What happens if you put a 440 GeV proton beam pulse into a trough of tungsten powder in a helium environment?
A Technology Department initiative, supported by ASTeC, is proposing tungsten powder as a generic high Z target, e.g. as an alternative to the baseline mercury jet for a future neutrino factory. The result looks dramatic, but it is nowhere near as dramatic as what happens if you do the same with mercury (although in that case it is damped with a magnetic field). The results are in line with CFD simulations the group carried out for the helium expansion through a porous medium, although some work is now required to fit the simulations to the actual beam parameters.
The bright light in the centre is the laser light from a Laser Doppler Vibrometer, which was used to measure the difference between the stress wave generated in the powder container and an outer container (which will only see secondaries but no impact from the powder itself).
Further studies of the the LDV and video data are required to make proper conclusions, but initial indications are that the inner wall was not subjected to anything extreme.
The project team consisted of:
It is hoped to 'donate' the irradiated tungsten powder to PSI for further study.
Video footage can be viewed on YouTube (link opens in a new window)