The splitting of the transition from a discrete to an autoionization state, used in a three-step photoionization scheme of lutetium 5d6s2 2D3/2–5d6s6p ^4F_5/2^^∘ –5d6s7s 4D3/2–(53375 cm–1) _1/2^^∘ has been studied. The splitting is proportional to the square root of the intensity, which corresponds to the Autler–Townes effect.

Acceleration of laser-induced plasma created as a result of three-step photoionization of atomic vapor by pulsed radiation of dye lasers pumped by copper-vapor lasers is studied experimentally. The acceleration was achieved due to the alternating magnetic field appearing upon propagation of a current pulse through an inductor located in direct proximity from the area of laser protoionization of atomic lutetium vapor.

The photoionization spectrum in the second step of the three-step lutetium photoionization scheme 5 d 6 s 2 2 D 3/2 – 5 d 6 s 6 p 4 F_5/2^o – 5 d 6 s 7 s 4 D 3/2 – (53 375 cm –1 )_1/2^o has been measured. The effect of two-photon transitions has been studied experimentally compared to one-photon transitions.

We present results on isotopically selective lutetium photoionization using dye lasers pumped by copper vapor lasers as applied to the problem of obtaining the Lu-177 radionuclide for medical applications.

The selectivity and efficiency of laser photoionization of the 177mLu nuclear isomer by a three-stage photoionization scheme of lutetium 5d6s2 2D3/2−5d6s6p4F05/2−5d6s7s4D3/2−(53375 cm–1)01/2 were studied for the first time using pulsed tunable narrow-band dye systems pumped by copper vapor lasers. The study was carried out in relation to the problem of developing a hospital-based autonomous generator of the 177Lu radionuclide.

The splitting of the first and second transitions in the lutetium photoionisation scheme is studied in a wide range of laser radiation intensities, and the Rabi frequencies as functions of the radiation intensity are determined. Based on the results, we have obtained the decay branching coefficients of 0.54 and 0.41 for the first and second transitions, respectively.

The effect of laser radiation polarization on the photoionization of lutetium is studied using three-stage scheme 5d6s 2 2 D 3/2 -5d6s6p 4 F o 5/2 -5d6s7s 4 D 3/2 - (53375 cm -1 ) o 1/2 . It is shown that in a number of cases, there is a limitation of photoionization associated with the features of coherent photoexcitation. Keywords: laser selective photoionization, lutetium-177.

The effect of laser radiation polarization on the photoionization of lutetium is studied using three-stage scheme 5d6s2 2D3/2−5d6s6p 4Fo5/2−5d6s7s 4D3/2−(53375 cm−1)o1/2. It is shown that in a number of cases, there is a limitation of photoionization associated with the features of coherent photoexcitation.

Принимая во внимание недостатки электростатической системы экстракции фотоионов, применяемой в настоящее время в системах лазерного разделения изотопов, рассмотрены альтернативные возможности. Наиболее перспективной представляется система экстракции с использованием J × B дрейфа плазменного сгустка как целое без разделения зарядов. Экспериментально получено нарастание импульсного тока в электроде индукторе до 1,5 кА за 10 мкс, что соответствует значению поперечной горизонтальной составляющей индукции магнитного поля в рабочем объеме системы лазерного разделения изотопов 11 мТл при скорости нарастания горизонтальной составляющей 4000 Тл/с. Это означает, что на основе современной элементной базы с применением полупроводниковых приборов с повышенными коммутационными и частотными характеристиками, возможно создание необходимых магнитных полей для осуществления экстракции фотоионов на основе J × B дрейфа. Taking into account the disadvantages of the electrostatic system for the extraction of photoions currently used in laser isotope separation systems, alternative possibilities are considered. The most promising is the extraction system using the J × B drift of the plasma bunch as a whole without charge separation. An increase in the pulsed current in the electrode inductor to 1,5 kA in 10 μs was experimentally obtained, which corresponds to the value of the transverse horizontal component of the magnetic field induction in the operation volume of the laser isotope separation system of 11 mT at the rate of rise of the horizontal component of 4000 T/s. This means that, on the basis of a modern element base with the use of semiconductor devices with increased switching and frequency characteristics, it is possible to create the necessary magnetic fields for the extraction of photoions based on the J × B drift.

The selectivity of laser photoionisation of 177m Lu nuclear isomer with respect to natural isotopes has been studied for the first time using a three-stage lutetium photoionisation scheme .

Development of the laser photoionization method for obtaining 177Lu radionuclide for a medical purpose requires the knowledge of the light-saturation intensities at each stage of the Lu photoionization scheme (5d6s22D3/2−5d6s6p4F$$_{{5/2}}^{^\circ }$$−5d6s7s4D3/2−(53 375 cm–1)$$_{{1/2}}^{^\circ }$$), taking into account the used components of the hyperfine structure of transitions. The effective excitation cross sections of various hyperfine transition components for 175Lu, 176Lu, 177Lu, and 177mLu isotopes have been experimentally determined for radiations of pulsed tunable dye lasers pumped by copper-vapor lasers.

The hyperfine structure of transitions of the three-step photoionization scheme of lutetium, 5d6s2 2D3/2−5d6s6p 4F$$_{{5/2}}^{^\circ }$$−5d6s7s 4D3/2−(53 375 cm–1)$$_{{1/2}}^{^\circ }$$, for 177mLu nuclear isomer has been investigated for the first time by laser resonance photoionization mass spectroscopy. Hyperfine-splitting constants, energy levels, and magnetic dipole and electrical quadrupole moments of the 177mLu nucleus are determined. Isotope shifts of the isomer spectral lines relative to natural isotopes and 177Lu have been investigated.

Разработка лазерного фотоионизационного метода получения радионуклида 177Lu для применения в медицине требует знания интенсивностей светового насыщения по каждой ступени схемы фотоионизации лютеция (5d6s2 2D3/2-5d6s6p 4Fo5/2-5d6s7s 4D3/2-(53375 сm-1)o1/2) с учетом используемых компонент сверхтонкой структуры переходов. В работе экспериментально определены эффективные сечения возбуждения различных сверхтонких компонент переходов для изотопов 175Lu, 176Lu, 177Lu и 177mLu излучением импульсных перестраиваемых по длине волны лазеров на красителях, накачиваемых лазерами на парах меди. Ключевые слова: лазерная фотоионизация, сверхтонкая структура, 177Lu, лазерное разделение изотопов.

Впервые методом лазерной резонансной фотоионизационной спектроскопии исследована сверхтонкая структура переходов трехступенчатой схемы фотоионизации лютеция 5d6s2 2D3/2--5d6s6p4Fo5/2-- 5d6s7s4D3/2--(53375 cm-1)o1/2 для ядерного изомера 177mLu. В результате определены константы сверхтонкого расщепления и энергии уровней, а также магнитный дипольный и электрический квадрупольный моменты ядра 177mLu. Исследованы изотопические сдвиги спектральных линий изомера по отношению к природным изотопам и 177Lu. Ключевые слова: изотопический сдвиг, сверхтонкая структура, квадрупольный момент.

AbstractThe hyperfine structure of transitions in the three-step scheme 5 d 6 s ^22 D _3/2–5 d 6 s 6 p ^4 F $$_{{5/2}}^{^\circ }$$ –5 d 6 s 7 s ^4 D _3/2– (53 375 cm^–1) $$_{{1/2}}^{^\circ }$$ of lutetium ionization is studied for ^175Lu, ^176Lu, and ^177Lu isotopes using the photoionization laser spectroscopy method. Values of the magnetic dipole ( A ) and electric quadrupole ( B ) interaction constants are determined, as well as the energies, the isotope shifts, and the radiative lifetimes for the 5 d 6 s 7 s ^4 D _3/2 and (53 375 cm^–1) $$_{{1/2}}^{^\circ }$$ levels.

Abstract We consider the selectivity obtained by laser photoionisation of the 177Lu radioisotope according to the three-stage scheme from the viewpoint of the task of isolating the radionuclide for medical use. The selectivity attained through various photoionisation channels and the impact of multiphoton processes and the laser radiation spectrum on the photoionisation selectivity are investigated.

The hyperfine structure of transitions in the three-step scheme 5d6s22D3/2–5d6s6p4F\(_{{5/2}}^{^\circ }\)–5d6s7s4D3/2– (53 375 cm–1)\(_{{1/2}}^{^\circ }\) of lutetium ionization is studied for 175Lu, 176Lu, and 177Lu isotopes using the photoionization laser spectroscopy method. Values of the magnetic dipole (A) and electric quadrupole (B) interaction constants are determined, as well as the energies, the isotope shifts, and the radiative lifetimes for the 5d6s7s4D3/2 and (53 375 cm–1)\(_{{1/2}}^{^\circ }\) levels.