Emulsion photograph showing the tracks of various cosmic ray nuclei,ranging from a hydrogen nucleus to an iron nucleus. The more protons a nucleus contains,the higher its positive electric charge & the greater its ability to ionise; the more it ionises,the denser its track in emulsion. Hydrog- en has 1 proton & produces a barely visible track. Ionisation depends on the square of the charge; so lithium's 3 protons have 9 times hydrogen's charge & produce a track 9 times denser. Iron,with 26 protons,produces a track 676 times denser than hydrogen. The wispy strands that adorn the denser tracks are "delta rays" - electrons knocked out of atoms in the emulsion by the passing nucleus | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Powell, Fowler & Perkins |
Taille de l’image : | 5052 px × 3381 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |