scintillators
and their mixtures are continuously monitoring : 546 days for 0.2%Gd in 100%PC 416 days for 0.2%Gd in 20%PC-80%dodecane 456 days for 0.2%Gd in 40%PC-60%dodecane 189 days for 0.2% Gd in 100%LAB 189 days for 0.2% Gd in 20%PC - 80%LAB
The productivity of Gd-LS at 1-L of 1%Gd-LS (~ 10L of 0.1%Gd-LS) per preparation is consistent; exploring the techniques and equipments for even larger quantity (10L of 1% Gd-LS) production.
Fluorescence for fluors in different combinations of liquid scintillators need to be studied further.
People Compatibility test of acrylic vs. organic solvent. Chemical assays to remove and to measure U/Th. Prototype in Aberdeen Tunnel HK