(published April 2024)
Realization of ultra-pure material targets is the first of the STAR task goals, to allow for the measurement of low reaction yields, in which signals from parasitic reactions on impurities can limit experiments and must therefore be avoided.
In the STAR framework, targets are produced at LNS-INFN as well as at IFIN-HH (where also PLD and methallotermic reduction are available) via ion implantation, PVD methods (resistive heating and electron beam-based systems), cold rolling and tablet pressing techniques. Moreover, PVD is also available at LNL-INFN, while the University of Cologne laboratory can produce targets by PVD, electrolysis and cold rolling.
Standardized testing of the produced targets has been implemented and it is performed via radioactive sources and/or beam bombardment, and was also offered as a service for the community, including contaminant identification and stability tests.
Here we report about the target already tested under radioactive sources or beam bombardment, while details and further information are being prepared to be published in scientific journals.
@IFIN-HH (NAG group)
| Reaction to study | Compound | Thickness | Beam/source used | Results |
| 13C+16O | 13C on Ta backing | 130 and 150 nm | 16O beam | Ok for single irradiation of ~10 mC |
| 13C+16O | CeO2 on Al backing | 0.8 and 1 g/cm2 | 13C | Ok for single irradiation of ~10 mC |
| 13C+16O | Ta2O5 | 150 and 380 nm, with Ta backings of 0.25 and 0.02 mm respectively | 13C | Ta2O5 layer disappeared during irradiation. Further studies are needed. |
| 13C+19F | LiF | 1 mm | 13C | Ok but outgassing |
| 13C+19F | Ba2F | 1 mm | 13C | Ok but very fragile |
@LNS-INFN (AsFiN group)
| Reaction to study | Compound | Thickness | Beam/source used | Results |
| Fluorine background in New Jedi experiment | CaF2 on graphite backing | 150 μg/cm2 + 30 μg/cm2 (backing) | 241Am α-source | No damage reported |
| PTFE -(F2C-CF2)n– | 1 mg/cm2 | 241Am α-source @LNS and proton beam @UFJ-NPI | Resisted up to 200 nA of proton beam |
@LNL-INFN (SALVIA group)
| Reaction to study | Compound | Thickness | Beam/source used | Results |
| 16O(p,γ)17F | Ta2O5 | Several | Proton beam | Ok and regular areal density profile |
| 14N(p,γ)15O | TiN | |||
| 14N(p,γ)15O | TaN | |||
| 14N(p,γ)15O | ZrN |
These results testify how STAR has gathered European target laboratories in a context where they can learn from mutual experiences and cooperate for the first time.