Development of X-ray Spectrometry for Nuclear Decay

Data Applications at IFIN-HH

Aurelian LucaHoria Hulubei National Institute of Physics

and Nuclear Engineering (IFIN-HH), Magurele, Romania

• Work performed in the frame of the joint research project IFA Romania – CEA France no. C2-05/2012 (collaboration between IFIN-HH and CEA, DRT/LIST/LNHB, 2012-2015): “Creation of national standards for some emerging pharmaceutical radionuclides to ensure the radioprotection of patients and medical staffs”

• A new high-resolution spectrometry system is necessary at IFIN-HH for measurements of low energy γ- and X-rays emitted by the radionuclides to be studied for the project (177Lu, 186Re) and other applications.

• The energy range (3…50) keV is of particular interest, as it cannot be covered by the existing high-resolution HPGe gamma-ray detector used in the Radionuclide Metrology Laboratory (RML) since 2007.

• The following components (Canberra) were purchased, assembled and preliminary tested:

-Si(Li) detector (preamplifier included);-Digital spectrometer;-Notebook computer with GENIE2000 S511 and OriginPro v.9.0 (2012) software.

• Si(Li) detector SL30170, with charge sensitive preamplifier model 2008B and cryostat model 7500: active diameter 6.2 mm, active area 30 mm2, 3 mm thick, 5 mm distance from the Be window (0.025 mm). High voltage: -500 V dc.Manufacturer specifications for a time constant 12 s: FWHM=166 eV and FWTM=306 eV, for 5.9 keV (55Fe)

• Digital spectrometer DSA 1000: DSP, MCA- 16384 channels, PHA/MCS, pole zero adjustment, pile-up rejector and dead time correction, pulse shaping, USB/RS-232, support for GENIE 2000 v.2.0A

Experimental Results• Radioactive standard sources available:55Fe [5.89 keV (25.02(30)%) XK and (6.49…6.54) keV

(3.40(7)%) XK], T1/2=2.747(8) years 57Co [6.4 keV (50%), 7.1 keV (7%); 14.4 keV (9%)] 241Am [XL 12-22 keV (38%), 26.3 keV (2.4%) and

59.5 keV (36%)].55Fe point standard source: produced by RML; code SEG

7-872, activity: (3793±152) Bq, k=2 (27/02/2013); 7200 s measurement time; 50 mm distance above the detector

Experimental Results-A spectral anomaly caused by a wrong electronic setup

was corrected by the specialists from Canberra Romania (2013). After the correction:

• Integral background counting rate (1022 channels): 0.234 counts/s

• Experimental FWHM: 0.23 keV at 5.7 keV.• Detection efficiency for the mean energy (5.96 keV):

0.87·10-2 s-1 Bq-1

X-ray Spectra: 55Fe, 241Am

5.9 keV

6.5 keV

• Resolving (deconvolution) complex X-ray and low energy -rays spectral regions (e.g. 241Am)

• Testing different types of sources to check the influence of self-absorption

• Training for the use of GENIE 2000 software

Future Improvements

THANK YOU !