A Paradigm Shift in nuclear spectrum analysis Alpha spectrometry 2015 A Paradigm Shift in nuclear spectrum analysis Paper By Dr. W. Westmeier, K. Siemon, IEEE Transactions on Nuclear Science, Vol. 59/4 (2012) 1296 New programming strategies : Physics, no Numerology for: - peakshapes - shape of baseline - shape of background - resolution function (no SQRT) - true coincidence losses - …..other Fuzzy logic for: - regioning - height of BGND before and after region - peaksearch - peakfit - repeated fit - various methods (Gauss, AWMI, Sieder, ..) - nuclide assignment - …..other

α-particle spectrometry Alpha spectrometry 2015 α-particle spectrometry • ALPS software can quantify even very complex and overlapping peaks • yields quantitative isotope activities • tracer analysis is integrated in the software • a very complete library (390 nuclides with 1270 lines) is available

After our Paradigm Shift extreme analyses became possible Alpha spectrometry 2015 After our Paradigm Shift extreme analyses became possible Quantitative separation of peaks from 239Pu and 240Pu

Quantitative separation of peaks from 239Pu and 240Pu Alpha spectrometry 2015 Quantitative separation of peaks from 239Pu and 240Pu

Fit of very complex and overlapping peak multiplett Alpha spectrometry 2015 Fit of very complex and overlapping peak multiplett Example: old 231Pa source with all its progeny

Fit of dried drop sample from river water Alpha spectrometry 2015 Fit of dried drop sample from river water Example: 1l river water preconcentrated to 1 ml, 200 µl drops dried on sample plate. 238U and (234U+230Th+226Ra) are found. 238U contents in river is 0.8 Bq/l

Fit of powdered granite sample, grain size ≥80 µm Alpha spectrometry 2015 Fit of powdered granite sample, grain size ≥80 µm Example: approx. 1 gram of granite powder was measured in a gridded ionisation chamber for over five days. 238U and 232Th progeny is completely quantified

Fit of filter paper sample from city air at main road Alpha spectrometry 2015 Fit of filter paper sample from city air at main road Example: 1“ dia. filter paper was loaded for 1 day and measured directly after 42h waiting time. 212Bi and 212Po are quantified yielding the 220Rn (thoron) concentration in the air. Note β-α coincidences above channel 450

Fit of ALGADE air sampler filter paper (1 month sampling) Alpha spectrometry 2015 Fit of ALGADE air sampler filter paper (1 month sampling) Example: filter paper was loaded for 1 month and measured directly with PIPS. 238U and all progeny are quantified - no chemistry, no sample preparation

Modern α-spectrometry can do it all with ALPS Alpha spectrometry 2015 Modern α-spectrometry can do it all with ALPS High-precision analysis of spectra from thin samples Quantitative data through use of tracer nuclides Separation of peaks that were impossible before Analysis of spectra from thick samples Quantification through calculated efficiency Very simple sample preparation - drying of drop samples - ashing of organic material - grinding of solids