Proton-proton scattering at the Munich microprobe SNAKE gives the unique possibility for sensitive 3D hydrogen microscopy [1]. We have installed a new multicusp ion source for negative hydrogen ions manufactured by HVEE [2] at the Munich tandem accelerator. The aim is boosting the proton beam brightness and hence optimizing the microprobe's lateral resolution and its sensitivity in hydrogen detection. The source operates at the space charge limit at its extraction site and therefore enables an optimum emittance of 15-20 Am^(−2)rad^(−2)eV^(−1) and brightness at the principal limit for conventional ion sources. The emittance is two orders of magnitude larger than that of the ECR source that was used before in combination with charge exchange for negative hydrogen production. For injection into the tandem accelerator, the extraction current of up to 1.5 mA H− is reduced to about 10 μA. Thus, we only accelerate the high brightness core of the beam that is further restricted in size and divergence by micro slit systems in front of SNAKE. We present the performance of the installed source and show the beam characteristics at the focal plane of SNAKE. In addition we show first 3D hydrogen microscopy on geological samples with a new multi-strip detector matrix consisting of four 5x5 cm^2, 1 mm thick strip detectors in a configuration parallel to the beam. The new detector setup enables us to use up to 25 MeV of incoming protons stopping all scattered protons from proton-proton scattering in the detector.    «

Proton-proton scattering at the Munich microprobe SNAKE gives the unique possibility for sensitive 3D hydrogen microscopy [1]. We have installed a new multicusp ion source for negative hydrogen ions manufactured by HVEE [2] at the Munich tandem accelerator. The aim is boosting the proton beam brightness and hence optimizing the microprobe's lateral resolution and its sensitivity in hydrogen detection. The source operates at the space charge limit at its extraction site and therefore enables an o...    »