V.E. Aleynikov

Nanocrystalline Ba0.97Ca0.03SO4:Eu for ion beams dosimetry

Nanoparticles of Ba0.97Ca0.03SO4:Eu have been irradiated by 48 MeV Li3+, 75 MeV C6+, and 90 MeV O7+ ion beams with a fluence range of 1×109−1×1013 ion/cm2. The thermoluminescence (TL) glow curves along with the response curves of this nanophosphor have been investigated and compared with those of the corresponding microcrystalline samples. TL glow curve of the nanophosphor exposed to γ-rays has also been included in the letter with the aim of reporting some of the comparative measurements. The glow curves of the ion-beam irradiated nanomaterials are similar in their shapes to those induced by gamma rays, with a shift in the peak positions to the higher temperature side by around 30 K. The TL intensity of the ion-beam irradiated nanomaterials is found to decrease, while going from low to high atomic number (Z) ions (i.e., Li3+→O7+). Similar trend was also observed in the linearity of the TL response curves. The response curve of Li ion irradiated nanomaterials is sublinear in the whole range of studied flu...

Nanoparticles of K2Ca2(SO4)3:Eu as effective detectors for swift heavy ions

The modification of thermoluminescence (TL) and photoluminescence (PL) properties of K2Ca2(SO4)3:Eu nanoparticles by swift heavy ions (SHI), irradiation is studied. Pellets form of the nanomaterials were irradiated by 48 MeV Li3+, 75 MeV C6+, and 90 MeV O7+ ion beams. The fluence range is 1×109−1×1013 ions/cm2. The modification in TL glow curves of the nanomaterials irradiated by Li3+, C6+, and O7+ ion beams are essentially similar to those induced by γ-ray irradiation. These glow curves have single peaks at around 427 K with a small variation in their positions by around ±3 K. The TL intensity of the ion beams irradiated nanomaterials is found to decease, while going from low to high atomic number (Z) ions (i.e., Li3+→O7+). The TL response curve of the pellets irradiated by Li3+ ions is linear in the whole range of studied fluences. The curves for C6+ and O7+ irradiated samples are linear at lower fluences (1×109–1×1012 ion/cm2) and then saturate at higher fluence. These results for the nanomaterials are...

Nanorods of LiF:Mg,Cu,P as Detectors for Mixed Field Radiations

Nanocrystalline powder of LiF: Mg,Cu,P phosphor has been synthesized by the chemical coprecipitation technique. Shape and size of these nanomaterials were observed by transmission electron microscope and atomic force microscope. The particles are of rod shapes having diameters from 50 to 80 nm and lengths varying within the range 0.4-0.7 mum. Pellets of these nanorods were irradiated by 48 MeV7Li3+ ions at different fluences in the range 1times1011-1times1014 ions/cm2 (with corresponding doses in the range 0.679-679 kGy) and their thermoluminescence (TL) properties have been studied. The TL glow curves are observed to have prominent peaks at around 588 K along with smaller one at around 410 K. The TL intensity of the former is found to increase with increasing the fluence, while that of the latter decreases. These behaviors are in contrast with those of the peaks induced by 137Cs gamma-rays. This modification in case of irradiation by ion beam has been attributed to the change in population of the luminescent/trapping centers due to the use of highly energetic ions. From these results, it is suggested that the nanorods of LiF:Mg,Cu,P might be used as detectors for mixed fields radiations such as space radiations.

Thermoluminescence of BaSO4 : Eu irradiated with 48 MeV Li3+ and 150 MeV Ag12+ ions

The effects of irradiation by 48 MeV Li 3+ and 150 MeV Ag 12+ ion beams on the thermoluminescence (TL) of BaSO 4 Eu phosphor are studied. Samples in the form of pellets were exposed to different fluences in the range 1 x 10 9 -5 x 10 11 ions cm -2 . The modifications in TL glow curves of the materials irradiated by lithium (Li) and silver (Ag) beams are essentially similar to those induced by γ-ray irradiation. There is a significant variation in the relative intensity between the main glow peak at 497 K and the small shoulder at 465 K. This variation is more dominant in the samples irradiated by Ag ions. This has been attributed to the change in the population of the luminescent/trapping centres (LCs/TCs) during the bombardment by high-energy heavy ions. The relative TL efficiency values of BaSO 4 Eu to 48 MeV Li and 150 MeV Ag ion beams have been measured relative to 0.662 MeV γ-rays of 137 Cs and are found to be 0.374 and 0.0017, respectively. It is found that BaSO 4 Eu phosphor is suitable for recording irradiation from light ions (Li) as well as heavy ions (Ag) as it shows linearity in its TL responses over wide ranges of fluences of ion beams. It is linear in the ranges 1 × 10 9 -1 × 10 11 and 1 × 10 9 -1 × 10 10 ions cm -2 for Li and Ag ion beams, respectively. This property along with its low fading make BaSO 4 : Eu phosphor a good candidate to be used as a dosimeter for cosmic rays and medical applications.

Nanocrystalline BaSO{sub 4}:Eu For Dosimetry of Proton Beams

Nanocrystalline BaSO4 doped with Eu, was prepared by the Chemical Co‐precipitation method. The particle size was calculated by the broadening of the XRD peaks using Scherrer’s formula with particle size around 45 nm. Samples in the form of pellets were irradiated by 150 MeV proton beam with dose range of 0.1 Gy to 325 Gy. Thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. It has been found that there are two prominent TL glow peaks at 460 K and 495 K. The TL response is sublinear below 1 Gy, linear in the range 1 Gy to 200 Gy and then becomes supralinear for higher doses. The wider linear TL response of nanocrystalline BaSO4:Eu and low fading makes it a superior candidate as a dosimeter to be used for detecting the doses of protons for its various applications in the field of space, therapy and research.

Nanocrystalline K2Ca2(SO4)3: Eu for proton beam dosimetry

This paper investigates the Thermoluminescent response of nanocrystalline K2Ca2(SO4)3: Eu, prepared by Co-precipitation technique to 150 MeV proton beam. The particle size was calculated to be 45 nm by the broadening of the XRD peaks using Scherrers formula. Samples in the form of pellets were irradiated by 150 MeV proton beam with dose range of 0.1 Gy to 325 Gy. Thermoluminescence (TL) glow curves of the irradiated samples were recorded and studied. It has been found that the phosphor shows a characteristic single peak at around 420 K. The TL response is linear in the range upto 200 Gy and then saturates for higher doses. The wider linear TL response of nanocrystalline K2Ca2(SO4)3: Eu and low fading makes it a superior candidate as a dosimeter to be used for detecting the doses of protons beams for its various applications in the field of space, therapy and research.