Application of quartz glass, polyimide optical fiber sensors and crystal detectors to measurement of charged- particles, gamma and neutron dose in tokamak

Application of quartz glass, Application of quartz glass, polyimide optical fiber sensors polyimide optical fiber sensors and crystal detectors to and crystal detectors to measurement of charged-measurement of charged-particles, gamma and neutron particles, gamma and neutron dose in tokamakdose in tokamak

Group content:

Prof. P.S. dr hab. Inż. S.M. KaczmarekProf. dr hab. Ewa Weinert-RączkaProf. Dr Arlen Valozhyn (polyimides)Dr Hubert FuksDr Danuta PiwowarskaDr Jerzy GajdaMgr Adam WorsztynowiczMgr Grzegorz Leniec

Partners:MOL groupEspany group

Main goalsMain goalsProcessing and investigation of nonlinear opticalProcessing and investigation of nonlinear opticalmaterials:materials:- LiLi22BB44OO77 as SHG, 4HG, 5HG as SHG, 4HG, 5HG- SrSrxxBaBa1-x1-xNbNb22OO6 6 - pyroelectric- pyroelectric- High glass transition temperature polyimidesHigh glass transition temperature polyimides

2. Neutron SS scintillators based on Li2. Neutron SS scintillators based on Li22BB44OO77

3. Fiber optical neutron and gamma sensors3. Fiber optical neutron and gamma sensors

Abstract. New optical fibre sensors of ionizing radiation are proposed build of quartz glass and polyimides with higher glass temperature limit and the testing of the materials under high flux irradiation with 14 MeV neutrons. Also classical sensors (strain, temperature) build of quartz glass we are going to test for their radiation hardness. Moreover, some kinds of other crystal detectors of the temperature, charge particles, gammas and neutrons will be produced, investigated and tested (e.g. Li2B4O7, SrxBa1-xNb2O6)

Optoelektronika i fizyka materiałowaOptoelektronika i fizyka materiałowa 22

Neutrons are always detected through nuclear reactions that create charged particles. Slow- and fast- neutron detectors contain conversion materials that react to incident neutrons by generating charged particles. The materials used for this purpose (a fill gas, coating, foil, etc.) are stable isotopes having a high efficiency of conversion for the given type of radiation. The produced charges are detected by transduction elements having structures similar to those used for , -, or -radiation. The representative conversion materials for slow-neutron detection are isotopes 6Li and 10B, and, for fast- neutron detection, 3H and 6LiF.

Slow- and fast-neutron detectors. SN and FN = slow-and fast-neutron radiation, 1 = conversion material, 2 = transduction element for -,

or -radiation, 3 = case.

Sensing/Interaction Mechanisms: Fundamental mechanisms and interactions that allow detection and measurement of nuclear/ionizing radiation (e.g., free carrier generation in materials, optical scintillation, optically active defect creation in detectors, etc.).


Neutron DetectorsNeutron Detectors What does it mean to “detect” a neutron? What does it mean to “detect” a neutron?

– Need to produce some sort of measurable quantitative (countable) Need to produce some sort of measurable quantitative (countable) electrical signalelectrical signal

– Can’t directly “detect” slow neutronsCan’t directly “detect” slow neutrons Need to use nuclear reactions to “convert” neutrons into charged Need to use nuclear reactions to “convert” neutrons into charged

particlesparticles Then we can use one of the many types of charged particle detectorsThen we can use one of the many types of charged particle detectors

– Gas Gas filled filled proportional countersproportional counters, , 33He, BFHe, BF33, H, H33BOBO33 and ionization and ionization

chamberschambers – efficient for thermal neutrons (0.025eV) – efficient for thermal neutrons (0.025eV)– Scintillation detectorsScintillation detectors, , Li glass (Ce)Li glass (Ce), , LiLiFF (Eu) (Eu), , ZnS (Ag) – LiFZnS (Ag) – LiF, ,

YAP:CeYAP:Ce– Semiconductor detectorsSemiconductor detectors

barns8.1

5333 n + n + 33He He 33H + H + 11H + 0.764 MeVH + 0.764 MeV

n + n + 66Li Li 44He + He + 33H + 4.79 MeVH + 4.79 MeV

n + n + 1010B B 77Li* + Li* + 44HeHe77Li + Li + 44He + 0.48 MeV He + 0.48 MeV +2.3 MeV +2.3 MeV (93%)(93%)

77Li + Li + 44He +2.8 MeVHe +2.8 MeV ( 7%)( 7%) - - 1010B(n,B(n,))77LiLi n + n + 155155Gd Gd Gd* Gd* -ray spectrum -ray spectrum conversion electron spectrum conversion electron spectrum n + n + 157157Gd Gd Gd* Gd* -ray spectrum -ray spectrum conversion electron spectrum conversion electron spectrum n + n + 235235U U fission fragments + ~160 MeV fission fragments + ~160 MeV n + n + 239239Pu Pu fission fragments + ~160 MeV fission fragments + ~160 MeV Detection efficiencyDetection efficiency

barns8.1

940

tN


Scintillation fiber detector develped by the Los Alamos National Laboratory

http://wsx.lanl.gov/scifi.htm


More recently, neutron detectors based on 6LiF converters (LiF, Li2O, Li6Gd(BO3)3 ) and silicon semiconductor diodes have been tested. The principle of this kind of neutron detection is completely different from the method used with scintillation detectors:Thermal or sub-thermal neutrons are absorbed in a thin 6LiF converter. The reaction products reach the semiconductor and generate electron hole pairs. On average half of the kinetic energy of the reaction product 3H is deposited in the depletion region of the silicon diode since the converter has a thickness of 16µm and the range of the 3H particle is 32µm. Under construction are such one- and two-dimensional detectors for slow neutrons for evaluating detector properties. With this detector type a high spatial resolution of e.g. 100µm is achievable. The detector is insensitive to varying magnetic fields, in contrast to a detector based on photomultipliers. For two dimensional detectors each x and y strip on the diode needs its own amplifier chain in order to determine the position of incidence.


Nuclear Track Detectors were mounted with the boron converter on their surface as one compres-sed unit to assess accumulated low doses of thermal neutrons around neutron source storage area. The converter is a lithium tetraborate (Li2B4O7) layer for thermal neutron detection via 10B(n,alpha)7Li and 6Li(n,alpha)3H nuclear reactions. The study indicates that the area passive neutron dosimeter was able to detect accumulated doses as low as 40 nSv x h(-1), which could not be detected with the available active neutron dosimeters.

LiLi22BB44OO77

neutronneutronscintillatorscintillator

Kaczmarek


Optoelectronic Head IF SUT Optoelectronic Head IF SUT dr hab. inż. Prof. PS - Sławomir M. Kaczmarekdr hab. inż. Prof. PS - Sławomir M. Kaczmarek

Scintillator materials made up in SUT: BGO – master Scintillator materials made up in SUT: BGO – master scintillator material.scintillator material.SUTSUT K05002 pixel K05002 pixel (2*2*10 mm) (2*2*10 mm)::

horizontallyhorizontally LY LYhorhor = 828 phe/MeV = 828 phe/MeV

verticallyvertically LY LYverver = 404 phe/MeV = 404 phe/MeV

resolutionresolution R R00 = 8.59 % = 8.59 %

Light yieldLight yield LY LY00 = 1084 phe/MeV = 1084 phe/MeV

Absorption coefficientAbsorption coefficient = 1.16 cm = 1.16 cm-1-1

PML BGO Photonic MaterialsPML BGO Photonic Materials N13363-8 pixelN13363-8 pixel (2*2*10 mm) (2*2*10 mm)::

horizontallyhorizontally LY LYhorhor = 847 phe/MeV = 847 phe/MeV

verticallyvertically LY LYverver = 471 phe/MeV = 471 phe/MeV

Light yieldLight yield LY LY00 = 1057 phe/MeV !!! = 1057 phe/MeV !!! (bra(bravvo o SUTSUT!!!)!!!)

Absorption coefficientAbsorption coefficient = 0.90 cm = 0.90 cm-1-1 (tym oni g (tym oni góórujrująą))

dr Winicjusz Drozdowski, Zakład Optoelektroniki, Uniwersytet im. M. dr Winicjusz Drozdowski, Zakład Optoelektroniki, Uniwersytet im. M. Kopernika, ToruńKopernika, Toruń

BGOBGO

1. Scintillators1. Scintillators

MetodaMetodaCzochralskiegoCzochralskiego



SHG of Nd:YVO laserSHG of Nd:YVO laser4 4 (1.06 (1.06 m)m)

with efficiency >30% : 3*3*18 mm made upwith efficiency >30% : 3*3*18 mm made up

from nonlinear from nonlinear LiLi22BB44OO77

Nonlinear single crystal Nonlinear single crystal SrSrxxBaBa1-x1-xNbNb22OO66: Cr: Cr – fotorefractive material, relaksor: – fotorefractive material, relaksor:

Holographic imaging, piezotechnic, nonlinear optics (mixing of wavelengths)Holographic imaging, piezotechnic, nonlinear optics (mixing of wavelengths)

Langesites: Langesites: LGT, LGT:Yb, Ho, LGT:CoLGT, LGT:Yb, Ho, LGT:Co

Lithium tetraborate: Lithium tetraborate: LBO, LBO:Co, LBO:MnLBO, LBO:Co, LBO:Mn

2. Nonlinear single crystals2. Nonlinear single crystals

1. D. Piwowarska, S.M. Kaczmarek, W. Drozdowski, M. Berkowski, A. Worsztynowicz, "Growth andoptical properties of Li2B4O7 single crystals pure and doped with Yb, Co, Eu and Mn ions for nonlinear applications", Acta Phys. Pol. A, 107 (2005) 507-516 2. R. Wyrobek, „Przetwornik na wyższe harmoniczne lasera Nd:YAG na bazie Li2. R. Wyrobek, „Przetwornik na wyższe harmoniczne lasera Nd:YAG na bazie Li 22BB44OO77”, praca ”, praca

magisterska, promotor S.M.Kaczmarekmagisterska, promotor S.M.Kaczmarek3. B. Felusiak, „Liniowe i nieliniowe właściwości dielektryczne monokryształów Li3. B. Felusiak, „Liniowe i nieliniowe właściwości dielektryczne monokryształów Li22BB44OO77”, praca ”, praca

magisterska, promotor S.M. Kaczmarekmagisterska, promotor S.M. Kaczmarek4. D. Piwowarska, Dissertation, Szczecin 2005, promotor S.M. Kaczmarek4. D. Piwowarska, Dissertation, Szczecin 2005, promotor S.M. Kaczmarek5. D. Piwowarska, S.M. Kaczmarek, M. Berkowski, I. Stefaniuk, „5. D. Piwowarska, S.M. Kaczmarek, M. Berkowski, I. Stefaniuk, „Growth and EPR and optical Growth and EPR and optical properties of Liproperties of Li22BB44OO77 single crystals doped with Co single crystals doped with Co2+2+ ions ions”, ”, J. Cryst. GrowthJ. Cryst. Growth, in the print, in the print


3. Second order non-linear optical polymers, polyimides3. Second order non-linear optical polymers, polyimidesProf. VolozhynProf. Volozhyn

Advantage over LiNbOAdvantage over LiNbO33::

- large second-order NLO properties: d- large second-order NLO properties: d3333=30 pm/V for 1320 nm=30 pm/V for 1320 nm

- high laser damage threshold- high laser damage threshold- ease of processing and modification- ease of processing and modification- have good film-forming properties for making waveguide structures- have good film-forming properties for making waveguide structures- are compatible with existing semiconductor technologies- are compatible with existing semiconductor technologies

- increasing the T- increasing the Tgg (200-275 (200-275ooC) results in an improved poled-order stability (stability SHG) 168C) results in an improved poled-order stability (stability SHG) 168oCoC for for >1000h>1000h

ApplicationsApplications- high-speed light modulators and switcheshigh-speed light modulators and switches


First goal of our project:First goal of our project:

Producing of nonlinear optical materials for 2HG, 4HG and 5HG – Producing of nonlinear optical materials for 2HG, 4HG and 5HG – LiLi22BB44OO77 and Sr and SrxxBaBa1-x1-xNbNb22OO66. Investigation of nonlinear and linear . Investigation of nonlinear and linear optical properties of the crystals and the influence of neutron and optical properties of the crystals and the influence of neutron and gamma radiation on the propertiesgamma radiation on the properties

Producing of nonlinear polyimides for 2HG, modulators, switches. Producing of nonlinear polyimides for 2HG, modulators, switches. Investigation of nonlinear and linear optical properties of the Investigation of nonlinear and linear optical properties of the polymer and the influence of neutron and gammas on the propertiespolymer and the influence of neutron and gammas on the properties

Second goal of our projectSecond goal of our project

Producing of LiProducing of Li22BB44OO77 neutron scintillators: checking of the influence of neutron scintillators: checking of the influence of different kind of doping on the scintillation properties,different kind of doping on the scintillation properties,

Investigation of the influence of neutrons and gammas on the properties Investigation of the influence of neutrons and gammas on the properties of the crystalsof the crystals


Lithium Doped Glass Lithium Doped Glass Fiber ScintillatorsFiber Scintillators

Vehicle or helicopter mounted Vehicle or helicopter mounted arrays of gamma ray and/or neutron arrays of gamma ray and/or neutron detectorsdetectors

– Usually contain large NaI(Tl) Usually contain large NaI(Tl) scintillator crystals and large scintillator crystals and large 33He or BFHe or BF33 neutron neutron

proportional countersproportional counters

– May be combined with GPS May be combined with GPS and mapping softwareand mapping software

Fiber Optic Neutron Detectors Fiber Optic Neutron Detectors

The optical diagnostic system of future fusion The optical diagnostic system of future fusion reactors must operate in high temperature and a reactors must operate in high temperature and a severe radiation environment.severe radiation environment.The use of optical fibers is expected to significantly The use of optical fibers is expected to significantly simplify the design of such a system.simplify the design of such a system.


Crossed-Fiber Crossed-Fiber Position-Sensitive Scintillation DetectorPosition-Sensitive Scintillation Detector.. All fibers installed and All fibers installed and

connected to multi-anode photomultiplier mountconnected to multi-anode photomultiplier mount

Size: 25-cm x 25-cmSize: 25-cm x 25-cm Thickness: 2-mmThickness: 2-mm Number of fibers: 48 for each axisNumber of fibers: 48 for each axis Multi-anode photomultiplier tube: Phillips XP1704Multi-anode photomultiplier tube: Phillips XP1704 Coincidence tube: Hamamastu 1924Coincidence tube: Hamamastu 1924 Resolution: < 5-mmResolution: < 5-mm Shaping time: 300 nsecShaping time: 300 nsec Count rate capability: ~ 1 MHzCount rate capability: ~ 1 MHz Time-of-Flight Resolution: 1 msecTime-of-Flight Resolution: 1 msec

The scintillator screen for this 2-D detector consists of a mixture of 6LiF and silver-activated ZnS powder in an epoxy binder. Neutrons incident on the screen react with the 6Li to produce a triton and an alpha particle. Collisions with these charged particles cause the ZnS(Ag) to scintillate at a wavelength of approximately 450 nm. The 450 nm photons are absorbed in the wavelength-shifting fibers where they converted to 520 nm photons emitted in modes that propagate out the ends of the fibers. The optimum mass ratio of 6LiF:ZnS(Ag) was determined to be 1:3. The screen is made by mixing the powders with uncured epoxy and pouring the mix into a mold. The powder then settles to the bottom of the mold before the binder cures. After curing the clear epoxy above the settled powder mix is removed by machining. A mixture containing 40 mg/cm2 of 6LiF and 120 mg/cm2 of ZnS(Ag) is used in this screen design. This mixture has a measured neutron conversion efficiency of over 90%.


Fiber-optic Strain and Temperature Sensors based on extrinsic Fabry-Perot interferometerThe interfering reflections are created outside the fiber instead of internally – and refractory ceramic construction. Sensors are needed that can operate at temperatures >1000 oC for the control and monitoring of high temperature systems such as nuclear reactors.Advantages: immunity to electromagnetic interference, extremely long lead lengths, a high level of multiplexing, and extremely low mass. The transducing mechanism used is a distance measurement technique based on the formation of a Fabry-Perot cavity between the polished end face of an optical fiber and a reflective surface. Light is emitted from a broadband source, transmitted through a coupler, and passed through the fiber at the sensor, where a portion of the light is reflected off the fiber end face – reference reflection (R1). The remaining light propagates through the transducer and is reflected back into the fiber – sensing reflection. These two light waves interfere constructively or destructively. The resulting interference pattern is interpreted in term of absolute gap between the two reflectors. The physical quantity measured is the optical path length between R1 and R2.


1 - Recoil protons – polymer1 - Recoil protons – polymer2 – diffusion of hydrogen2 – diffusion of hydrogen3 – compaction effect3 – compaction effect

Fiber optic neutron sensorsFiber optic neutron sensors



When pure quartz glasses are irradiated with e.g. -radiation, absorption bands with maxima at 4.8, 2 eV and 1.75 eV are formed. The absorption bands are caused by centers formed by nonbridging oxygen Si-O-. Irradiation of some glasses and crystals with neutrons reveals the presence of very similar bands (UV+VIS). There is known a proposition of use a differential circuit for the sensor build of quartz glass for -irradiation detection. Laser radiation with 215 nm (absorption maximum of the material) is introduced into the optical fiber, after which the fiber is separated into two fibers of identical length, fabricated from a single material. One of the fibers is placed in the medium where the irradiation dose needs to be measured, and the second remains under normal conditions. Photodiodes that record the intensity of the transmitted radiation are placed at the output of both fibers. The radiation intensity in a fiber acted on by irradiation (gamma) will be smaller because of induced absorption (proportional to radiation dose). The intensity in the fiber that remains under normal conditions is taken as the reference level. It is proposed that the returning of irradiated fiber to initial state will be possible due to cladding made from a metal network (electric current), that will heat the fiber above 200 oC.

Fiber optic gamma sensorFiber optic gamma sensor


1. S.M. Kaczmarek, A. Bensalah, G. Boulon, "-ray induced color centers in pure and Yb doped LiYF4 and LiLuF4 single crystals”, Optical Materials, 28/1-2 (2006) 123-128 (1.339)2. S.M. Kaczmarek, T. Tsuboi, M. Ito, G. Boulon, G. Leniec, "Optical study of Yb3+/Yb2+ conversion in CaF2 crystals", Journal of Physics: Condensed Matter, 17 (2005) 3771-3786 (2.049) 3. G. Leniec, 3. G. Leniec, S.M. Kaczmarek, G. Boulon, "EPR and optical properties of CaFS.M. Kaczmarek, G. Boulon, "EPR and optical properties of CaF22:Yb single crystals", :Yb single crystals", Proc. SPIEProc. SPIE,,

vol. 5958 (2005), pp. 531-540 vol. 5958 (2005), pp. 531-540

3. Analyzis of color centers in fluorides: 3. Analyzis of color centers in fluorides:

CaFCaF22, LiLuF, LiLuF44, LiYF, LiYF44, BaY, BaY22FF88, KY3F, KY3F10 10 doped with Ybdoped with Yb3+3+

200 300 400 500 600 700 800 900 1000 1100

0

2

4

6

200 300 400 500 600 700 800 900 1000 1100

0

2

4

6

x53

2

1

GF

D

C

B

A

CaF2:Yb at 290K

1: as-grown, Yb3+ 5at%

2: as-grown, Yb3+ 0.5at%

3: H2-annealed, Yb3+ 5at%

4: K

wavelength (nm)

abso

rptio

n co

effic

ient

(cm

-1)

4 K

[1/

cm]

Wavelength [nm]

200 250 300 350 400 4500

4

8

12

16

20

24

28

32

36

F

D

C

B

A3

2

1

K, K

[1

/cm

]

Wavelength [nm]

CaF2:Yb 5at.%

1 - K

2 - K 104 Gy

3 - K 105 Gy


200 300 400 500 600 700 800 900 1000 1100-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

YAG:Nd 1%

Oxygen atmosphere1-102 Gy, 2-103 Gy, 3-104 Gy4-105 Gy, 5-106 Gy, 6-107 Gy

7-1400oC 3h air

7

654 32

1

K [1

/cm

]

Wavelength [nm]

102 103 104 105 106 107

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

K

[1/c

m]

Gamma dose [Gy]

1

4

3

2

1

255 nm 385 nm 300 nm 650 nm

Influence of the annealing and Influence of the annealing and -irradiation on the absorption of YAG:Nd 1% crystal-irradiation on the absorption of YAG:Nd 1% crystal

WTW WAT

ICHTJ


100 200 300 400 500 600 700 800 900 1000 1100 1200-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Nd:YAG (1at.%) 20 MeV

5

4

32

1

87

6

5

43

1 - 5*1012 protons/cm2, 2 - 3,5*1013 protons/cm2

3 - 1,35*1014 protons/cm2, 4 - 1,135*1015 protons/cm2

5 - 5*1016 el./cm2, 1 MeV, 6 - 1,1135*1016 protons/cm2

7 - 1673 K 3h air

21K

[1/

cm]

Wavelength [nm]

1E13 1E14 1E15 1E16-2

-1

0

1

2

4

3

2

1

1 - 258 nm2 - 273 nm3 - 352 nm4 - 586 nm

K [1

/cm

]

Protons fluency [nm]

Influence of the annealing and irradiation with protons of 20 MeV energy (cyclotron)Influence of the annealing and irradiation with protons of 20 MeV energy (cyclotron)and electrons (acceler.) of 1 MeV energy on the absorption of YAG:Nd 1% crystaland electrons (acceler.) of 1 MeV energy on the absorption of YAG:Nd 1% crystal

IPJ Świerk


Third goal of our project:Third goal of our project:

Producing of the fiber optic neutron and gamma sensors based Producing of the fiber optic neutron and gamma sensors based on quartz glass and polyimides. Investigation of the influence of on quartz glass and polyimides. Investigation of the influence of gamma and neutron doses on the properties of the sensorsgamma and neutron doses on the properties of the sensors


NEW KNOWLEDGE EXPECTED FROM THE PROJECT- more detailed data on charged particle, gamma and neutron emission, - extended knowledge concerning physical phenomena in larger tokamak facilities as a result of implementation of the proposed charged particle, gamma and neutron detectors,-improvement of technology in the range of important subject concerning the application of new kind of optical fiber sensors based on polyimides and high quality crystals for neutron detection.It is assumed that the first steps will be a better recognition of the demands for charged particles, gammas and neutrons diagnostics at tokamak, gaining the knowledge about the technical details concerning implementation of the diagnostics in real experimental conditions and then choosing the best suitable detectors (optical fiber sensors and crystals). Then the irradiation of the strain, temperature and radiation optical fiber and crystal sensors with different kinds of radiation using especially 14 MeV neutrons and measuring and recognizing of the induced effects. Parallel we are going to investigate samples produced from the crystal and glasses materials for their changes under charge particles, gammas and neutron radiation.After drawing conclusion from the first tests and analyzing the real needs in detail the improved detectors will be designed and fabricated and the next experimental session will be carried on. Simultaneously, the improving works with the main goal of obtaining the possible great spectral resolution will be carried on.

WORK PLANThe realization of the whole project is planned for three years and the tasks will be scheduled as follows:The first year: getting in touch with the laboratories dealing with the spectrometry of the fusion charged particles, gammas and neutrons, choosing the proper detectors for spectrometry, recognition the problems connected with fabrication of polyimide optical fiber and crystal detectors, finding suitable materials (doping appropriately to the kind of radiation) for the detectors (sensors). The second year: organization of the first experimental session at tokamak, testing different detectors, fabrication the improved versions of optical fiber detectors.The third year: testing the improved version of the improved polyimide optical fibre detectors (sensors), diagnosing plasmas with the use of the matrix detectors.

Documents

Application of quartz glass, polyimide optical fiber sensors and crystal detectors to measurement of charged- particles, gamma and neutron dose in tokamak