Development of uranium carbide targets V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Author’s list V.N. Panteleev, A.E. Barzakh, D.V. Fedorov, A.M. Ionan, V.S. Ivanov, K.A. Mezilev, F.V. Moroz, S.Yu. Orlov, Yu.M. Volkov , Petersburg Nuclear Physics Institute RAS, Leningrad district, Russia A. Andrighetto, A. Lanchais, G. Lhersonneau, L. Stroe, V. Rizzi, L.B. Tecchio, INFN, Laboratori Nationali di Legnaro, Viale dell' Universita 2, Legnaro (Padova), Italy R.Leroy, A.C.C Villari. N. Lecesne, J.Y. Pacquet, G. Gaubert, P. Jardin, M. Dubois, M.G. Saint Laurent, GANIL (Grand Accelerateur National d’Ions Lourds), Boulevard Henri Becquerel, BP 55027, F Caen Cedex 5, France S. Essabaa, O. Bajeat, C. Lau, Institute de Physique Nucleaire d’Orsay Groupe Source d’Ions, Batiment 106, Division Accelerateur, F Orsay Cedex, France M. Menna, INFN, Laboratori Nationali del Sud, via S.Sofia, , Catania, Italy V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Introduction We used for the targets a special uranium carbide with density of 11 g/cm 3. that is rather close to the theoretical mono-crystal density value (13.6 g/cm 3 ). Three month heating test of such high-density UC target has been carried out at the IRIS facility in the framework of a collaboration PNPI-LNL-GANIL-Orsay. We report test results of three high-density rod targets; a comparison between the yields and delay times from the long-lived target (LLT), from the reference target (RT) and an ionising target (IT). V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Target materials tested at IRIS

X-ray structure analysis of high density UC target material

Microstructure of high density UC target material

Schematic drawing of the target-ion source assembly used for the three- months heating test with the Long-Lived Target (LLT). The Reference Target (RT) has a similar construction, the only difference being the wall thickness of the target container: 0.25 mm for RT and 0.5 mm for LLT. The target material thicknesses were 6-8 g/cm2 V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Schematic drawing of the Ionising Target (IT). Once the produced species are evaporated, they undergo surface and electron beam ionisation in the volume of the target container. The electron beam is emitted by a cathode plate placed on the side of the extraction electrode V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Comparison of the Rb yields from the reference target RT (black triangles), the long-lived target LLT (black circles) and the ionisation target IT (open circles). The yields are normalized to a target thickness of 1 g/cm 2 and a proton beam intensity of 0.1 μA. Target temperatures were: T(RT) = 2050 °C; T(LLT) = 2050 °C, measure taken after three months of heating; T(IT) = 1900 °C V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Comparison of the Cs yields from the RT (black triangles), the LLT (black circles) and the IT (open circles). The same conditions as for previous figure V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Comparison of the In yields from the LLT before (open squares) and after (black circles) 3 months of heating at 2050 °C. The yields from the IT (stars) are plotted as well V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

Comparison of the delay times for 139 Cs (T 1/2 = 9.27 min) released from the RT, the LLT after three-months heating period and the IT V.N. Panteleev EURISOL Town Meeting, Caen, France November 2005.

The dependence of the target resistance on the heating time during a long-term heating test. The average temperature of the target was 2030 ± 30C V.N. Panteleev EURISOL Town Meeting, Caen, France, November 2005.

The LLT can be maintained for more than 2400 hours at a temperature of 2030 °C without appreciable changes in its main characteristics, as demonstrated by the yields and delay times of Rb, Cs and In radioactive isotopes. Since the target resistance remained practically stable during a long heating period, it gives the possibility to carry out similar long heating tests at higher target temperatures. Another important result is the construction of the used targets ensures a good reproducibility of the yields and release times for the nuclides investigated. The IT, a really new target construction, has been tested with success. It can be implemented not only for the production of easily volatile nuclides with low ionization potentials but also for the ion production of all elements evaporated from the target material. Conclusion

Microstructure of a new high density UC target (12 g/cm 3 )

The use of a new high density UC target material (12-13 g/cm 3 ) with the grain size of 20, 5 and 1 m, measuring the yields and delay times of the on-line produced species. Plans for the nearest future: