An estimate of ⁴⁷Sc photonuclear yield in a production target
⁴⁷Sc is considered as a promising beta-emitter for cancer immunotherapy. For its carrier-free production, the ⁴⁸Ti(γ,p) ⁴⁷ Sc reaction in the field of bremsstrahlung radiation of an electron accelerator can be used. On the basis of developed analytical model and a double-foil activation technique, t...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2020
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| Цитувати: | An estimate of ⁴⁷Sc photonuclear yield in a production target / N.P. Dikiy, Yu.V. Lyashko, V.A. Shevchenko, A.Eh. Tenishev, V.L. Uvarov, A.A. Zakharchenko // Problems of atomic science and tecnology. — 2020. — № 3. — С. 158-162. — Бібліогр.: 15 назв. — англ. |
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irk-123456789-1945472023-11-27T15:40:49Z An estimate of ⁴⁷Sc photonuclear yield in a production target Dikiy, N.P. Lyashko, Yu.V. Shevchenko, V.A. Tenishev, A.Eh. Uvarov, V.L. Zakharchenko, A.A. Application of nuclear methods ⁴⁷Sc is considered as a promising beta-emitter for cancer immunotherapy. For its carrier-free production, the ⁴⁸Ti(γ,p) ⁴⁷ Sc reaction in the field of bremsstrahlung radiation of an electron accelerator can be used. On the basis of developed analytical model and a double-foil activation technique, the main characteristics of the photonuclear isotope production and optimal dimensions of a production target have been established. The measured photonuclear yield of ⁴⁷Sc and dominant scandium admixtures in thin foils of natural titanium in the electron energy range of 35 to 95 MeV enabled to specify the available data on the cross-section of the ⁴⁸Ti(γ,p)⁴⁷Sc reaction. Using those results, the gross and specific activity of ⁴⁷Sc in the cylindrical titanium targets of optimal size were calculated by a simulation technique. The comparison of capacity of the photonuclear method of the ⁴⁷Sc production with other techniques is carried out. ⁴⁷Sc вважається перспективним бета-емітером в імунотерапії раку. Для виробництва ізотопу без носія може бути використана реакція ⁴⁸Ti (γ,p)⁴⁷Sc у полі гальмівного випромінення прискорювача електронів. На основі розробленої аналітичної моделі і методу сумісної активації двох фольг встановлені основні характеристики фотоядерного виробництва ізотопів та оптимальні розміри технологічної мішені. Одержані експериментальні дані щодо виходу ⁴⁷Sc і основних домішкових ізотопів скандію в тонких фольгах з природного титану в діапазоні значень енергії електронів 35…95 МеВ дозволяють уточнити наявні дані щодо перетину реакції ⁴⁸Ti(γ,p)⁴⁷Sc. На основі цих результатів методом моделювання розраховані загальна і питома активність ⁴⁷Sc у циліндричних мішенях з титану оптимального розміру. Проведено порівняння продуктивності фотоядерної технології виробництва ⁴⁷Sc з іншими методами. ⁴⁷Sc считается перспективным бета-эмиттером в иммунотерапии рака. Для производства изотопа без носителя может быть использована реакция ⁴⁸ Ti (γ,p)⁴⁷ Sc в поле тормозного излучения ускорителя электронов. На основе разработанной аналитической модели и метода совместной активации двух фольг установлены основные характеристики фотоядерного производства изотопов и оптимальные размеры технологической мишени. Полученные экспериментальные данные по выходу ⁴⁷Sc и основных примесных изотопов скандия в тонких фольгах из природного титана в диапазоне значений энергии электронов 35…95 МэВ позволяют уточнить имеющиеся данные по сечению реакции ⁴⁸Ti(γ,p)⁴⁷Sc. На основе этих результатов методом моделирования рассчитаны общая и удельная активность ⁴⁷Sc в цилиндрических мишенях из титана оптимальных размеров. Проведено сравнение производительности фотоядерной технологии производства ⁴⁷Sc с другими методами. 2020 Article An estimate of ⁴⁷Sc photonuclear yield in a production target / N.P. Dikiy, Yu.V. Lyashko, V.A. Shevchenko, A.Eh. Tenishev, V.L. Uvarov, A.A. Zakharchenko // Problems of atomic science and tecnology. — 2020. — № 3. — С. 158-162. — Бібліогр.: 15 назв. — англ. 1562-6016 PACS: 07.05.Tr, 41.50.+h; 41.75.Fr; 78.70.En http://dspace.nbuv.gov.ua/handle/123456789/194547 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| language |
English |
| topic |
Application of nuclear methods Application of nuclear methods |
| spellingShingle |
Application of nuclear methods Application of nuclear methods Dikiy, N.P. Lyashko, Yu.V. Shevchenko, V.A. Tenishev, A.Eh. Uvarov, V.L. Zakharchenko, A.A. An estimate of ⁴⁷Sc photonuclear yield in a production target Вопросы атомной науки и техники |
| description |
⁴⁷Sc is considered as a promising beta-emitter for cancer immunotherapy. For its carrier-free production, the ⁴⁸Ti(γ,p) ⁴⁷ Sc reaction in the field of bremsstrahlung radiation of an electron accelerator can be used. On the basis of developed analytical model and a double-foil activation technique, the main characteristics of the photonuclear isotope production and optimal dimensions of a production target have been established. The measured photonuclear yield of ⁴⁷Sc and dominant scandium admixtures in thin foils of natural titanium in the electron energy range of 35 to 95 MeV enabled to specify the available data on the cross-section of the ⁴⁸Ti(γ,p)⁴⁷Sc reaction. Using those results, the gross and specific activity of ⁴⁷Sc in the cylindrical titanium targets of optimal size were calculated by a simulation technique. The comparison of capacity of the photonuclear method of the ⁴⁷Sc production with other techniques is carried out. |
| format |
Article |
| author |
Dikiy, N.P. Lyashko, Yu.V. Shevchenko, V.A. Tenishev, A.Eh. Uvarov, V.L. Zakharchenko, A.A. |
| author_facet |
Dikiy, N.P. Lyashko, Yu.V. Shevchenko, V.A. Tenishev, A.Eh. Uvarov, V.L. Zakharchenko, A.A. |
| author_sort |
Dikiy, N.P. |
| title |
An estimate of ⁴⁷Sc photonuclear yield in a production target |
| title_short |
An estimate of ⁴⁷Sc photonuclear yield in a production target |
| title_full |
An estimate of ⁴⁷Sc photonuclear yield in a production target |
| title_fullStr |
An estimate of ⁴⁷Sc photonuclear yield in a production target |
| title_full_unstemmed |
An estimate of ⁴⁷Sc photonuclear yield in a production target |
| title_sort |
estimate of ⁴⁷sc photonuclear yield in a production target |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2020 |
| topic_facet |
Application of nuclear methods |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/194547 |
| citation_txt |
An estimate of ⁴⁷Sc photonuclear yield in a production target / N.P. Dikiy, Yu.V. Lyashko, V.A. Shevchenko, A.Eh. Tenishev, V.L. Uvarov, A.A. Zakharchenko // Problems of atomic science and tecnology. — 2020. — № 3. — С. 158-162. — Бібліогр.: 15 назв. — англ. |
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Вопросы атомной науки и техники |
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ISSN 1562-6016. ВАНТ. 2020. №3(127) 158
AN ESTIMATE OF 47Sc PHOTONUCLEAR YIELD
IN A PRODUCTION TARGET
N.P. Dikiy, Yu.V. Lyashko, V.A. Shevchenko, A.Eh. Tenishev,
V.L. Uvarov, A.A. Zakharchenko
National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine
E-mail: uvarov@kipt.kharkov.ua
47Sc is considered as a promising beta-emitter for cancer immunotherapy. For its carrier-free production, the
48Ti(,p)47Sc reaction in the field of bremsstrahlung radiation of an electron accelerator can be used. On the basis of
developed analytical model and a double-foil activation technique, the main characteristics of the photonuclear iso-
tope production and optimal dimensions of a production target have been established. The measured photonuclear
yield of 47Sc and dominant scandium admixtures in thin foils of natural titanium in the electron energy range
of 35 to 95 MeV enabled to specify the available data on the cross-section of the48Ti(,p)47Sc reaction. Using those
results, the gross and specific activity of 47Sc in the cylindrical titanium targets of optimal size were calculated by a
simulation technique. The comparison of capacity of the photonuclear method of the 47Sc production with other
techniques is carried out.
PACS: 07.05.Tr, 41.50.+h; 41.75.Fr; 78.70.En
INTRODUCTION
47Sc (T1/2=3.35 d; E=162 keV; E=159.4 keV) is
believed as a promising beta-emitter for theragnostic
44Sc /47Sc pair (see e.g. [1]). The practical application of
47Sc is hampered by the absence of a high-capacity
technology with tolerant content of admixtures. In a
number of works, the possibility of that isotope carrier-
free production in the field of the bremsstrahlung radia-
tion of an electron accelerator via the 48Ti(,р)47Sc reac-
tion with threshold Еth=11.4 MeV was studied [2 - 4].
Commonly, estimation of capacity of such a tech-
nology is conducted on the ground of experimental data
on the 47Sc yield in a target of small size (weight) nor-
malized to the accelerator beam current [2]. Such an
approach includes the considerable uncertainties con-
nected with the accuracy of determination of target posi-
tion in a nonuniform flux of X-rays. So in Fig. 1, the
distribution of the 47Sc nuclei generated in a large cylin-
drical target from titanium with the X-ray beam having
end-point energy of 40 MeV, obtained by a simulation
technique, is presented. It is seen, that the reaction
products are essentially nonuniformly distributed over
the target volume.
It should be noted, that calculation of photonuclear
yield by a Monte-Carlo method, even using a HS calcu-
lation technique [5], is borne with the considerable ex-
penditure of time in view of a comparatively small reac-
tion cross-section. Moreover, such an approach requires
experimental checking, as the information sources give
sometimes different data on the reaction cross-section.
So for the 48Ti(,p)47Sc reaction, the referenced maxi-
mum of the cross-section makes about 30 [6], 13 [7],
and 7 mb [8, 9], respectively.
In [10] on the basis of a simplified analytical model
for the description of photonuclear isotope generation in
a thick target, the principal parameters of the process
have been introduced. In this work, the experimental
study of those characteristics for the 48Ti(,p)47Sc reac-
tion is conducted and the most appropriate value of the
reaction cross-section are specified. Using the data ob-
tained, an optimal size of a production target and its
activation regime are determined. So the capacity of the
technology is calculated, and also the yield of the Sc by-
products in a target from natural titanium is measured.
-2,5 -2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0 2,5
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
Width, cm
Fig. 1. Distribution of 47Sc nuclei in titanium target
irradiated with bremsstrahlung radiation
1. METHODS AND MATERIALS
1.1. A MODEL
As it is shown in [10], the volumetric distribution of
specific activity produced via a photonuclear i-reaction,
induced by a pencil electron beam with average current
I and particle energy Е0 for the irradiation period t, is
given by
0
0 2
0
2
2
0
1 exp( )( )( , , )
2 ( , )
exp ( )( ) ,
2 ( , )
ii
i
i
tY E IA E r z
e E z
r E z a
E z
(1)
0
,
0( ) ( ) ( ) ,
th i
E
A
i T i
E
NY E n E E dE
A (2)
0 ,0 0( , ) ( ) ,mE z z tg E (3)
where i is the decay constant, NA is the Avogadro
number, A is the average atomic mass of the target
material, T is its density, T is the relative content of
the isotope-target nuclei, ( )E is the linear photon
attenuation coefficient of photons with energy Е in the
ISSN 1562-6016. ВАНТ. 2020. №3(127) 159
target material, (E0,z) – is the standard radial deviation
of the photon flux density at a distance z from the con-
verter (z=0 corresponds to its rear plain), ( )i E is the
reaction cross-section, Eth,i is the threshold of the i-
reaction, ( )n E is the spectral density of X-rays nor-
malized to the one beam electron, and m is the most
probable angle of X-ray exit from a converter.
1.2. A DOUBLE-FOIL ACTIVATION TECHNIQUE
As it is evident from Eqs. (1) - (3), that the quantities
iY (E0), , and m determine the total activity and its
volumetric distribution in a target. iY (E0) denotes the
yield of isotope-product in a thin wide target overlap-
ping fully the photon flux and normal to its axis (a
photonuclear converter – PNC), normalized to the one
beam electron and to the unit of the mass thickness of
PNC. So the Yi quantity is called as a coefficient of
photonuclear conversion.
The Y, , and m values can be readily measured us-
ing a double-foil activation method [11]. It includes
joint activation of two stacked foils – PNC and a small
circular foil (S-target) by radius RS~(z), positioned
normally and axially symmetrically to the radiation flux
axis (Fig. 2).
Linac LU-40m
Converter
(4x1mm,Ta)
S-target
Exit window
Water in
Water out
Beam position
monitor
Water out
Water in
e-
PNC X
X
Fig. 2. Schematic of double-foil activation device
at exit of LU-40 electron Linac
Electron beam of a LU-40 accelerator was ejected
through an output window cooled with water [12]. On-
line monitoring of the beam axis position was conducted
using a beam position monitor. Via an input window
(stainless steel 0.3 mm thick), the beam was injected
into a target device comprises a bremsstrahlung con-
verter (four tantalum plates each of thickness 1 mm
cooled with water) followed by a pair of foils from natu-
ral titanium each of 50 µm in thickness, located axially
symmetrically to the beam axis. The first foil (PNC) is
by 25 mm in diameter when the second by 6 mm. Every
pair of foils was activated at a specified electron energy
Е0 in the range of 35…95 MeV with mean beam current
of 4 µA for 30 min. After cooling, the induced -spectra
of foils was measured using a Ge-detector. The ex-
panded uncertainty of the activity measurement did not
exceed 10%.
1.3. SIMULATION
For optimization of the target irradiation regime and
analysis of the experimental results on the yield of 47Sc
and by-products, the calculations were performed with
the use of a transport code GEANT4 and various data
on the cross-section of the photonuclear reactions on the
Ti isotopes.
In Fig. 3, the dependence of yield of the above-
threshold photons for the 48Ti(,р)47Sc reaction on the
thickness of a Ta-converter and the electron energy, is
presented. It is evident, that in the Е0 span of 30 to
100 MeV the converter thickness of 4 mm is close to
optimal.
1 2 3 4 5 6 7
0,2
0,4
0,6
0,8
1,0
1,2
N
E
>1
1.
63
M
eV
/ N
e b
ea
m
, q
ua
nt
um
pe
re
le
ct
ro
n
dc, mm
, 30 MeV
, 40 MeV
, 50 MeV
, 60 MeV
, 70 MeV
, 100 MeV
Fig. 3. Normalized yield of gammas with energy higher
11.4 MeV vs the converter thickness and electron
energy (solid curves correspond to a solid converter
when the separate points at dC =4 mm correspond
to its actual configuration)
The data on distribution of the photon flux density at
the converter exit obtained by modelling are given in
Fig. 4. It is obvious, that radial flux distribution is per-
fectly fitted with Gaussian.
-2,0 -1,5 -1,0 -0,5 0,0 0,5 1,0 1,5 2,0
0,0
0,1
0,2
0,3
0,4
Ebeam = 40 MeV;
output gammas,
E > 11.4 MeV
simulation
Gauss fit
ou
tp
ut
flu
x,
1
/c
m
2 /e
X-axis,cm
Model GaussAmp
Equation y=y0+A*exp(-0.5*((x-xc)/w)^2)
Plot eFlux,percm2_per_event
y0 0,00319 ± 7,92146E-4
xc -7,23367E-4 ± 0,0021
w 0,37049 ± 0,00238
A 0,37196 ± 0,00191
Reduced Chi-Sqr 1,46204E-5
R-Square (COD) 0,9991
Adj. R-Square 0,99903
a
0 10 20 30 40 50 60 70 80 90
0,00
0,01
0,02
0,03
0,04
N
i/
N
i
, degree
Ebeam = 40 MeV,
gammas, E > 11.4 MeV
max 7
m b
Fig. 4. Radial (a) and angular (b) distribution
of the above-threshold X-rays
2. RESULTS AND DISCUSSION
2.1. In Fig. 5, the results are presented on the de-
pendence of activity of the 47Sc and 46Sc isotopes in
PNC from natural titanium on electron energy Е0, ob-
ISSN 1562-6016. ВАНТ. 2020. №3(127) 160
tained experimentally and by simulation with the use of
cross-section data given in [6] and [7]. The calculations
with the [8] and [9] databases were not performed as
they provide obviously underestimated results.
35 40 45 50 55 60 65 70 75 80 85 90 95
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80 (Ti-48+Ti-49)->Sc-47
experiment
distance = 11 cm
talys
sherwood
A
PN
C
, k
B
q/
(
A
h
)
E0, MeV a
35 40 45 50 55 60 65 70 75 80 85 90 95
0,0
0,1
0,2
0,3
0,4
0,5
0,6
(Ti-47+Ti-48)->Sc-46
experiment
distance = 11 cm
talys
A
PN
C,
kB
q/
(
A
h
)
E0 , MeV b
Fig. 5. Dependence of 47Sc (a) and 46Sc (b) activity
in PNC on electron energy
The data on the 47Sc yield in the both foils of the
stack-targets are listed in Table 1 The results of simula-
tion were obtained using the cross-section data of the
TALYS package for the reactions 48Ti(,p)47Sc +
49Ti(,np)47Sc. The calculations showed, that the contri-
bution of second reaction in the span E0=35…95 MeV
does not exceed 2.3%. It is seen that at the lower border
of the E0 span, the calculated and experimental data are
satisfactory agreed within uncertainty of measurement.
At the same time with the rise of E0, a steady trend is
observed of overestimation of experimental results as
compared with ones using the TALYS database The
results on the specific activity of the small S-target ob-
tained experimentally ( exp
SA ) and by simulation tech-
nique ( calc
SA ) are given in Table 1 also, as well as the
estimates of maximum of the 47Sc specific activity maxA ,
located in the front surface of the target on the axis of
the radiation flux. The data was obtained with the use of
Eq. (1) and experimental values of exp
iY and .
2.2. As it follows from Eq. 1, the rate of the isotope
photonuclear generation at periphery of a cylindrical
target falls sharply as its diameter becomes higher than
FWHM of distribution of flux density of the above-
threshold photons (FWHM=2.354 δ), and the height of
the target (H) exceeds the free range of the photons
1( )iE , where Ei is the value of the photon energy cor-
responding the maximum of the reaction cross-section
max
i . The free range of the photons with energy
Еi=20 MeV in titanium makes 7.8 cm. So with due re-
gard to the values of δ listed in Table 1, a production
target from titanium by FWHM in diameter and up to 2
FWHM high can be considered as close to optimal.
The TALYS database was used in simulations as it pro-
vides a lower limit of the estimate of capacity of the
photonuclear technology for the 47Sc production
(Fig. 6).
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5
5,0
G
ro
ss
a
ct
iv
ity
, M
Bq
/(
A
h
)
H, mm
30 MeV
35 MeV
41 MeV
45 MeV
60 MeV
70 MeV
80 MeV
95 MeV
a
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
Sp
ec
ifi
c
ac
tiv
ity
, M
B
q/
(
A
h
g)
H, mm
30 MeV
35 MeV
41 MeV
45 MeV
60 MeV
70 MeV
80 MeV
95 MeV
b
Fig. 6. Dependence of gross (a) and specific (b) activity
of target from natural titanium on electron energy
and target height
The measured yield of the scandium isotopes at acti-
vation of targets from natural titanium is presented in
Fig. 7. It is evident, that the relative activity of 48Sc
(T1/2=44 h) at EOB is ~10% of the 47Sc activity and can
be decreased by cooling of a target. The relative yield of
46Sc (T1/2=84 d) makes ~1%.
30 40 50 60 70 80 90 100
E0, MeV
5
2
3
5
2
3
5
2
3
5
2
3
0.1
1.0
10.0
100.0
A
PN
C
, k
Bq
/
A
h
Sc
Sc
Sc
47
48
46
x
Fig. 7. Photonuclear yield of Sc isotopes in natural Ti
ISSN 1562-6016. ВАНТ. 2020. №3(127) 161
Table 1
Characteristics of 47Sc photonuclear generation in thin targets from natural titanium
E0,
MeV
δ, mm
(exp)
exp 510 ,iY
cm2/g
510 ,calc
iY
cm2/g
exp
,SA
MBq/(gAh) ,
calc
SA
MBq/(gAh) max ,
calc
A
MBq/(gAh)
35 6.4 0.99 0.89 0.20 0.19 0.21
40 4.3 1.51 1.47 0.62 0.54 0.71
45 4.4 1.92 1.68 0.76 0.59 0.98
48 4 2.15 1.87 1.03 0.73 1.16
60 3.5 2.80 2.41 1.63 1.22 1.96
70 3.1 3.18 2.73 2.31 1.72 2.84
80 3.3 3.56 2.99 2.81 1.96 3.63
95 2.2 4.14 3.29 5.51 2.63 7.31
The spectra of the Ti foils activated at various elec-
tron energies are presented in Fig. 8.
400 800 1200 1600 2000
energy (kev)
1
10
100
1000
10000
100000
co
un
ts
ju
vl
Sc48Sc46Sc46 Sc48Sc48Sc47
511
40K
a
400 800 1200 1600 2000
energy (kev)
1
10
100
1000
10000
100000
co
un
ts
ju
vl
Sc48Sc46Sc46 Sc48Sc48Sc47
511
44mSc
43K
44Sc
40K
b
Fig. 8. Spectra of Ti foils:
E0= 35 MeV (a), E0= 80 MeV (b)
CONCLUSIONS
The obtained experimental results on the yield of
47Sc via the 48Ti(,p)47Sc reaction show that the most
applicable data on the maximum of the reaction cross-
section (~13 mb) provides the TALYS database with
possible underestimation of about 10 to 15%.
In the electron energy (Е0) span of 35 to 95 MeV,
the gross activity of 47Sc rises approximately propor-
tional to Е0, when the specific activity ~E0
3. The relative
yield of the main Sc by-products in natural titanium at
EOB makes ~10% (48Sc) and ~1% (46Sc) to the activity
of 47Sc and can be decreased considerably by usage of a
target enriched in 48Тi. At activation of such a target by
11 mm in diameter and 22 mm in height (the weight is
7 g) with an electron beam having routine parameters
(40 MeV; 0.3 mA), one can provide the 47Sc capacity of
up to 1 GBq/h at a low content of by-products. Applica-
tion of a more powerful machine [13] enables to in-
crease the capacity of the technology by up to an order
of values. The 47Sc specific activity, obtained with due
regard to the profile of the X-ray flux, appears much
higher (up to by order of values) than the estimates re-
sulting from activation of the small experimental targets
[2]. At the same time, the experimentally determined
yield of the scandium by-products in natural titanium
turned out lower by orders of values than that obtained
elsewhere by simulation [4].
The comparative characteristics of various methods
of the 47Sc production are listed in Table 2.
Table 2
Comparative characteristics of 47Sc production methods
Reaction Beam
characteristics
Target
characteristics
Sc-47 yield,
GBq/day
By-
products
Rel. yield,
% Ref.
47Ti(n,p)47Sc En>1 MeV
Фn=5.81014, ncm-2s-1
47TiO2; 10 g 1103
46Sc
48Sc
3.810-3
6.210-2
[14]
47Ti(n,p)47Sc En>1 MeV
Фn=11013, ncm-2s-1
47Ti; 10 g up to 10 46Sc 510-2 [1]
46Ca(n,)47Ca47Sc En=0.025 eV
Фn=11013, ncm-2s-1
46Ca; 10 g up to 1102 46Sc <510-3 [1]
48Ti(p,2p)47Sc Ep=35 MeV
Ip=50 A
natTi; 17.4 mm 2.5
44mSc
46Sc
48Sc
90
5
4
[14]
48Ca(p,2n)47Sc Ep=24…17 MeV
Ip=1 A
natCaCO3; 0.35, gcm-2 3.510-3
46Sc
48Sc
0.2
14.7 [15]
48Ti(,p)47Sc Ee=40 MeV
Ie=300 A
natTi; 7 g 18
46Sc
48Sc
0.87
9.2 -
energy (keV)
energy (keV)
ISSN 1562-6016. ВАНТ. 2020. №3(127) 162
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Article received 18.01.2020
ОЦЕНКА ФОТОЯДЕРНОГО ВЫХОДА 47Sc В ТЕХНОЛОГИЧЕСКОЙ МИШЕНИ
Н.П. Дикий, Ю.В. Ляшко, В.А. Шевченко, А.Э. Тенишев, В.Л. Уваров, А.А. Захарченко
47Sc считается перспективным бета-эмиттером в иммунотерапии рака. Для производства изотопа без но-
сителя может быть использована реакция 48Ti(,p)47Sc в поле тормозного излучения ускорителя электронов.
На основе разработанной аналитической модели и метода совместной активации двух фольг установлены
основные характеристики фотоядерного производства изотопов и оптимальные размеры технологической
мишени. Полученные экспериментальные данные по выходу 47Sc и основных примесных изотопов скандия в
тонких фольгах из природного титана в диапазоне значений энергии электронов 35…95 МэВ позволяют
уточнить имеющиеся данные по сечению реакции 48Ti(,p)47Sc. На основе этих результатов методом моде-
лирования рассчитаны общая и удельная активность 47Sc в цилиндрических мишенях из титана оптималь-
ных размеров. Проведено сравнение производительности фотоядерной технологии производства 47Sc с дру-
гими методами.
ОЦІНКА ФОТОЯДЕРНОГО ВИХОДУ 47Sc У ТЕХНОЛОГІЧНІЙ МІШЕНІ
М.П. Дикий, Ю.В. Ляшко, В.А. Шевченко, А.Е. Тєнішев, В.Л. Уваров, О.О. Захарченко
47Sc вважається перспективним бета-емітером в імунотерапії раку. Для виробництва ізотопу без носія
може бути використана реакція 48Ti(,p)47Sc у полі гальмівного випромінення прискорювача електронів. На
основі розробленої аналітичної моделі і методу сумісної активації двох фольг встановлені основні характе-
ристики фотоядерного виробництва ізотопів та оптимальні розміри технологічної мішені. Одержані експе-
риментальні дані щодо виходу 47Sc і основних домішкових ізотопів скандію в тонких фольгах з природного
титану в діапазоні значень енергії електронів 35…95 МеВ дозволяють уточнити наявні дані щодо перетину
реакції 48Ti(,p)47Sc. На основі цих результатів методом моделювання розраховані загальна і питома актив-
ність 47Sc у циліндричних мішенях з титану оптимального розміру. Проведено порівняння продуктивності
фотоядерної технології виробництва 47Sc з іншими методами.
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