1. 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

2. 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

3. 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

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

5. 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

6. 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 U and (234U+230Th+226Ra) are found. 238U contents in river is 0.8 Bq/l

7. 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

8. 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

9. 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 U and all progeny are quantified - no chemistry, no sample preparation

10. 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