In the LOEWE research cluster "Nuclear photonics - laser-generated particle beams for fundamentals and applications", scientists at the TU Darmstadt are investigating how modern laser systems can be used to develop novel particle sources and use them experimentally. Her work combines laser technology, accelerator research and nuclear physics. New sources of intense neutron and gamma rays allow new insights into the structure of matter and promise great application potential in research and development, in industry and technology. 

LOEWE Nuclear Photonics riddle: 

Imagine that we can focus all the light that falls on the earth onto one area with an oversized magnifying glass. Approximately how large does this area have to be so that we can achieve a similar radiant power per area as with the PHELIX laser here in the experiment at GSI? As big.... 

a) as a house roof. 

b) as a well-sharpened pencil point. 

c) as an atomic nucleus itself. 

Have fun & good luck with the solution!