Production of 203Pb from enriched 205Tl using deuteron beams.

Lead-203 is a SPECT emitter that can be used in theranostic applications as an imaging counterpart of lead-212 which is intended to be used for alpha therapy as lead-212/bismuth-212 in-vivo generator. In our study, we explore the production of lead-203 using enriched thallium-205 target irradiated by a deuteron beam. Excitation functions of deuteron induced reactions leading to the formation of 204m,203m2+m1+g,202m,201m+gPb, 202Tl and 203m+gHg isotopes were determined experimentally in the energy range from 21 MeV to 34 MeV. Cross sections were measured using the stacked foils technique and a set of two monitor foils, natNi and natTi for beam intensity evaluation. The experimental excitation functions of the investigated reactions were compared with the published data and also with the TENDL-2021 nuclear database. From our experimental data, we calculated lead-203 thick target yield in the energy range between 30 MeV and 32.5 MeV to be 56.7 MBq/µAh ±6.1 MBq/µAh. This value is compatible with large batch production showing that deuteron beams can be used for a routine production process. However, special attention must be paid to 203Hg and other lead contaminants.

Study of terbium production from enriched Gd targets via the reaction 155Gd(d,2n)155Tb.

The terbium (Tb) family has attracted much attention in recent years thanks to the diagnostic and therapeutic applications of the quadruplet 149Tb, 152Tb, 155Tb and 161Tb. However, the scarce availability of Tb radioisotopes is one of the main reasons hindering its clinical applications. To increase its availability, this work proposes to use enriched gadolinium (Gd) targets to produce some Tb radioisotopes (149Tb, 152Tb, and 155Tb) via deuteron-induced reactions in cyclotrons. The production of the Auger and gamma emitter 155Tb was chosen as a case study because the 155Gd enrichment (92.8%) is the highest available from all Gd stable isotopes. The involved reaction is 155Gd(d,2n)155Tb. Using enriched thin Gd-containing targets, cross-sections of the reactions 155Gd(d,x)153,154,155,156Tb have been measured at the GIP ARRONAX cyclotron facility with a beam energy ranging from 8 MeV to 30 MeV. This measurement allows for estimating the production yield and the purity of 155Tb, and for determining the irradiation parameters for large production batches. A thick enriched 155Gd2O3 target has been then irradiated with an incident energy of 15.1 MeV and a beam current of 368 nA for 1 h. The production yield of 155Tb is 10.2 MBq/µA/h at End Of Bombardment (EOB) and the purity is 89% after 14 days of decay. These experimental values are consistent with estimation based on measured cross-sections. A comparison of the deuteron-induced and proton-induced production routes is also presented in this paper.

Electrochemical co-deposition of Ni-Gd2O3 for composite thin targets preparation: Production of 155Tb as a case study.

In the last years, 155Tb has attracted enormous interest due to its potential role in theranostics in nuclear medicine. To estimate its production yield, the aim of this study was to develop a method to prepare thin Gd-enriched-containing targets aimed at the 155Gd(d, 2n)155Tb nuclear cross section measurement. To this end, the electrochemical co-deposition method has been chosen to manufacture Ni-Gd2O3 composite targets. Several process parameters that have an impact on the deposit quality, have been investigated to increase the incorporation of Gd mass (up to 3 mg). To validate the concept, seven targets made by natural Gd were irradiated with deuteron beams at the GIP ARRONAX facility cyclotron, with an energy range ranging from 8 MeV to 30 MeV to extract the cross section values by using the stacked-foils method. Results obtained turned out to have great consistency with existing published data thus validating the proposed method. Therefore, an alternative target manufacturing concept aimed at cross section measurement is presented in this work.

Is 70Zn(d,x)67Cu the Best Way to Produce 67Cu for Medical Applications?

The pair of copper radionuclides 64Cu/67Cu (T1/2 = 12. 7 h/61.8 h) allows, respectively, PET imaging and targeted beta therapy. An analysis of the different production routes of 67Cu with charged particles was performed and the reaction 70Zn(d,x) route was identified as a promising one. It may allow the production of 67Cu without 64Cu. The production cross section has been measured up to 28.7 MeV. Measurements were done using the well-known stacked-foils technique using 97.5% enriched 70Zn homemade electroplated targets. These measurements complement at higher incident energies the only set of data available in nuclear databases. The results show that using a 26 MeV deuteron beam and a highly enriched 70Zn target, it is possible to produce high purity 67Cu comparable to that obtained using photoproduction. This production route can be of interest for future linear accelerators under development where mA deuteron beams can be available if adequate targetry is developed.

THE RADIOBIOLOGICAL PLATFORM AT ARRONAX.

The cyclotron ARRONAX can deliver different types of particles (protons, deuterons, alpha-particles) in an energy range up to 68 MeV. One of its six experimental halls is dedicated to studying the interactions of radiation with matter including living matter. A horizontal beamline for cell irradiation has been setup and characterized. The radiobiological characterization was done in terms of V79 cells survival after irradiation with 68 MeV protons. The results demonstrate that radiobiological studies can be successfully performed confirming the high potential of the facility.

Cyclotron production of 67Cu: A new measurement of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga nuclear cross sections

The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.

Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.

Cyclotron production of 67Cu: A new measurement of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga nuclear cross sections / Producción de 67Cu en ciclotrón: una nueva medición de secciones eficaces nucleares de 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga

Abstract The cross sections of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to alow-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%)was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga.Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu,68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the nuclear reaction code TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.

Resumen Las secciones eficaces de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga se midieron en la instalación ARRONAX utilizando el ciclotrón 70 MeV, con especial atención a la producción del radionucleidos teranóstico 67Cu. El material enriquecido 68Zn se galvanizó sobre soporte de plata y se expuso a un haz de protones de baja intensidad utilizando un blanco de láminas apiladas. Como los radionucleidos 67Cu y 67Ga tienen periodos de semidesintegración y líneas γ similares (ambos se desintegran a 67Zn), un proceso radioquímico dirigido a la separación Cu / Ga fue obligatorio para evitar interferencias en las mediciones de espectrometría γ. Se desarrolló un procedimiento químico simple con una alta eficiencia de separación (> 99%) durante cada procesamiento de la lámina, gracias a los isótopos trazadores 61Cu y 66Ga. Las secciones eficaces nucleares se midieron en el rango de energía de 35-70 MeV utilizando reacciones de referencia recomendadas por el Organismo Internacional de Energía Atómica (OIEA) para monitorear el flujo del haz. Al comparar con los datos de la literatura, se observó una buena concordancia en general con la tendencia de las reacciones nucleares, particularmente con las últimas mediciones, pero se obtuvieron valores ligeramente inferiores en el caso de 67Cu. Los resultados experimentales de las reacciones 68Zn (p, 2p) 67Cu, 68Zn (p, 2n) 67Ga y 68Zn (p, 3n) 66Ga también se compararon con los valores teóricos estimados usando el código de reacción nuclear TALYS. El rendimiento de producción del radionucleido teranóstico 67Cu se estimó considerando los resultados obtenidos en este trabajo.