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Investigation of thermal neutron detection capability of a CdZnTe detector in a mixed gamma-neutron radiation field

Yücel H., Narttürk R. B., Zümrüt S., Gedik G., Karadag M.

Nukleonika

2018

Vol. 63, No. 3

59--64

The aim of this study was to investigate the thermal neutron measurement capability of a CdZnTe detector irradiated in a mixed gamma-neutron radiation fi eld. A CdZnTe detector was irradiated in one of the irradiation tubes of a 241Am-Be source unit to determine the sensitivity factors of the detector in terms of peak count rate (counts per second [cps]) per neutron flux (in square centimeters per second) [cps/neutron•cm–2•s–1]. The CdZnTe detector was covered in a 1-mm-thick cadmium (Cd) cylindrical box to completely absorb incoming thermal neutrons via 113Cd(n,γ) capture reactions. To achieve, this Cd-covered CdZnTe detector was placed in a well-thermalized neutron fi eld (f-ratio = 50.9 ± 1.3) in the irradiation tube of the 241Am-Be neutron source. The gamma-ray spectra were acquired, and the most intense gamma-ray peak at 558 keV (0.74 γ/n) was evaluated to estimate the thermal neutron fl ux. The epithermal component was also estimated from the bare CdZnTe detector irradiation because the epithermal neutron cutoff energy is about 0.55 eV at the 1-mm-thick Cd filter. A high-density polyethylene moderating cylinder box can also be fi tted into the Cd fi lter box to enhance thermal sensitivity because of moderation of the epithermal neutron component. Neutron detection sensitivity was determined from the measured count rates from the 558 keV photopeak, using the measured neutron fluxes at different irradiation positions. The results indicate that the CdZnTe detector can serve as a neutron detector in mixed gamma-neutron radiation fields, such as reactors, neutron generators, linear accelerators, and isotopic neutron sources. New thermal neutron filters, such as Gd and Tb foils, can be tested instead of the Cd filter due to its serious gamma-shielding effect.

Ultrasound and Microwave Aided Natural Dyeing of Nettle Biofibre (Urtica dioica L.) with Madder (Rubia tinctorum L.)

Yavaş A., Avinc O., Gedik G.

Fibres & Textiles in Eastern Europe

2017

Vol. 25, no. 4 (124)

111--120

In this study, eco-friendly 100% nettle bast bio-fibre fabric was dyed with eco-friendly natural dye, madder (Rubia tinctorum L.), using alternative dyeing methods such as ultrasound and microwave energy. Dyeings were performed with conventional-exhaustion, ultrasound and microwave methods using green tea and alum as mordants. The colorimetric, colour fastness properties and FTIR-ATR spectra of the nettle-biofibres dyed were investigated. Although the colour strengths of the microwave and ultrasound energy-aided dyeings were not as high as in conventional dyeings, the usage of microwave-energy in dyeing is important in terms of shortening the process time. All dyed nettle fabrics exhibited very high and commercially acceptable wash, dry-rub, alkaline-perspiration, acidic-perspiration and water fastness properties. Overall the conventional and ultrasound dyeing methods caused slightly higher light fastness than the microwave assisted dyeing method.

W pracy wykonane z włókien pokrzywy dzianiny barwiono ekologicznym naturalnym barwnikiem kraplak (Rubia tinctorum L.) przy użyciu ultradźwięków i mikrofal. Barwienie przeprowadzono stosując jako zaprawę farbiarską zieloną herbatę i ałun. Zbadano właściwości kolorymetryczne, trwałości koloru i widma FTIR-ATR wybarwionych włókien. Stwierdzono, że mimo, iż efekt barwienia przy użyciu mikrofal i ultradźwięków nie był tak silny, jak w przypadku tradycyjnego barwienia, to użycie mikrofalal wpływa na skrócenie czasu procesu. Wszystkie barwione wyroby wykazały bardzo wysokie i dopuszczalne w handlu trwałości na: pranie, pocieranie na sucho, potliwość kwaśną i alkaliczną oraz trwałość na wodę. Stwierdzono, że konwencjonalne i ultradźwiękowe metody barwienia powodowały nieco wyższą odporność na światło, niż barwienie przy użyciu mikrofal.