PMID- 28952615
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180727
LR  - 20180727
IS  - 1364-5528 (Electronic)
IS  - 0003-2654 (Linking)
VI  - 142
IP  - 20
DP  - 2017 Oct 9
TI  - Assessment of PGAA capability for low-level measurements of H in Ti alloys.
PG  - 3822-3829
LID - 10.1039/c7an01308f [doi]
AB  - The accuracy of low-level hydrogen measurements with prompt gamma-ray activation 
      analysis (PGAA) depends on identifying and accounting for all background H 
      signals, including interfering signals. At the cold-neutron (CN)PGAA facility at 
      the NIST Center for Neutron Research, the sources of background H signals were 
      investigated in the context of titanium-based matrices containing low-levels of H 
      (<300 mg H per kg Ti) with the measurements of prepared standards (mixtures of 
      polyvinyl chloride and titanium oxide) and Ti alloy (Ti6Al4V) samples. The 
      sensitivity ratio, defined as the ratio of the H signal to the Ti signal per unit 
      mass ratio of H in Ti, was determined (1) with the measurements of prepared 
      standards and (2) based on partial gamma-ray production cross sections and 
      full-energy detection efficiencies. The resulting calibrations from these two 
      approaches agreed within experimental uncertainty. A series of Ti alloy NIST 
      Standard Reference Materials (SRMs) previously certified for the H content (SRMs 
      2452, 2453, 2453a, 2454) were used as test cases, with the mass fractions 
      determined based on the sensitivity ratios derived from method 1 and method 2, 
      respectively. The results agreed with the certified values within experimental 
      uncertainties, validating the analysis performed on the new instrument with 
      newly-prepared standards at low H mass fractions (method 1), and with the 
      standard-independent analysis (method 2). Various sample mounting improvements 
      were made to lower the background H signal. Spectral interferences near the H 
      peak were identified as potential sources of bias and as a limiting factor in the 
      detection limit of H in Ti alloy samples.
FAU - Turkoglu, Danyal
AU  - Turkoglu D
AD  - National Institute of Standards and Technology, 100 Bureau Dr, Gaithersburg, MD, 
      USA. heather.chen-mayer@nist.gov.
FAU - Chen-Mayer, Heather
AU  - Chen-Mayer H
FAU - Paul, Rick
AU  - Paul R
FAU - Zeisler, Rolf
AU  - Zeisler R
LA  - eng
PT  - Journal Article
PL  - England
TA  - Analyst
JT  - The Analyst
JID - 0372652
EDAT- 2017/09/28 06:00
MHDA- 2017/09/28 06:01
CRDT- 2017/09/28 06:00
PHST- 2017/09/28 06:00 [pubmed]
PHST- 2017/09/28 06:01 [medline]
PHST- 2017/09/28 06:00 [entrez]
AID - 10.1039/c7an01308f [doi]
PST - ppublish
SO  - Analyst. 2017 Oct 9;142(20):3822-3829. doi: 10.1039/c7an01308f.