Unfolding algorithms for neutron depth profiling:probability iteration, SVD solving least square, linear regularization(LR) and constrained linear reqularization(CLR) are studied. All algorithms are applied for both under-determined and over-determined equations, and results are compared and discussed. Due to iterative processes, probability iteration and CLR could not work well in the case that sources intensities change sharply. LR is unstable as unfolding range is chosen arbitrarily, which can be constrained by CLR. A practical spectrum of NDP experiment is unfolded by algorithms. LR could not restrain stochastic errors caused by statistical fluctuation, while other algorithms show good unfolding results and agree well with references.

To get element quantity of a sample in neutron depth profiling,method of standard sample's general ions quantity in measurement scope is used to relative quantity analysis technology. The least square method is used. According to actual experiment condition and on the base of energy width modification and depth distribution unfolding analysis,formula of quantitative analysis is deduced and programmed with FORTRAN. Experiment simulation is used to quantify10B element of a sample to validate feasibility of the method. It shows that quantifying element of a sample by comparing with normal sample is feasible.