10 research outputs found
The Calculation of Mass Attenuation Coefficients of Well-Known Thermoluminescent Dosimetric Compounds at Wide Energy Range
No full text32nd International Physics Congress of Turkish-Physical-Society (TPS) -- SEP 06-09, 2016 -- Bodrum, TURKEYThe photon mass attenuation coefficients of LC BaSO3, CaCO3 and CaSOzi thermoluminescent dosimetric compounds at 100; 300; 500; 600; 800; 1,000; 1,500; 2,000; 3,000 and 5,000 keV gamma-ray energies were calculated. For this purpose, FLUKA Monte Carlo (MC) program which is one of the well-known MC codes was used in this study. Furthermore, obtained results were analyzed by means of ROOT program. National Institute of Standards and Technology (NIST) values were also used to compare the obtained theoretical values because the mass attenuation values of the used compounds could not found in the literature. Calculated mass attenuation coefficients were highly in accordance with the NIST values. As a consequence, FLUKA was successful in calculating the mass attenuation coefficients of the most used thennoluminescent compound.Turkish Phys SocEge UniversityEge University [2014 FEN 026]The Author thanks to Dr. E. Pilicer for his help in the calculation procedure and to Dr. C. Celiktas for his precious contribution to the study. This work was supported by Scientific Research Project of Ege University under Project No. 2014 FEN 026
Mass attenuation coefficient calculations of different detector crystals by means of FLUKA Monte Carlo method
No full textCalculations of gamma-ray mass attenuation coefficients of various detector materials (crystals) were carried out by means of FLUKA Monte Carlo (MC) method at different gamma-ray energies. NaI, PVT, GSO, GaAs and CdWO4 detector materials were chosen in the calculations. Calculated coefficients were also compared with the National Institute of Standards and Technology (NIST) values. Obtained results through this method were highly in accordance with those of the NIST values. It was concluded from the study that FLUKA MC method can be an alternative way to calculate the gamma-ray mass attenuation coefficients of the detector materials
Enhancement of Energy Spectra through Constant Fraction Timing Method
No full text32nd International Physics Congress of Turkish-Physical-Society (TPS) -- SEP 06-09, 2016 -- Bodrum, TURKEYThe energy spectra of Cs-137, Co-60 and C-14 were achieved by using the spectrometers composed of different types of detectors. In this work, constant fraction timing method was used to enhance their energy spectra. Energy resolution values of Cs-137 and Co-60 gamma energy spectra were improved through this timing method. In addition, electronic noise appeared in the energy spectrum of C-14 was discriminated through the timing method, leading to clear beta energy spectrum.Turkish Phys SocEge UniversityEge University [2014 FEN 026, 2014 FEN 053]This work was supported by Scientific Research Projects of Ege University under Project No. 2014 FEN 026 and 2014 FEN 053
Spinthariscope Based MPPC Alpha Detector
No full textAn alpha particle detector was constituted by favour of an MPPC (Multi-Pixel Photon Counter) using a ZnS(Ag) sheet named spinthariscope. It was coupled to front side of the MPPC's window. Since obtained Ra-226 alpha spectrum by the MPPC was highly noisy, a timing measurement method (constant fraction discrimination) was implemented to overcome this unfavourableness. Obtained results showed that the used timing method was quite successful for acquiring the noise discriminated alpha spectrum and improving the alpha peak energy resolution. It was concluded from this proposed experimental technique that an MPPC could be used as an alpha detector via a spinthariscope and improved the alpha peak resolution using the mentioned timing measurement method.Scientific and Technological Research Council of TURKEY [121F012]This work was supported by The Scientific and Technological Research Council of TURKEY under project no. 121F012
Effects of the positions of scintillation detectors with fast scintillators and photomultiplier tubes on TOF-PET performance
No full textThe objective of this study is to improve the time resolution value of a coincidence spectrometer used in a time-of-flight-positron emission tomography (TOF-PET) system. This spectrometer is used in medical imaging systems. the coincidence spectrometer is manufactured by using a BC420-type plastic scintillator and R1828-01-type photomultiplier tube, and the time resolution value of the manufactured spectrometer is determined. the accuracy of the experimental results is determined using the FLUKA Monte Carlo simulation program. Detectors are first manufactured in this program. Experimental and simulation results are compared and are found to be in good agreement. Optimal positions of the detectors are investigated to improve the coincidence time resolution of the spectrometer. Time resolution improvement of the optimal detector positions enables higher time-of-flight (TOF) gain and spatial resolution, leading to better image quality, reduction in patient doses and detection of small lesions.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [116F324]This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 116F324
Investigation of the Operation of a Fast Photomultiplier in a Scintillation Alpha-Particle Detector
No full textBu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.V ÖZET TARIMSAL İŞLETMECİLİK YAYIMI ve SÜT SIĞIRCILIĞI ÖRNEK OLAYI SARI, Mehmet AH Yüksek Lisans Tezi, Tarım Ekonomisi Bölümü Tez Yöneticisi: Prof. Dr. Erdoğan OKTAY Mart, 2000, 164 sayfa Bu tezde ülkemizde pratik olarak fazla uygulama alanı bulmayan tarımsal işletmecilik yayımı ile ilgili bir örnek çalışma yapılmıştır. Araştırma İzmir ili Bayındır ilçesi Hasköy köyünde bulunan süt sığırcılığı üretim faaliyetinin önemli olduğu işletmelerle yapılmıştır. Çalışmada incelenen işletmelerin mevcut durumları ortaya konmuş ve geliştirilmiş bütçeleme tekniği kullanılarak işletmeler planlanmıştır. İşletmecilere üç değişik plan sunularak seçim yapmaları istenmiştir. Seçim ve diğer aşamalardaki gözlemlere dayanılarak çalışmanın sonuçlan verilmiş ve ülkemizde tarımsal işletmecilik yayımı faaliyetlerinin uygulanması sırasında karşılaşılabilecek sorunlar ve çözüm önerileri sunularak çalışma tamamlanmıştır. Araştırmada yapılan planlama sonucunda işletmecinin yapmayı düşündüğü plan değişiklikleri sonucunda net tarımsal gelir ortalama %13,40 artarken, yayımcının yapmış olduğu planlarda bu oran %33,44 oranında gerçekleşmiştir.VI Araştırma sonucunda planların seçiminde ekolojik faktörler, gelecek ile ilgili beklentiler, yayjmcıya olan inanç, kendîndenlik olgusu gibi faktörlerin etkili olduğu saptanmıştır. Tarımsal işletmecilik yayımı çalışmalarının yapılmasına engel teşkil edebilecek sorunlar da makro ve mikro sorunlar olarak gruplandınlmıştır. Makro sorunlar yayımcının ve yayım kuruluşunun tek başına aşamayacağı tarım politikasının genel sorunları olmakla birlikte mikro sorunlar yayımcının kendisi ile ilgili olan ve yayım metotlarının kullanılması aşamasında ortaya çıkabilecek sorunlar olarak göze çarpmaktadır. Araştırmada sonuç olarak Türkiye'de tarımsal işletmecilik yayımı faaliyetlerinin gerçekleştirilebilmesi için özellikle makro sorunların ortadan kaldırılması gerektiği ve bu çalışmalar için uygun kurumsal örgütlenmenin sağlanmasının şart olduğu belirlenmiştir. Anahtar Sözcükler: Tarım işletmeciliği, yayım, planlamaVII ABSTRACT FARM MANAGEMENT EXTENSION AND A CASE STUDY m DAIRY PRODUCTION SARI, Mehmet Ali MSc in Agricultural Economics Supervisor: Prof. Dr, Erdoğan OKTAY March 2000, 164 pages In this thesis, a research was made about farm management extension that couldn't find applying area in Turkey. The research was made with farms that dairy production is important İn Hasköy village in Bayındır County of İzmir province. Firstly, present conditions of observed farms were defined and by using forward planning method, three plans were prepared. Those plans were presented and wanted to be selected by farmers. According to the observation of selection and the other stages, the results were given and problems that may be encountered while applying farm management extension were defined and by giving possible solutions, the study was concluded. With plans made by farmers thoughts, net farm income was increased % 13,40 portion, plans made by extension worker increased net farm income in percentage of 33,44 portion. It has been found that several factors effects selection of plans such as ecological factors,VIII expectations about future, belief towards to extension worker and subjectivity fact. Problems which may be encountered in applying farm management extension were grouped in two category as macro and micro problems. Macro problems are which extension workers and extension organization cannot deal with. Those problems also are the same as general agricultural policy's problems. Micro problems are which is related to extension workers and extension organization. Usually those problems occurs while applying extension methods. As a result, To realize farm management extension studies in wide area, especially macro problems must be solved and policy makers provide strong institutional structure. Keywords; Farm management, extension, advisory work, planning
A Different Method to Determine the Gamma-ray Linear Attenuation Coefficient
No full textAbstract: Gamma-ray linear attenuation coefficient values of Pb, Fe, and Al absorber materials were investigated. A fast coincidence timing measurement spectrometer was used for this purpose differently from other traditional spectrometers. A solid point 22Na positron source was utilized for the annihilation radiations. Obtained results were compared with those of XCOM program and literature values. © 2021, Pleiades Publishing, Ltd.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 116F324This work was supported by TUBITAK, the Scientific and Technological Research Council of TURKEY under project number 116F324
A theoretical way to determine gamma-ray mass attenuation coefficients of materials
No full textThe gamma-ray mass attenuation coefficients of various absorber materials such as Ag, Al, Au, Bakelite, Cu, Fe, Pb, Plexiglas, Si, Sn, water, and Zn were determined theoretically at different gamma-ray energies and different absorber thicknesses in order to investigate how the number of gamma photons and their energies affect the calculation of mass attenuation coefficients of the absorbers since no study such a comprehensive work here was encountered. For this purpose, the FLUKA Monte Carlo (MC) and XCOM programs were used. Calculated coefficients were compared to the literature values and found to agree well with them. The FLUKA MC program was successful in the calculation of gamma-ray mass attenuation coefficients of materials as was XCOM. The coefficient results were affected by the number of incident gamma photons in the calculation, and a high incident photon number was suggested
A Method to Improve Gamma Energy Resolution of BC-420 Type Organic Scintillation Detector
No full textCurrently, plastic (organic) scintillators are using in new type positron emission tomography (PET) devices such as J-PET. But, these type scintillators have low gamma energy detection performance. Therefore, an experimental method was proposed to improve gamma ray energy resolution of an organic scintillation detector composed of a BC-420 type crystal. To do this, a timing spectrometer using constant fraction discrimination method was used. Gamma rays from a Cs-137 radioactive source were first detected directly then through the timing method, and the obtained results were compared. The results showed that used method is considerably successful in increasing the energy resolution of this type detector. So, it is believe that the J-PET detection performance will be able to enhance if the proposed method can be used in its electronics.Scientific and Technological Research Council of TURKEY [121F012]This work was supported by The Scientific and Technological Research Council of TURKEY under project no. 121F012
An Application of Timing Measurement
No full textSince beta spectra contain beta particles in all energy value from zero to maximum, it is difficult to detect the low-energy beta particles due to the electronic noise concealing their signals. In other words, the low-energy beta spectrum mostly remains under the noise spectrum. For this reason, an experimental method was proposed to select the original beta particle signals from the chosen electronic noise band in the low-energy part of the Tl-204 beta spectrum by means of constant fraction timing discrimination method. The results showed that the proposed method was enough successful to select the beta signals from within the noise signals. It is concluded that the used method here can distinguish not only the noise signals but also the different type of particle signals such as background from the original source particle signals, leading to enhance the detection performance.Scientific and Technological Research Council of TURKEY [121F012]This work was supported by The Scientific and Technological Research Council of TURKEY under project no. 121F012
