4 research outputs found
Isomer ratios and mean angular momenta of photonuclear reaction products
Isomer ratios and mean angular momenta are obtained both for photofission products of
237Np, 238U and for nuclei
122,120m,gSb and 117m,gIn. Photonuclear reactions
121Sb(Ξ³,n)120m,gSb, 123Sb(Ξ³,n)122m,gSb, 118Sn(Ξ³,p)117m,gIn were studied in
the last cases. The technique of gamma-ray spectrometry for isomeric ratio determination was used. Target nuclei
were irradiated by bremsstrahlung spectrum of microtron M-30. Comparison of isomer ratios calculated by Empire II
code with experimental data was performed. Effects of the nuclear structure model parameters on values of isomer
ratios are discussedΠΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ ΡΠ·ΠΎΠΌΠ΅ΡΠ½Ρ Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Π½Ρ ΡΠ° Π²ΠΈΠ·Π½Π°ΡΠ΅Π½ΠΎ ΡΠ΅ΡΠ΅Π΄Π½Ρ ΠΊΡΡΠΎΠ²Ρ ΠΌΠΎΠΌΠ΅Π½ΡΠΈ Π΄Π»Ρ ΠΏΡΠΎΠ΄ΡΠΊΡΡΠ² ΡΠΎΡΠΎΠ΄ΡΠ»Π΅Π½Π½Ρ ΡΠ΄Π΅Ρ 238U Ρ 237Np, Π° ΡΠ°ΠΊΠΎΠΆ Π²ΠΈΠΌΡΡΡΠ½Ρ ΡΠ·ΠΎΠΌΠ΅ΡΠ½Ρ Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Π½Ρ Π΄Π»Ρ ΡΠ΄Π΅Ρ 120,122m,gSb ΠΈ 117m,gIn Π² ΡΠ΅Π°ΠΊΡΡΡΡ
(Ξ³,n) ΡΠ° (Ξ³,p). ΠΠΏΡΠΎΠΌΡΠ½Π΅Π½Π½Ρ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΎΡΡ Π³Π°Π»ΡΠΌΡΠ²Π½ΠΈΠΌΠΈ Ξ³-ΠΊΠ²Π°Π½ΡΠ°ΠΌΠΈ ΠΌΡΠΊΡΠΎΡΡΠΎΠ½Ρ Π-30 Π· ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΡ Π΅Π½Π΅ΡΠ³ΡΡΡ ΡΠΏΠ΅ΠΊΡΡΡ 16 ΡΠ° 15 ΠΠ΅Π. ΠΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ Π·Π°Π»Π΅ΠΆΠ½ΠΎΡΡΡ ΡΠ·ΠΎΠΌΠ΅ΡΠ½ΠΈΡ
Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Ρ Π²ΡΠ΄ ΠΊΡΡΠΎΠ²ΠΈΡ
ΠΌΠΎΠΌΠ΅Π½ΡΡΠ² Π·Π±ΡΠ΄ΠΆΠ΅Π½ΠΈΡ
ΡΠ΄Π΅Ρ Π· Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½ΡΠΌ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΈ Empire II Π΄Π»Ρ ΡΠΎΠ·ΡΠ°Ρ
ΡΠ½ΠΊΡ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ ΡΠ΄Π΅ΡΠ½ΠΈΡ
ΡΠ΅Π°ΠΊΡΡΠΉ.ΠΠ·ΠΌΠ΅ΡΠ΅Π½Ρ ΠΈΠ·ΠΎΠΌΠ΅ΡΠ½ΡΠ΅ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΈ ΠΈΠ·Π²Π»Π΅ΡΠ΅Π½Ρ ΡΡΠ΅Π΄Π½ΠΈΠ΅ ΡΠ³Π»ΠΎΠ²ΡΠ΅ ΠΌΠΎΠΌΠ΅Π½ΡΡ Π΄Π»Ρ ΠΏΡΠΎΠ΄ΡΠΊΡΠΎΠ² ΡΠΎΡΠΎΠ΄Π΅Π»Π΅Π½ΠΈΡ ΡΠ΄Π΅Ρ 238U ΠΈ 237Np, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΈΠ·ΠΌΠ΅ΡΠ΅Π½Ρ ΠΈΠ·ΠΎΠΌΠ΅ΡΠ½ΡΠ΅ ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ Π΄Π»Ρ ΡΠ΄Π΅Ρ 120,122m,gSb ΠΈ 117m,gIn Π² ΡΠ΅Π°ΠΊΡΠΈΡΡ
(Ξ³,n) ΠΈ (Ξ³,p). ΠΠ±Π»ΡΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΎΡΡ ΡΠΎΡΠΌΠΎΠ·Π½ΡΠΌΠΈ Ξ³-ΠΊΠ²Π°Π½ΡΠ°ΠΌΠΈ ΠΌΠΈΠΊΡΠΎΡΡΠΎΠ½Π° Π-30 Ρ ΠΌΠ°ΠΊΡΠΈΠΌΠ°Π»ΡΠ½ΠΎΠΉ ΡΠ½Π΅ΡΠ³ΠΈΠ΅ΠΉ ΡΠΏΠ΅ΠΊΡΡΠ° 16 ΠΈ 15 ΠΡΠ. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Ρ Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΈΠ·ΠΎΠΌΠ΅ΡΠ½ΡΡ
ΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΠΉ ΠΎΡ ΡΠ³Π»ΠΎΠ²ΡΡ
ΠΌΠΎΠΌΠ΅Π½ΡΠΎΠ² Π²ΠΎΠ·Π±ΡΠΆΠ΄Π΅Π½Π½ΡΡ
ΡΠ΄Π΅Ρ Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΡ Empire II Π΄Π»Ρ ΡΠ°ΡΡΠ΅ΡΠ° Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊ ΡΠ΄Π΅ΡΠ½ΡΡ
ΡΠ΅Π°ΠΊΡΠΈΠΉ
The use of selected monochromatic X-rays to induce a cascade of gamma transitions from the 31-year nuclear isomer to the 4 second isomeric state of Hf-178
The Hf-178m2 nuclear spin isomer stores 2.45 MeV of
energy for a half life of 31 years. Unperturbed, such nuclei radiate away
the stored energy through the emission of gamma photons from electromagnetic
(EM) transitions occurring within the nuclei. It has been shown that the
irradiation of samples containing such nuclei with pulsed X-rays can
accelerate the rate of the EM transitions by relaxing the selection rules
upon changes of angular momenta. To date, most work has been done with
incident X-ray energies between 9 and 10 keV, and in such cases the
acceleration of the rate of gamma emission is immediate. Reported here is a
channel for deexcitation excited by more energetic X-rays that results in a
cascade of gamma transitions that includes a 4 second statistical time lag.
This more protracted release of the energy stored in samples of the Hf-178m2
nuclear isomers encourages consideration of potential mechanical and thermal
applications
Gamma-ray transitions induced in nuclear spin isomers by X-rays
Because of the high density of energy storage and the large cross section for its release there is considerable significance of the triggering of induced gamma emission from nuclear spin isomers to efforts to develop intense sources of short-wavelength radiation. The work reported here describes the current experimental focus and results recently obtained