The applicants aim to perform the most authoritative measurements of NCS profiles by controlling and precisely quantifying everything to do with the sample. In July 2008 we studied the NCS profile from free H2 gas at p=50 bar and T=295 K. In contrast to previous results and theoretical expectations, our very careful measurement on H2 revealed that the breadth of the H peak in J(y) exhibits a strong decrease with increasing momentum transfer, i.e. ¿violation of y-scaling¿. This effect is clearly visible to the eye in the as-measured NCS profiles. We repeated the experiment in July 2009, at 44 K and 295 K, and confirmed our previous results. Because the violation of y-scaling was unexpected and is unexplained, there is a need for as much knowledge as possible about the phenomenon. For this reason, this proposal requests beam time to study D2. Novel theoretical insights are also expected.