Neutron Depth Profiling

Some elements produce charged particles with characteristic energy in neutron interactions.

 

principles of ndp

 

When these elements are distributed near a surface, the particle energy spectrum is modulated by the distance the particle traveled through the surface.  NDP uses this information to determine the distribution of the elements as a function of distance to the surface.

ndp sensitivity
An illustration of equipment setup for NDP, with the beam exiting the reactor from the left and illuminating the sample in a vacuum chamber:

ndp graphic

 

A spectrum generated by assessing a sample from the National Institute for Standards Technology:

 

ndp srm93a