Study of Radiophotoluminescence of Eu Doped CaSO4 Phosphor for Gamma Dosimetric Applications

CaSO4:Eu phosphor is synthesised by acid distillation method with varying synthesis parameters for studying its Radiophotoluminescence (RPL) properties for gamma absorbed dose measurements. Five phosphor samples are prepared by varying quantity of solvent, distillation temperature and reaction time. XRD, SEM, particle size analysis and photoluminescence studies are carried out. The characterisation study shows polycrystalline luminescent particles of average size varying from 35 μm to 55 μm. Characteristic emission of Eu3+ is observed around 590, 615 and 620 nm at 242 nm excitation. Gamma dose response of maximum Eu3+ PL intensity sample is studied in the range 10 cGy to 1000 cGy using Co-60 source. Gamma radiation exposure induces conversion of Eu3+ to Eu2+ giving luminescence at 385 nm with 320 nm excitation. Repetitive measurements of gamma exposed samples are carried out and no significant fading is observed within one week of post-irradiation. The phosphor has the potential to be used for gamma dosimetry

Evaluation of dose distributions in gamma chamber using glass plate detector

A commercial glass plate of thickness 1.75 mm has been utilized for evaluation of dose distributions inside the irradiation volume of gamma chamber using optical densitometry technique. The glass plate showed linear response in the dose range 0.10 Kilo Gray (kGy) to 10 kGy of cobalt-60 gamma radiation with optical sensitivity 0.04 Optical Density (OD) /kGy. The change in the optical density at each identified spatial dose matrix on the glass plate in relation to the position in the irradiation volume has been presented as dose distributions inside the gamma chamber. The optical density changes have been graphically plotted in the form of surface diagram of color washes for different percentage dose rate levels as isodose distributions in gamma chamber. The variation in dose distribution inside the gamma chamber unit, GC 900, BRIT India make, using this technique has been observed within ± 15%. This technique can be used for routine quality assurances and dose distribution validation of any gamma chamber during commissioning and source replacement. The application of commercial glass plate for dose mapping in gamma chambers has been found very promising due to its wider dose linearity, quick measurement, and lesser expertise requirement in application of the technique

Effects of gamma ray and neutron radiation on polyanilne conducting polymer

453-456Ionizing radiation effects such as neutron and gamma on conducting polyanilne have been studied for various doses varied from 6 to 504Gy and 15 to 41.9 kGy, respectively. Spectroscopic methods such as UV-Vis spectroscopy, X-ray diffraction, Raman spectroscopy and I-V measurements have been used to characterize the pristine and irradiated polyanilne samples. UV-visible spectroscopy shows a shift in the absorption edge towards visible region after irradiation, which can be correlated to the transition involved in these polymers and variation in the band gaps (Eg) using Tauc’s expression which indicate a decrease in band gap. XRD spectra revealed that crystallinity and particle size improve after irradiation, which could be attributed to cross-linking mechanism. The current voltage (I-V) characteristics have been carried out at room temperature using four probe set up and it has been found that polyaniline films show ohmic behaviour before and after irradiation. Moreover, conductivity improves after irradiation, which is due to enhancement in carrier concentration. Conducting polymers as a radiation sensor for gamma and neutron as well as for dosimetry aspects have been studied

Implementation Strategy for Optical Fiber Modbus-TCP Based Nuclear Radiation Detection Instrument for Nuclear Emergency

Abstract-Any detection of Nuclear emergency is prone to the EMP generated by the blast. Hence use of conventional wireless & wired sensor networks in such scenarios becomes very difficult. Thus an effective sensor network scheme is needed which effectively senses and communicates in such scenarios over an existing protocol. The proposed system offers such a scheme where Optical fiber based communication is used for immunity against EMP, while MODBUS-TCP protocol is used for faster communication over existing network protoco

Silicon PIN diode neutron dosimetry

813-816Silicon PIN neutron dosimeter has been developed by Defence Laboratory, Jodhpur. The device is a wide base, conductivity modulated PIN diode that response to fast neutrons in the range of interest (1 cGy to 1000 cGy). The study carried out at Defence Laboratory to evaluate different characteristics of the PIN diode as a neutron dosimeter has been presented

Effect of pre-irradiation deformation on thermoluminescence of divalent impurity doped alkali halide crystals

870-875<span style="font-size:13.0pt;mso-bidi-font-size: 12.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" ar-sa"="" lang="EN-IN">The effect of pre-irradiation deformation on the thermoluminescence (TL) of alkali halide crystals has been reported. The pre-irradiation deformation causes increase in the thermoluminescence intensity corresponding to both the TL glow peaks of alkali halide crystals. The dependence of TL intensity corresponding to first and second TL peaks on pre-irradiation deformation follows the relations… </span

High temperature thermoluminescence of gamma-irradiated copper activated silica glass and its application to dosimetry

The thermoluminescence (TL) glow curve, glow-spectrum and the TL-output versus gamma-irradiation dose relationship of a copper(I) activated silica glass have been studied. Considering the high thermoluminescence efficiency, long trap-storage capability, good TL reproducibility and relatively high dose-saturation limit of the glass, it is suggested that the material can be used as a good gamma-ray dosimeter in the dose range 4-400 Gy

Radiochromic behaviour of bromocresol green-polyethylene glycol system towards <img src='/image/spc_char/gamma2.gif' border=0>-radiation

837-839Active BCG-PEG radiochromic liquid system has been formulated for potential application as threshold dosimeter for gamma radiation that can be visually evaluated. PEG concentrations have been varied to see their effect on the radiation sensitivity of these systems. The response characteristics are monitored both visually and by UV-Vis spectrometry. The minimum visually detectable level achieved with the formulated solution is 0.2 kGy, where the solution showed a sharp colour change from green to yellow. The detection level could be moved to the higher side by increasing the concentration of PEG in the formulation. Preliminary dose dependence studies have been carried out in the range 0.3-7.5 kGy/hr

Radiological safety aspects in Californium-252 source transfer operation

798-801The methodology, radiological safety planning and technical experiences gained during the transfer of 1 mg of 252Cf neutron source from transport container to exposure facility have been reported. Hot mockups with dummy sources and radiation safety planning in advance have been observed as the main contributing factor in personal dose reduction and to increase the confidence level in radioactive source transfer in open condition. The doses received by the personnel during this procedure are in the range 0.15-0.30 mSv, which are well within the planned dose limit during operation (5 mSv). No accidental or emergency situation had arisen during the course of this task. Before any new high strength source expected to arrive in any institution, a full-scale mockup should be performed to ensure all members of the work team to understand their parts in the operation. Minimum possible persons should be involved in source transfer. Too many minds at a time should not be applied in such a hazardous operation. There should be only one supervisor at the site and no one except the supervisor should be allowed to give instructions and suggestions during the source loading or transfer procedure. Only expert and experienced radiation safety personnel with high confidence level should undertake such operations. All technical aspects and challenges faced during the source transfer have been highlighted