arXiv subjects

I. S. Timchenko

Publications and source records attributed to I. S. Timchenko.

At least 19 recordsLinked to original sources

arXiv2025

Cross-section of the ${^{\rm nat}\rm{Ni}}(\gamma,{\rm p} x\rm n)^{58}\rm{Co}$ reaction at the bremsstrahlung end-point energy of 35-94 MeV

The photoproduction of the $^{58}\rm{Co}$ nuclei on ${^{\rm nat}\rm{Ni}}$ was studied using the induced $\gamma$-activity method and off-line $\gamma$-ray spectrometric technique. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT, Ukraine. The total flux-averaged cross-section $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ for the ${^{\rm nat}\rm{Ni}}(\gamma,{\rm p} x\rm n)^{58}\rm{Co}$ reaction has been measured in the range of bremsstrahlung end-point energies $E_{\rm{\gamma max}}$ = 35-94 MeV. The obtained $\langle{\sigma(E_{\rm{\gamma max}})}\rangle$ were compared with theoretical estimates. The theoretical values of $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm th}$ were calculated using the partial cross-sections $\sigma(E)$ from the TALYS1.96 code for different level density models and gamma strength functions.

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arXiv2025

Facility based on electron linac LUE-40 -- current state and main research directions

The paper describes the state of the installation based on the linear accelerator LUE-40 after restoration in 2023. Additional devices have been developed and created to conduct nuclear physics research. The main beam parameters are given. The electron energy range has been expanded and is currently 16-95 MeV with an average beam current of up to 6 $\mu$A. The main areas of scientific research are described and the results are presented.

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arXiv2024

Cross-sections of photoneutron reaction $^{\rm nat}$Mo($\gamma,x$n)$^{\rm 93m}$Mo at the bremsstrahlung energy up to 95 MeV

The photoproduction of the $^{\rm 93m}$Mo nucleus on natural molybdenum was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using the activation method and off-line $\gamma$-ray spectrometric technique. For the $^{\rm nat}$Mo($\gamma,x$n)$^{\rm 93m}$Mo reaction the experimental flux-averaged cross-section <$\sigma(E_{\rm \gamma max})$>$_\rm m$ at the bremsstrahlung end-point energy range of 38--93 MeV was first time determined. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm \gamma max})$ and flux-averaged cross-sections <$\sigma(E_{\rm \gamma max})$>$_{\rm m,g}$ for the $^{\rm nat}$Mo($\gamma,x$n)$^{\rm 93m,g}$Mo reactions were calculated using the cross-sections $\sigma(E_{\rm \gamma})$ from the TALYS1.96 code for different gamma strength functions and level density models. The comparison showed strong discrepancies between the experimental values and the theoretical results of <$\sigma(E_{\rm \gamma max})$>$_m$.

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arXiv2023

Study the isomeric ratios in photonuclear experiments on the LUE-40 linac RDC "Accelerator" NSC KIPT

The results of the photoproduction of isomeric pairs from the (γ,xn) and (γ,pxn) reactions on nuclei from Zr up to Ta at the bremsstrahlung end-point energy range 30-100 MeV are systematized. Measurements were performed at the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT using the activation method and off-line γ-ray spectrometric technique. The theoretical isomeric ratios IR for the nuclei-products of studied reactions were calculated using the cross-sections σ(E) from the TALYS1.95 code for six different level density models. The data from the international databases were additionally used to compare experimental results and theoretical predictions. The obtained results let us make conclusions about trends of values and energy dependence of IR in studied photonuclear reactions. Further directions of experimental research in the RDC "Accelerator" NSC KIPT are discussed.

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arXiv2023

Cross-section of the ${^{95\rm}\rm{Nb}}$ production on natural molybdenum at the bremsstrahlung end-point energy up to 95 MeV

The photoproduction of $^{95\rm m}$Nb on ${^{\rm nat}\rm{Mo}}$ was studied using the electron beam of the LUE-40 linac RDC "Accelerator" NSC KIPT. Measurements were performed using activation and off-line $γ$-ray spectrometric techniques. The experimental flux-averaged cross-section $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m}}$ for the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m}$Nb reaction at the bremsstrahlung end-point energy range of 38--93 MeV has been first time obtained. The estimated values $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{g}}$ for the formation of $^{95}$Nb in the ground state and total cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{tot}}$ for the studied reaction were determined. The theoretical values of the yields $Y_{\rm m,g,tot}(E_{\rm{γmax}})$ and flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m,g,tot}}$ for the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m,g,tot}$Nb reactions were calculated using the cross-sections $σ(E)$ from the TALYS1.95 code for six different level density models. The comparison showed a significant excess of the experimental results over the theoretical $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m,g,tot}}$ values.

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arXiv2023

Production of ${^{180\rm{m}}}$Hf in photoproton reaction ${^{181}}$Ta$(γ,p)$ at energy $E_{\rm{γmax}}$ = 35-95 MeV

The production of the $^{180\rm{m}}\rm{Hf}$ nuclei in the photoproton reaction ${^{181}\rm{Ta}}(γ,p)$ was studied at end-point bremsstrahlung energies $E_{\rm{γmax}}$ = 35-95 MeV. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT with the use of the $γ$ activation and off-line $γ$-ray spectroscopy. The experimental values of the bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m}}$ for the ${^{181}\rm{Ta}}(γ,p)^{180\rm{m}}\rm{Hf}$ reaction were determined, and at $E_{\rm{γmax}} > 55$ MeV obtained for the first time. The measured values, also as the literature data, are significantly exceed the theoretical flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$. The $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ values were calculated using the cross-section $σ(E)$ computed with the TALYS1.95 code for six different level density models. A comparative analysis of the calculated total cross-sections for the reactions ${^{181}\rm{Ta}}(γ,p)^{180}\rm{Hf}$ and ${^{181}\rm{Ta}}(γ,n)^{180}\rm{Ta}$ was performed. It was shown that the photoproton $(γ,p)$ to photoneutron $(γ,n)$ strength ratio is consistent with the estimates based on the isospin selection rules and the value from the $(e,e'p)$ experiment.

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arXiv2023

Isomeric pair ${^{95\rm m,g}\rm{Nb}}$ in photonuclear reactions on $^{\rm nat}$Mo at end-point bremsstrahlung energy of 35-95 MeV

The ${^{\rm nat}\rm{Mo}}(γ,x\rm np)^{95\rm m,g}$Nb photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. Experiment was performed using the activation and off-line $γ$-ray spectrometric technique. The experimental isomeric yield ratio $d(E_{\rm{γmax}}) = Y_{\rm m}(E_{\rm{γmax}}) / Y_{\rm g}(E_{\rm{γmax}})$ was determined for the reaction products $^{95\rm m,g}\rm{Nb}$ at the end-point bremsstrahlung energy $E_{\rm{γmax}}$ range of 35-95 MeV. The obtained values of $d(E_{\rm{γmax}})$ are in satisfactory agreement with the results of other authors and extend the range of previously known data. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm{γmax}})$ and the isomeric yield ratio $d(E_{\rm{γmax}})$ for the isomeric pair $^{95\rm m,g}\rm{Nb}$ from the ${^{\rm nat}\rm{Mo}}(γ,x\rm np)$ reaction were calculated using the partial cross-sections $σ(E)$ from the TALYS1.95 code for six different level density models $LD$. The comparison showed a noticeable excess (more than 3.85 times) of the experimental isomeric yield ratio over all theoretical estimates. At the investigated range of $E_{\rm{γmax}}$ the theoretical dependence of $d(E_{\rm{γmax}})$ on energy was confirmed - the isomeric yield ratio smoothly decreases with increasing energy.

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arXiv2022

Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups

In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT, the flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{exp}}$ of photonuclear reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ were measured using the $γ$-activation technique. The theoretical flux-average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ were computed using the partial cross-section $σ(E)$ values from the TALYS1.9-1.95 codes and bremsstrahlung $γ$-flux calculated using GEANT4.9.2. Two different experimental setups were used in the experiments: an aluminum electron absorber and a deflecting magnet to clean the bremsstrahlung $γ$-flux from electrons. A comparison of the flux-average cross-sections measured for two experimental setups was performed. The possibility of using the reactions ${^{100}\rm{Mo}}(γ,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(γ,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(γ,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(γ,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(γ,n)^{180g}\rm{Ta}$ as monitors of the bremsstrahlung $γ$-flux for the energy range 30-100 MeV was investigated.

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arXiv2022

Photonuclear reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$ and ${^{63}\rm{Cu}}(γ,xn)^{63-x}\rm{Cu}$ cross-sections in the energy range $E_{\rm{γmax}}$ = 35-94 MeV

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ for the photonuclear reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,n)^{62}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,2n)^{61}\rm{Cu}$ and ${^{63}\rm{Cu}}(γ,3n)^{60}\rm{Cu}$ have been measured in the range of bremsstrahlung end-point energies $E_{\rm{γmax}}$ = 35-94 MeV. The experiments were performed with the electron beam from the NSC KIPT linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of the flux-average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{th}}$ was carried out using the cross-section $σ(E)$ values from the TALYS1.95 code with the default options. It is shown that the experimental average cross-sections for the reactions ${^{65}\rm{Cu}}(γ,n)^{64}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,n)^{62}\rm{Cu}$, ${^{63}\rm{Cu}}(γ,2n)^{61}\rm{Cu}$ are systematically higher than the theoretical estimates in the TALYS1.95 code. The obtained $\langle{σ(E_{\rm{γmax}})}\rangle$ supplement the data of different laboratories for the case of reactions $(γ,n)$ and $(γ,2n)$. For the reaction ${^{63}\rm{Cu}}(γ,3n)^{60}\rm{Cu}$, the values of $\langle{σ(E_{\rm{γmax}})}\rangle$ were measured for the first time.

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arXiv2022

Magnetic system for cleaning the gamma beam at the LUE-40 electron linac output

The bremsstrahlung of accelerated electrons passing through a converter is used to study multiparticle photo-nuclear reactions. The results of calculations, numerical modeling, design, and testing of a special magnetic cleaning system to obtain a "pure" beam of bremsstrahlung quanta when studying the cross-sections of such reactions at the LUE-40 linac are presented. The system is based on commercially available permanent magnets of rectangular cross-sections. The maximum on-axis field is 0.9 T, which provides sufficient separation of the electron beam and gamma rays at a distance of more than 90 mm from the magnet.

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arXiv2022

Photonuclear reactions $^{nat}$Ni($γ$,xn)$^{57}$Ni and $^{nat}$Ni($γ$,xn)$^{56}$Ni in the energy range E$_{γmax}$ = 35...94 MeV

The total bremsstrahlung flux-averaged cross-sections <$σ$(E$_{γmax}$)> for the photonuclear reactions $^{nat}$Ni($γ$,xn)$^{57}$Ni and $^{nat}$Ni($γ$,xn)$^{56}$Ni have been measured in the range of end-point energies E$_{γmax}$ = 35...94 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of the flux-average cross-sections <$σ$(E$_{γmax}$)>$_{th}$ was carried out using the partial cross-section values $σ$(E) computed with the TALYS1.95 code and bremsstrahlung $γ$-flux calculated by GEANT4.9.2. The experimental results are compared with theoretical calculations and data from the literature. The obtained <$σ$(E$_{γmax}$)> values expand the energy range of previously known experimental data.

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arXiv2021

Cross-sections of photoneutron reactions on $^{181}$Ta at $e_{\rm γmax}$ up to 95 MeV

The total bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ for the photonuclear reactions $^{181}\rm{Ta}(γ,\textit{x}n; \textit{x} \leq 8)^{181-\textit{x}}\rm{Ta}$ have been measured in the range of end-point energies $E_{\rm γmax}$ up to 95 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the activation and off-line $γ$-ray spectrometric technique. The calculation of average cross-sections was carried out using the cross-section values computed with the TALYS1.95 code for different level density models $LD$ 1-6. A comparison between the experimental total cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and the theoretical values has shown satisfactory agreement for the $^{181}\rm{Ta}(γ,\textit{x}n)$ reactions with the escape of 1-4, 6 and 7 neutrons. The closest agreement with the measured data is observed with the $LD$5 computation version, which represents the microscopic level density model taking into account Hilaire's combinatorial tables.

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arXiv2021

Isomeric Ratio of the $^{181}\rm{Ta}(γ,3n)^{178m,g}\rm{Ta}$ Reaction Products at Energy $E_{\rm{γmax}}$ up to 95 MeV

The photoneutron reaction $^{181}\rm{Ta}(γ,3n)^{178m,g}\rm{Ta}$ was investigated with the beam from the NSC KIPT electron linear accelerator LUE-40. The measurements were performed using the residual $γ$-activity method. The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$, $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{m}}$, $\langle{σ(E_{\rm{γmax}})}\rangle_{\rm{g}}$ and the isomeric ratio of the reaction products $d(E_{\rm{γmax}})$ have been measured. Theoretical values of averaged cross-sections and isomeric ratio were calculated using partial cross-sections from the TALYS1.95 code for different level density models $LD$ 1-6. The obtained experimental $d(E_{\rm{γmax}})$ agree with the literature data, but differ from the theoretical values in absolute magnitude and the behavior of the energy dependence. A comparison of the found averaged cross-sections with the calculated ones showed the best agreement for the case of the $LD$ 5 model.

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arXiv2021

Cross-sections of photonuclear reactions on $^{nat}$Mo targets at end-point bremsstrahlung energy up to $E_{γmax}$ = 100 MeV

Experiments to determine the yields and bremsstrahlung flux-averaged cross-sections <$σ(E_{γmax})$> of photonuclear reactions on the natural Mo targets were performed on the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $γ$-activation technique. The bremsstrahlung end-point energies were in the range $E_{γmax}$ = 35...80 MeV. The bremsstrahlung quantum flux was calculated with the program GEANT4.9.2 and, in addition, was monitored using the $^{100}$Mo$(γ,n)^{99}$Mo reaction. Calculations of the yields and average cross-sections <$σ(E_{γmax})$> for photonuclear reactions on stable Mo isotopes were computed using the $σ(E)$ cross-sections from the TALYS1.95 code (for the level density model LD1). A comparison of experimental and calculated cross-sections <$σ(E_{γmax})$> for reactions $^{92}$Mo$(γ,2n)^{90}$Mo and $^{92}$Mo$(γ,pn)^{90}$Nb was performed.

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arXiv2021

Cross-sections for the ${^{27}\!\rm{al}}(γ,\textit{x})^{22}\rm{na}$ multichannel reaction with the 28.3 mev difference of the reaction thresholds

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and the cross-sections per equivalent photon $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ were first measured for the photonuclear multichannel reaction ${^{27}\!\rm{Al}}(γ,\textit{x})^{22}\rm{Na}$ at end-point bremsstrahlung gamma energies ranging from 35 MeV to 95 MeV. The experiments were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $γ$-activation technique. The bremsstrahlung quantum flux was calculated with the program GEANT4.9.2 and, in addition, was monitored by means of the $^{100}\rm{Mo}(γ,n)^{99}\rm{Mo}$ reaction. The flux-averaged cross-sections were calculated using the partial cross-section $σ(E)$ values computed with the TALYS1.95 code for different level density models. Consideration is given to special features of calculating the cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ for the case of the final nucleus $^{22}\rm{Na}$ production in the $^{27}\!\rm{Al}$ photodisintegration reaction via several partial channels $\textit{x}$: $\rm{n}α+ dt + npt + 2n{^{3}\rm{He}} + n2d + 2npd + 2p3n$.

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arXiv2021

Photoneutron Reactions $^{181}\rm{Ta}(γ,\textit{x}n; \textit{x} = 1 ÷8)^{181-\textit{x}}\rm{Ta}$ AT $E_{\rm{γmax}}$ = 80 $÷$ 95 MeV

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ for the $^{181}\rm{Ta}(γ,\textit{x}n; \textit{x} = 1 ÷8)^{181-\textit{x}}\rm{Ta}$ photoneutron reactions have been measured at end-point bremsstrahlung energies ranging from 80 MeV to 95 MeV. The measurements were performed with the beam from the NSC KIPT electron linear accelerator LUE-40 using the residual $γ$-activity method. The theoretical $\langle{σ(E_{\rm{γmax}})}\rangle$ values were computed using the cross-sections $σ(E)$ from TALYS1.9 code. A comparison between the measured cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and the theoretical values has demostrated their good agreement for the reactions with escape of up to 6 neutrons, and substantial differences for the $(γ,7\rm{n})$ and $(γ,8\rm{n})$ reactions. Isomeric ratios of the average cross-sections $d(E_{\rm{γmax}})$ have been found for the $^{181}\rm{Ta}(γ,3n)^{178g,m}\rm{Ta}$ reaction products. The results have been compared with the literature data and the computations based on TALYS1.9 code.

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arXiv2021

Photoneutron reactions on $^{\text{93}}$Nb at $E_{γ\text{max}}$=33-93 MeV

The bremsstrahlung flux-averaged cross sections for the photoneutron reactions $^{\text{93}}$Nb($γ$,xn;x=1-5)$^{\text{(93-x)m,g}}$Nb were measured in the range of boundary energies of bremsstrahlung $γ$-quanta $E_{γ\text{max}}$=33-93 MeV with a step $ΔE_{γ\text{max}}\approx $ 2 MeV. The isomeric ratios of the average cross-sections of the products of the reactions $^{\text{93}}$Nb ($γ$ ,4n)$^{\text{89m,g}}$Nb and $^{\text{93}}$Nb($γ$,5n)$^{\text{88m,g}}$ Nb were determined in the energy ranges $E_{γ\text{max}}$ = 50-93 and 70-93 MeV, respectively. The experiments were carried out on the beam of the linear electron accelerator LU-40 of the Science and Research Establishment (SRE) "Accelerator" at National Science Center Kharkov Institute of Physics and Technology (NSC KIPT) using the method of induced activity. Calculations of the cross sections, average cross sections, and isomeric ratios of the reaction products were performed using the TALYS 1.9 code with default parameters and the GEANT4 code. The tendency of a more successful description of the average cross sections of photoneutron reactions with the formation of final odd-even Nb nuclei than odd-odd Nb nuclei is revealed. The experimental average cross sections for the reactions ($γ$,2n) and ($γ$,4n) are in good agreement with theory, while in the case of reactions ($γ$,n), ($γ$,3n), and ($ γ$,5n), some discrepancies are observed. The results obtained for the reactions ($γ$,n), ($γ$,3n) and ($γ$,4n) are in satisfactory agreement with the known literature data. The average cross sections for the reactions ($γ$,2n) and ($γ$,5n) and the isomeric ratios of the reaction products $^{\text{93}}$Nb($γ$,5n)$^{\text{88m,g}}$Nb were measured for the first time.

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arXiv2020

Cross-sections for the ${^{27}\!\rm{Al}}(γ,\textit{x})^{24}\rm{Na}$ multiparticle reaction at $E_{\rm{γmax}}$ = 40 $÷$ 95 MeV

The bremsstrahlung flux-averaged cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and the cross-sections per equivalent photon $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ were measured for the photonuclear multiparticle reaction $^{27}\!\rm{Al}(γ,\textit{x}; \textit{x} = {^{3}\rm{He}} + pd + 2pn)^{24}\rm{Na}$ at bremsstrahlung end-point energies ranging from 40 MeV to 95 MeV. The experiments were performed using the beam from the NSC KIPT electron linear accelerator LUE-40 with the use of the $γ$-activation technique. The bremsstrahlung quantum flux was calculated with the program GEANT4 and, in addition, was monitored by means of the $^{100}\rm{Mo}(γ,n)^{99}\rm{Mo}$ reaction. The cross-sections $σ(E)$ were computed using the TALYS1.9 code with the default options. The measured average cross-sections $\langle{σ(E_{\rm{γmax}})}\rangle$ and $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ have appeared to be higher by factors of 2.0 to 2.4 than the theoretical results. The experimental results have been found to be in good agreement with the data of other laboratories. Consideration is given to special features of calculation of $\langle{σ(E_{\rm{γmax}})}\rangle$ and $\langle{σ(E_{\rm{γmax}})_{\rm{Q}}}\rangle$ for the $^{27}\!\rm{Al}(γ,\textit{x})^{24}\rm{Na}$ reaction, with occurrence of three $^{27}\!\rm{Al}$ photodisintegration channels. The paper also discusses the possibility of using the $^{27}\!\rm{Al}(γ,\textit{x})^{24}\rm{Na}$ reaction for monitoring the bremsstrahlung $γ$-quantum flux in the photon energy region above 30 MeV.

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