RU2466428C2 - Metal-containing plastic scintillator - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: polystyrene-based plastic scintillator contains luminescent additives and a metal-containing compound, wherein the luminescent additives are a nanostructure filler consisting of links corresponding to a primary and a secondary luminophore, and the metal-containing compound is a compound selected from self-organising nanostructure organoelement compounds of general formula C₂₄H₂₃O₆S₃Si₃Me, where Me denotes Fu or Tb, with the following ratio of components, wt %: nanostructure filler 1.0-2.0; metal-containing compound 1.0-10.0; polystyrene - the balance.

EFFECT: high efficiency of detecting gamma-quanta with energy of 20-200 keV and high light output.

4 cl, 2 dwg

Description

The invention relates to the field of creating materials for scintillation technology, in particular to the creation of plastic scintillators with a high average atomic number and can be used in experimental installations and devices for recording low-energy gamma radiation (20-200 KeV).

Known plastic scintillator based on vinyl aromatic polymers and nanostructured filler [RF patent N2380726]. This scintillator has a light output relative to anthracene 100-110%, however, it does not contain metal-containing compounds. Therefore, the attenuation coefficient of gamma rays with an energy of 60 KeV for this scintillator does not exceed 0.2 cm ^-1 .

The closest in technical essence and the achieved result to the claimed scintillator is a plastic scintillator based on vinyl aromatic polymers (including polystyrene), including luminescent additives and a metal-containing compound from tin or lead alkylaryl compounds [USSR copyright certificate N1464706, cl. G01T 1/203, publ. 12/15/1992. Bull. No. 46]. The attenuation coefficient of gamma rays with an energy of 60 KeV for this scintillator reaches 0.3-0.4 cm ^-1 , however, the light output in this case is 35-45% of the light output of anthracene.

Most often, polystyrene is used as a vinylaromatic polymer for the polymer matrix of plastic scintillators due to its good optical properties, commercial availability and low price of both the polymer itself and the monomer for its production - styrene (B.V. Grinev, V.G. Senchishin. Plastic scintillators, 2003, Act, Kharkov, 324 p.).

The objective of the invention is to obtain a new plastic scintillator with increased detection efficiency of gamma rays with an energy of 20-200 keV and high light output.

The technical result that can be obtained by carrying out the invention: 1) the attenuation coefficient of gamma rays with an energy of 60 KeV is 1.5-2.5 times higher than that of a plastic scintillator without a metal-containing compound; 2) the light output of the new plastic scintillator is 60-75% relative to the light output of anthracene.

The problem is solved in that a new plastic scintillator based on polystyrene has been created, including luminescent additives and a metal-containing compound, which differs from the known one in that, as luminescent additives, it contains a nanostructured filler, consisting of units corresponding to the primary and secondary phosphors, and as a metal-containing compound contains a compound selected from self-organizing nanostructured organoelement compounds of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Me, where Me means Eu or Tb, in the following ratio of components, wt.%:

nanostructured filler 1.0-2.0 metal compound 1.0-10.0 polystyrene rest

In particular, in the nanostructured filler, the units corresponding to the primary and secondary phosphors are the primary phosphor compounds - 2,2'-bitienyl (four units) and the secondary phosphor - 9,10-diphenylanthracene (one unit).

In particular, the self-organizing nanostructured organoelement compound is C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu or C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb.

An increase in the efficiency of detecting gamma rays is achieved by increasing the average atomic number of a plastic scintillator based on polystyrene and a nanostructured filler due to the introduction of a metal with a large atomic number ( ¹⁵³ Eu or ¹⁵⁹ Tb). The high light output of a plastic scintillator based on polystyrene and a nanostructured filler decreases slightly, since the long-wavelength absorption of 5- (trimethylsilyl) thiophene-2-carbonyl ligand lies in the region of 230-250 nm and does not overlap with the luminescence spectra of polystyrene (280-350 nm ) and nanostructured filler (400-500 nm). A slight decrease in light output with increasing concentration of the metal-containing compound is explained by a decrease in the proportion of polystyrene and fluctuations in the density of the matrix caused by the high content of the metal-containing compound.

Self-organizing nanostructured organoelement compounds of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Me, where Me = Eu or Tb (see Fig. 1), are obtained by reacting 5- (trimethylsilyl) thiophene-2-carboxylic acid with acetate of the corresponding metal ( europium or terbium) according to the ligand exchange reaction. Examples of such reactions are described in Chem. Mater. 1998, v. 10, No. 1, p. 286-296. Examples of the preparation of organosilicon derivatives of thiophenecarboxylic acid are described in Langmuir, 2009, v.25, No. 16, p.9270-9284.

The nanostructured filler contains primary and secondary phosphors connected by silicon atoms into nanoscale branched macromolecules. In this case, the primary phosphor is selected from the group of compounds in which the maximum of the long-wavelength band of the absorption spectrum is in the range from 270 to 350 nm and the quantum fluorescence yield is not less than 5%, and the secondary phosphor is selected from the group of compounds in which the maximum of the long-wavelength band of the absorption spectrum is in the range from 330 to 400 nm and the quantum fluorescence yield of at least 30%.

Nanostructured filler is obtained using at least one of the reactions of organometallic synthesis (Suzuki, Kumada, Stille, Ulman), as well as the interaction of chloro or alkoxysilanes with lithium or organomagnesium derivatives. Examples of such reactions are described in:

1. Proceedings of the Academy of Sciences, Chemical Series, 2005, No. 3, p.673;

2. Mendeleev Communications, 2007, v. 17, No. 1, p. 34-36;

3. Chem. Mater., 2009, v.21, No. 3, p. 447-455.

Branched oligoarylsilanes can be used as nanostructured fillers, for example, those described in RF patent No. 2396290 or polyaryl silane dendrimers described in RF patent No. 2353629. Preferred is a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), the structural formula of which is shown in Figure 2.

The scintillator blank is prepared by mixing a nanostructured filler and a nanostructured organoelement compound with a polymer selected as a base in a twin-screw mixer with a return channel (at a temperature of 180 ° C and a screw speed of 600 rpm). Then by pressing (at a plate temperature of 180 ° C), PS samples with a diameter of 25 mm and a height of 10 mm are obtained. The surface of the sample is carefully polished.

The attenuation coefficient of gamma rays and the light output of a plastic scintillator are measured on a calibrated amplitude spectrometer.

Figure 1 shows the structural formula of self-organizing nanostructured organoelement compounds of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Me, where Me = Eu or Tb.

Figure 2 presents the structural formula of a nanostructured filler, consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit).

The invention is illustrated by the following examples.

Example 1

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 1% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 98% of the mass.

The measured attenuation coefficient of gamma rays is 0.22 cm ^-1 .

The measured light yield of the PS sample is 60%, relative to the light output of anthracene.

Example 2

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 2.5% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 96.5% of the mass.

The measured attenuation coefficient of gamma rays is 0.29 cm ^-1 .

The measured light yield of the PS sample is 58%, relative to the light output of anthracene.

Example 3

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 5% by weight;

nanostructured filler - 1% of the mass;

polystyrene - 94% of the mass.

The measured attenuation coefficient of gamma rays is 0.36 cm ^-1 .

The measured light yield of the PS sample is 53%, relative to the light output of anthracene.

Example 4

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 10% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 89% of the mass.

The measured attenuation coefficient of gamma rays is 0.43 cm ^-1 .

The measured light yield of the PS sample is 47%, relative to the light output of anthracene.

Example 5

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 1% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 98% of the mass.

The measured attenuation coefficient of gamma rays is 0.24 cm ^-1 .

The measured light yield of the PS sample is 70%, relative to the light output of anthracene.

Example 6

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 2.5% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 96.5% of the mass.

The measured attenuation coefficient of gamma rays is 0.36 cm ^-1 .

The measured light yield of the PS sample is 68%, relative to the light output of anthracene.

Example 7

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb — 5% by weight;

nanostructured filler - 1% of the mass;

polystyrene - 94% of the mass.

The measured attenuation coefficient of gamma rays is 0.44 cm ^-1 .

The measured light yield of the PS sample is 64%, relative to the light output of anthracene.

Example 8

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 10% of the mass;

nanostructured filler - 1% of the mass;

polystyrene - 89% of the mass.

The measured attenuation coefficient of gamma rays is 0.53 cm ^-1 .

The measured light yield of the PS sample is 55%, relative to the light output of anthracene.

Example 9

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 1% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 97% of the mass.

The measured attenuation coefficient of gamma rays is 0.22 cm ^-1 .

The measured light yield of the PS sample is 73%, relative to the light output of anthracene.

Example 10

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 2.5% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 95.5% of the mass.

The measured attenuation coefficient of gamma rays is 0.29 cm ^-1 .

The measured light yield of the PS sample is 71%, relative to the light output of anthracene.

Example 11

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 5% by weight;

nanostructured filler - 2% of the mass;

polystyrene - 93% of the mass.

The measured attenuation coefficient of gamma rays is 0.36 cm ^-1 .

The measured light yield of the PS sample is 64%, relative to the light output of anthracene.

Example 12

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu - 10% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 88% of the mass.

The measured attenuation coefficient of gamma rays is 0.43 cm ^-1 .

The measured light yield of the PS sample is 56%, relative to the light output of anthracene.

Example 13

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 1% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 97% of the mass.

The measured attenuation coefficient of gamma rays is 0.24 cm ^-1 .

The measured light yield of the PS sample is 85%, relative to the light output of anthracene.

Example 14

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 2.5% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 95.5% of the mass.

The measured attenuation coefficient of gamma rays is 0.36 cm ^-1 .

The measured light yield of the PS sample is 82%, relative to the light output of anthracene.

Example 15

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb — 5% by weight;

nanostructured filler - 2% of the mass;

polystyrene - 93% of the mass.

The measured attenuation coefficient of gamma rays is 0.44 cm ^-1 .

The measured light yield of the PS sample is 78%, relative to the light output of anthracene.

Example 16

Using a metal-containing compound of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb and a nanostructured filler consisting of a primary phosphor - 2,2'-bitienyl (four units) and a secondary phosphor - 9,10-diphenylanthracene (one unit), are made a sample of a plastic scintillator of the following composition:

the metal-containing compound C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb - 10% of the mass;

nanostructured filler - 2% of the mass;

polystyrene - 88% of the mass.

The measured attenuation coefficient of gamma rays is 0.53 cm ^-1 .

The measured light yield of the PS sample is 66%, relative to the light output of anthracene.

Claims (4)

1. A polystyrene-based plastic scintillator comprising luminescent additives and a metal-containing compound, characterized in that as luminescent additives it contains a nanostructured filler consisting of units corresponding to primary and secondary phosphors, and as a metal-containing compound contains a compound selected from self-organizing organo-organizing compounds of the general formula C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Me, where Me is Eu or Tb, the following ratio of components of s, wt.%:
nanostructured filler 1.0-2.0 metal compound 1.0-10.0 polystyrene rest 2. The plastic scintillator according to claim 1, characterized in that in the nanostructured filler, the links corresponding to the primary and secondary phosphors are the primary phosphor compounds - 2,2'-bithienyl (four units) and the secondary phosphor - 9,10-diphenylanthracene (one link). 3. The plastic scintillator according to claim 1, characterized in that the self-organizing nanostructured organoelement compound is C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Eu. 4. The plastic scintillator according to claim 1, characterized in that the self-organizing nanostructured organoelement compound is C ₂₄ H ₂₃ O ₆ S ₃ Si ₃ Tb.

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