Alpha spectrometric characterization of thin ²³³U sources for ^229(m)Th production

Abstract

Four different techniques were applied for the production of 233U alpha recoil ion sources, providing 229Th ions. They were compared with respect to a minimum energy spread of the 229Th recoil ions, using the emitted alpha particles as an indicator. The techniques of Molecular Plating, Drop-on-Demand inkjet printing, chelation from dilute nitric acid solution on chemically functionalized silicon surfaces, and self-adsorption on passivated titanium surfaces were used. All fabricated sources were characterized by using alpha spectrometry, radiographic imaging, and scanning electron microscopy. A direct validation for the estimated recoil ion rate was obtained by collecting 228Th recoil ions from 232U recoil ion sources prepared by self-adsorption and Molecular Plating. The chelation and the self-adsorption based approaches appear most promising for the preparation of recoil ion sources delivering monochromatic recoil ions.

Equivalent circuit of a silicon–lithium p–i–n nuclear radiation detector

“…The simulation results of the obtained model using the Monte Carlo method show satisfactory results. The obtained alpha-decay spectra coincide with the experimental data shown in 45 – 47 . Theoretical calculations of FWHM closely related with calculation of Fano factor.…”

Actinide and lanthanide thin-layer developments using a drop-on-demand printing system

“…By combining different solvents and different backings (metals, polymers, carbon substrates, etc. ), these surfaces can be modified [10,11] and different wetting behavior of the individual drops can be achieved. This also has to be adapted and optimized for the respective target, depending on whether individual, separated deposits are required or whether the backing needs to be covered over as large an area as possible.…”

The process of molecular plating and the characteristics of the produced thin films – What we have learned in 60 years and what is still unknown

“…MP produces uniform thin films with an even distribution of the deposited element. Such layers found widespread applications, e.g., as targets in ion beam experiments, as recoil sources, or as α-particle sources [3][4][5][6][7][8][9][10][11][12]. One example is the synthesis of superheavy elements (SHE), which can be produced in the nuclear fusion of a light projectile with a heavy target nuclide.…”

“…Typical isotopes like 244 Pu, 248 Cm or 249 Bk are only available in small quantities, rendering production methods with high yields necessary. Therefore, MP has become the standard method for producing these targets [3,11,12]. For this application, the method works reliable up to film thicknesses of ≈ 800 µg/cm 2 , with yields of usually over 90 % [2,3,4].…”