Measurement of continuous degradation of a stripper foil during ths operation with 300 kW beam power in the 3-GeV RCS of J-PARC

Saha, P. K.; 吉本 政弘; 發知 英明; 原田 寛之; 岡部 晃大; 山崎 良雄; 金正 倫計; 入江 吉郎*

Journal of Radioanalytical and Nuclear Chemistry, 305(3), p.851 - 857, 2015/09

BB2014-1580.pdf:0.54MB

https://doi.org/10.1007/s10967-015-4023-7

In the 3-GeV RCS, we have clearly measured a continuous degradation of the stripper foil used for charge exchange injection. The measurement was carried out during six months operation with 300 kW. The foil at the injection beam spot was measured to be continuously thickening and it was more than 10% thicker as compared to its initial thickness indicating that a strong wrinkling or curling occurred at the foil edge even with present beam intensity. The missing H was also measured to be gradually increased due to the curling. It is thus a big issue for 1 MW operation as a missing H would increase the heat load on the waste beam dump. A foil thickening on the other hand increases the foil scattering beam loss. A foil thinning and pinhole formation caused by the radiation due to radiation are believed to signals for foil breaking and is also one big concern as beam intensity is increased. The present high precession measurement technique is believed to play an important role for determining a proper timing for foil replacement in order to ensure a stable operation of the RCS.

Improving material properties and performance of nuclear targets for transmutation-relevant experiments

Vascon, A.; Wiehl, N.*; Runke, J.*; Drebert, J.*; Reich, T.*; Trautmann, N.*; Cremer, B.*; Kgler, T.*; Beyer, R.*; Junghans, A.*; et al.

no journal, , 

TRAKULA is a joint research project of the German Federal Ministry of Science and Education (BMBF) whose main focus is on obtaining high-quality nuclear data relevant to the transmutation of radioactive waste. Fission cross section measurements on actinides, carried out as a part of the TRAKULA project, require well characterized and very homogeneous large-area actinide targets. Molecular plating is one of the most successfully applied techniques for the production of nuclear targets. The element of interest is electrodeposited from an organic medium with quantitative yields. Yet MP-produced targets are usually defective, characterized by surface cracks, and sometimes with poor structural rigidity. Such properties negatively affect the experiments to be performed. In order to produce optimum targets for TRAKULA, in the last years we have undertaken efforts to improve the quality of the obtained layers. The latest results of these studies will be reported, which allowed identifying those plating parameters that have a crucial influence on the homogeneity, structural rigidity, surface roughness, and morphology of the layers. The presentation will also demonstrate that nuclear targets perform differently depending on the properties of the layers. Finally, characterization analyses and preliminary results of the performance of the targets produced for the TRAKULA-related fission experiments will be shown.