Target unit for radiation test of materials under bremsstrahlung of electron accelerator
There is a necessity to provide an immobilization of the long-lived radioactive waste into radiation-resistant structure (a cement matrix, container capsule, geological disposal environment and so on) for it safely disposal. The material of the every of these barriers should have resistance correspo...
Saved in:
| Published in: | Вопросы атомной науки и техники |
|---|---|
| Date: | 2001 |
| Main Authors: | , , , , , , , |
| Format: | Article |
| Language: | English |
| Published: |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2001
|
| Online Access: | https://nasplib.isofts.kiev.ua/handle/123456789/79031 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Journal Title: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Cite this: | Target unit for radiation test of materials under bremsstrahlung of electron accelerator / L.V. Yeran, S.P. Karasyov, R.I. Pomatsalyuk, S.Yu. Sayenko, V.A. Shevchenko, I.N. Shlyakhov, A.Eh. Tenishev, V.L. Uvarov // Вопросы атомной науки и техники. — 2001. — № 5. — С. 206-208. — Бібліогр.: 5 назв. — англ. |
Institution
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-79031 |
|---|---|
| record_format |
dspace |
| spelling |
Yeran, L.V. Karasyov, S.P. Pomatsalyuk, R.I. Sayenko, S.Yu. Shevchenko, V.A. Shlyakhov, I.N. Tenishev, A.Eh. Uvarov, V.L. 2015-03-24T18:51:56Z 2015-03-24T18:51:56Z 2001 Target unit for radiation test of materials under bremsstrahlung of electron accelerator / L.V. Yeran, S.P. Karasyov, R.I. Pomatsalyuk, S.Yu. Sayenko, V.A. Shevchenko, I.N. Shlyakhov, A.Eh. Tenishev, V.L. Uvarov // Вопросы атомной науки и техники. — 2001. — № 5. — С. 206-208. — Бібліогр.: 5 назв. — англ. 1562-6016 PACS number: 81.70.-q https://nasplib.isofts.kiev.ua/handle/123456789/79031 There is a necessity to provide an immobilization of the long-lived radioactive waste into radiation-resistant structure (a cement matrix, container capsule, geological disposal environment and so on) for it safely disposal. The material of the every of these barriers should have resistance corresponding to the absorbed dose value up to 10⁸ Gy for the period of time up to 1000 years. The method of imitation exposure of the materials under bremsstrahlung of the high-current Linac was developed for prediction behavior and material selection. For realization of this method in a wide range of exposure conditions (by temperature, humidity, rate and amount of the doze) the special target unit was designed. It has a modular construction and includes two chambers for samples (one for exposure in liquid and another one – in the atmosphere) that are placed along the irradiation axis and integrated together spatially. Also, the target unit has plane-parallel ionization chamber for continuous monitoring of the photon flux intensity and absorbed doze. The copper thermistor is used as a temperature probe. The structure and characteristics of measurement channels are described as well. Work is supported by STCU under contract N 1580. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Target unit for radiation test of materials under bremsstrahlung of electron accelerator Мишенное устройство для радиационных испытаний материалов в поле тормозного излучения ускорителя электронов Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| spellingShingle |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator Yeran, L.V. Karasyov, S.P. Pomatsalyuk, R.I. Sayenko, S.Yu. Shevchenko, V.A. Shlyakhov, I.N. Tenishev, A.Eh. Uvarov, V.L. |
| title_short |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| title_full |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| title_fullStr |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| title_full_unstemmed |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| title_sort |
target unit for radiation test of materials under bremsstrahlung of electron accelerator |
| author |
Yeran, L.V. Karasyov, S.P. Pomatsalyuk, R.I. Sayenko, S.Yu. Shevchenko, V.A. Shlyakhov, I.N. Tenishev, A.Eh. Uvarov, V.L. |
| author_facet |
Yeran, L.V. Karasyov, S.P. Pomatsalyuk, R.I. Sayenko, S.Yu. Shevchenko, V.A. Shlyakhov, I.N. Tenishev, A.Eh. Uvarov, V.L. |
| publishDate |
2001 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Мишенное устройство для радиационных испытаний материалов в поле тормозного излучения ускорителя электронов |
| description |
There is a necessity to provide an immobilization of the long-lived radioactive waste into radiation-resistant structure (a cement matrix, container capsule, geological disposal environment and so on) for it safely disposal. The material of the every of these barriers should have resistance corresponding to the absorbed dose value up to 10⁸ Gy for the period of time up to 1000 years. The method of imitation exposure of the materials under bremsstrahlung of the high-current Linac was developed for prediction behavior and material selection. For realization of this method in a wide range of exposure conditions (by temperature, humidity, rate and amount of the doze) the special target unit was designed. It has a modular construction and includes two chambers for samples (one for exposure in liquid and another one – in the atmosphere) that are placed along the irradiation axis and integrated together spatially. Also, the target unit has plane-parallel ionization chamber for continuous monitoring of the photon flux intensity and absorbed doze. The copper thermistor is used as a temperature probe. The structure and characteristics of measurement channels are described as well.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/79031 |
| citation_txt |
Target unit for radiation test of materials under bremsstrahlung of electron accelerator / L.V. Yeran, S.P. Karasyov, R.I. Pomatsalyuk, S.Yu. Sayenko, V.A. Shevchenko, I.N. Shlyakhov, A.Eh. Tenishev, V.L. Uvarov // Вопросы атомной науки и техники. — 2001. — № 5. — С. 206-208. — Бібліогр.: 5 назв. — англ. |
| work_keys_str_mv |
AT yeranlv targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT karasyovsp targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT pomatsalyukri targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT sayenkosyu targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT shevchenkova targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT shlyakhovin targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT tenishevaeh targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT uvarovvl targetunitforradiationtestofmaterialsunderbremsstrahlungofelectronaccelerator AT yeranlv mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT karasyovsp mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT pomatsalyukri mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT sayenkosyu mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT shevchenkova mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT shlyakhovin mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT tenishevaeh mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov AT uvarovvl mišennoeustroistvodlâradiacionnyhispytaniimaterialovvpoletormoznogoizlučeniâuskoritelâélektronov |
| first_indexed |
2025-11-27T04:07:15Z |
| last_indexed |
2025-11-27T04:07:15Z |
| _version_ |
1850798634734452736 |
| fulltext |
TARGET UNIT FOR RADIATION TEST OF MATERIALS UNDER
BREMSSTRAHLUNG OF ELECTRON ACCELERATOR
L.V. Yeran, S.P. Karasyov, R.I. Pomatsalyuk, S.Yu. Sayenko, V.A. Shevchenko,
I.N. Shlyakhov, A.Eh. Tenishev, V.L. Uvarov
NSC KIPT, Kharkov, Ukraine
uvarov@kipt.kharkov.ua
There is a necessity to provide an immobilization of the long-lived radioactive waste into radiation-resistant struc-
ture (a cement matrix, container capsule, geological disposal environment and so on) for it safely disposal. The ma-
terial of the every of these barriers should have resistance corresponding to the absorbed dose value up to 108 Gy for
the period of time up to 1000 years. The method of imitation exposure of the materials under bremsstrahlung of the
high-current Linac was developed for prediction behavior and material selection. For realization of this method in a
wide range of exposure conditions (by temperature, humidity, rate and amount of the doze) the special target unit
was designed. It has a modular construction and includes two chambers for samples (one for exposure in liquid and
another one – in the atmosphere) that are placed along the irradiation axis and integrated together spatially. Also, the
target unit has plane-parallel ionization chamber for continuous monitoring of the photon flux intensity and ab-
sorbed doze. The copper thermistor is used as a temperature probe. The structure and characteristics of measurement
channels are described as well.
PACS number: 81.70.-q
1 INTRODUCTION
The main goal of imitation exposure of the materials
that are used for the immobilization of radionuclides is a
creation of absorbed doze up to 108 Gy in investigated
samples during acceptable period of the time (no more
than 1 year) at monitoring parameters of radiation ef-
fect. These parameters in the first instance are an ab-
sorbed doze rate and a temperature of the samples.
Namely these parameters define the annealing rate of
the radiation defects, and thus, representability of the re-
sults obtained. It is easy to make sure that the radiation
heating of samples is no more than ~10° under absorbed
doze rate noted above, i.e. contribution of the tempera-
ture to annealing of defects in the process of imitation
exposure can be ignored. However, the specified param-
eters and also spectral characteristics of radiation are ba-
sic objects of metrological accompaniment of the imita-
tion exposure.
The gamma-ray unit with radionuclide sources (basi-
cally, Со-60) is a traditional radiation source for testing
in doze range up to 108 Gy. The advantage of such tests
is stability of influence conditions to the sample. There-
with, the setup with activity up to 1 MCi is needed to
provide the absorbed doze rate (ADR) about 10 Gy/s
[2]. The electron accelerator can provide the same con-
ditions with converting its beam to bremsstrahlung (BR)
[3]. The value of the BR ADR in a sample of about
10 Gy/s for electrons with the energy 10 MeV is
reached by converting a beam with the power 10 kW,
that corresponds to parameters of modern industrial ac-
celerators (see, for example, [4]). A possibility of the
electron energy and flux control provides an expansion
of range of the influence parameters to the sample dur-
ing its test.
The results of development of the special target unit
for sample exposure under bremsstruhlung of high-cur-
rent electron accelerator are presented in this report.
2 TARGET UNIT COMPONENTS
2.1. The target unit (TU) has a parallelepiped shape
and consists of three chambers (Fig. 1).
Beam
scanning
axis
Iion T° ,C
2
1
3
4
5
Fig. 1. TU components.
Upper hermetically sealed chamber 1 is designed for
placement of samples, being irradiated in liquid (throat
2 is made to pass samples in liquid), and central cham-
ber 3 – in air. The free-air ionization chamber (IC-1) is
placed in volume 4 for continuously monitoring of pho-
ton stream through the samples. The passage with tube 5
for the ionization chamber feed and signal cables is
made in ceramic insulator.
2.2. The linear sweep of the electron beam within
limits of the output accelerator window is performed by
the electromagnet EM (see Fig. 2).
The scanned beam is directed to the converter of
bremsstruhlung C, that is a plate from material with a
high atomic number (tantalum, tungsten) and placed
into a tank being cooled by the running water. The
thickness of the water layer under the plate is chosen so
that the part of accelerated electrons passed through the
plate is absorbed in this layer. The TU is placed under
the bottom of the tank symmetrically to the line of the
beam scan. An irregularity of the photon flow density
on a surface of the TU is defined by distribution of the
electron flow density on a surface C, and also by the
width of TU and typically is less than ±5%.
206
mailto:uvarov@kipt.kharkov.ua
e-
A
EM
C
Н2О
TU
γ
Fig. 2. TU geometry placement.
3 COMPUTER SIMULATION
As known, granite is the promising geological envi-
ronment for radioactive waste disposal [4]. Therefore,
the samples from granite (that consists of more than
70% of SiO2) was chosen as one from objects to study.
The preliminary calculations showed that replacement
of the real matrix from granite to pure SiO2 when simu-
lating the radiation effect gives the results varied no mo-
re than 3%, but the calculation time is reduced conside-
rably in this case. Version of the TU analyzed with a
method of the computer simulation is presented in
Fig. 3.
e- e-
dН2О
dAIR
dSiО2
dCONV
dSiО2
dIC
Fig. 3. Geometry and parameters of simulation.
dconv,cm dH2O,cm dair,cm dSiO2,cm dIC,cm
2 15 5 2 2
The calculations were made for three values of the ac-
celerated electron energy: 10, 15 and 20 MeV with the
average beam current 1mA (see Table 1). Analysis of
the data obtained shows that the version of the TU under
consideration provided an irradiation of the samples by
“pure” braking photon flow in all the range of the accel-
erated electron energy.
Table 1. Simulation results
Electron energy, MeV
10 15 20
Electron energy flux, kW 10 15 20
Number of absorbed elec-
trons, % in converter
in water filter
99.5
-
92.79
6.92
49.07
50.73
Photon energy flux at TU,
kW
1.07 2.76 5.08
Average energy of photons,
MeV
0.82 1.12 1.44
Absorbed power P of pho-
ton radiation in SiO2, W
16.32 50.18 110.8
Ionization current I in IC, µ
А
60 191 419
k=I/P, µА/W 3.64 3.80 3.78
The average photon energy Еγ by spectrum occurs
near the values for such representative components of
the radioactive waste as Cs-137 (Еγ=0.662 MeV) and
Со-60 (Еγ=1.25 MeV), and ADR in SiO2 is ≥10 Gy/s,
that satisfy the conditions of the imitation exposure.
Close linear dependence of ionization current on ab-
sorbed power of the braking photon radiation in SiO2 is
observed in the investigated energy range of accelerated
electrons. That can be explained by realization of the
electron balance conditions for the given relation of
electron energy and also the thickness of the water filter
and irradiated samples [5]. This result gives a reason to
carry out continuous nondestructive monitoring of the
absorbed doze in irradiated samples from ionization
charge in IC.
4 MEASUREMENT CHANNEL
4.1. In the context of the results noted above the
measurement channel for the TU (Fig. 4.) was develo-
ped and designed for on-line monitoring of absorbed
doze and ADR of the photon radiation and also for mea-
suring the temperature of samples under irradiation. The
channel provides measurements both in the stand-alone
mode and in the remote mode controlling by computer
using RS-232 interface.
Measurement circuit
of photon radiation
parameters
Temperature
measurement circuit
IC-1
ТР-1
CPU
module
Power supply
TU
Fig. 4. Block-diagram of measurement channel.
The channel includes two measurement circuits. The
free-air ionization chamber IC-1 is used as a primary
sensor in the measurement circuit of the braking radia-
tion parameters. The thermal probe TP-1 is used in the
measurement circuit of the sample temperature.
4.2 Technical data
The measurement channel of photon radiation:
- current range of the IC-1, µА - 5…5000
- relative measurement error of the
IC-1 current, % - ≤ 3
The measurement channel of the sample tempera-
ture:
- temperature range, °С - 0…80
- relative measurement error, % - ≤ 3
The power supply produces a stabilized DC voltage
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №5.
Серия: Ядерно-физические исследования (39), с. 207-208.
207
+/-15 V to feed the measurement circuits and +5 V to
feed the central-processing unit (CPU) module.
4.3 The measurement circuit of the photon radiation
parameters
A signal from the ionization chamber IC-1 (Fig. 5)
directs to the input of the current-to-voltage converter
(CVC). The voltage with the amplitude proportional to
the input current is produced at the output of the CVC.
Then a signal through the optoisolation and amplifier
goes to the input 1 of the analog-to-digital converter
(ADC). The CVC is made on a base of the operational
amplifier (OA) type AD711. The resistors of type
С2-29ОС ±0.5% are used to increase the time and tem-
perature stability.
IC-1 CVC Opto-
isolation
Amplifier
Output U1
Fig. 5. Block-diagram of measurement circuit of
ionization current.
4.4 The temperature measurement circuit
The thermal probe TP-1 (Fig. 6.) is feed from the
stable current generator with a magnitude of 1 mA. A
signal from the thermistor TP-1 is going to the input of
the thermostable differential amplifier (DA). The input
of the DA has the filter for suppression of an HF noise.
The DA is made on a base of OA type AD623 with the
resistors С2-29.
The CVC, the stable current generator and DA are
placed into the thermostat from the foam plastic.
ТР-1 Differential
amplifier
Opto-
isolation
Amplifier
Output U2
Current
generator
Fig. 6. Block-diagram of temperature measurement
circuit.
4.5 CPU module
The CPU module (Fig. 7) consists of the following
components:
- ADC;
- CPU;
- data memory (RAM);
- program memory(ROM);
- indication module (IM);
- control keypad (CK);
- level translator of the serial interface (LT).
ADC
CPU
Display unit
Keypad
ROM
RAM
RS-232 level
translator
INPUT1
INPUT2
To remote
computer
Fig. 7. Block-diagram of the CPU module.
The basic functions performed by the CPU module
are:
- conversion of analogue signals from the measure-
ment circuit to the digital code by the ADC;
- storing the results of the measurements and con-
verting them to physical units;
- measurement data display; control of the operation
mode by using the keypad;
- data exchange between the CPU module and re-
mote computer using a serial interface RS-232.
4.6 Measurement procedure
After starting a measurement the CPU produces the
control signals for the ADC during 10 ms with 1 s peri-
od. The scan rate of ADC is 10 kHz. The values of ana-
logue signals converted to the digital code from one of
the measurement circuits are stored into the data me-
mory RAM. Then these data are averaged, converted to
physical units and output to the display unit. Every se-
cond the measurement circuit is switched to another
one. One time per second the increment of the measu-
rement values are calculated and stored. The timer is
started from the begining of measurement process for
calculation of measurement time. The measurement pro-
cess is stopped after a corresponded key has been
pressed on the keypad.
There are two mode of the CPU module operation:
from the keypad control (stand-alone mode) and under
control from the remote computer using a serial inter-
face RS-232. In last case the data transfer to the remote
computer.
5 CONCLUSION
The special target unit to provide radiation tests of
the material samples in bremsstrahlung field of the elec-
tron accelerator has been developed with the follow pa-
rameters range:
- absorbed doze rate of photon radiation, Gy/s- 1…100;
- absorbed doze, Gy - 103...1010;
- average photon energy , MeV - 0.8…1.4;
- samples temperature, Т°С - 0...80.
The device has the measurement channel linked to
the remote computer that provides on-line monitoring of
the photon radiation parameters and temperature of the
samples.
Work is supported by STCU under contract N 1580.
REFERENCES
1. N.P.Dikiy, S.Yu.Sayenko, V.L.Uvarov, E.P.Shevya-
kova. Application of Nuclear-Physics Methods for
Studying the Radionuclide Transport in Granite Rocks
// Voprosy atomnij Nauki i Tekhniki. Seriya:
“Yaderno-Fizicheskiye issledovaniya” (36). 2000, №
2, p. 54-57.
2. A.K.Krasin et al. Powerful gamma-setup UGU-200 //
Atomnaya Ehnergiya. 1971, v. 31, N. 3, p. 205-207.
3. V.V.Kluyev et al. Nondistructive Control with the
High-Energy Sources. Moscow: Energoatomizdat,
1989, 176 p. (in Russian).
4. Z.M.Deconik et al. Investigation of Possibility of Ra-
208
dioactive Waste Disposal in Deep Geological Forma-
tion // Bulletin of Ecological State of Chernobyl Zone.
1999, v. 13, p. 64-66 (in Ukrainian).
5. V.Vexler et al. Ionization Methods for Investigation of
Radiations. Moscow: GITTL, 1949, 424 p.
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2001. №5.
Серия: Ядерно-физические исследования (39), с. 209-208.
209
|