Philips, frazier bronson, ram venkataraman, brian m. Efficiency and resolution of hpge and naitl detectors. It was found that the resolution of the detector was directly proportional to the energy of gamma ray and its efficiency was exponentially proportional to the gamma ray energy. The structure of the naitl detector is illustrated in figure 3. The principle component in the scintillation detector is a tl doped sodium iodide crystal nai. Become familiar with some of the basic techniques used for measuring gamma rays with a sodium iodide nai detector. You will calibrate the detection system using radioactive sources available at the resource centre with gamma rays of known energy and then you will measure the energy of a gamma ray from an unknown source. Pdf isocs characterization of sodium iodide detectors for.
Gamma ray spectroscopy with a sodium iodide scintillation detector was chosen as the technique, by the easiness of use, high sensitivity and possibility of identification of an inadvertent. Semiconductor detectors the choice of a particular detector type for an application depends upon the xray or gamma energy range of interest and the. Gammaray interactions with matter 29 a much lower fraction of incident gamma radiation than does a similar thickness of aluminum or steel. The sodium iodide nai scintillator detector provides high efficiency.
In this experiment you will use both scintillation and semiconductor detectors to study. Naiti detector is the most widely detector use to detect gamma rays. Isocs characterization of sodium iodide detectors for gammaray spectrometry sasha a. Efficiency of hpge detector and nai tl detector as function of energy. Experiment 3 gamma ray spectroscopy using naitl equipment required purpose the purpose of this experiment is to acquaint the student with some of the basic techniques used for measuring gamma rays. How are the gamma rays produced, that are used in this experiment. When a gamma ray from a radioactive sample enters the crystal, some combination of three physical processes can occur. Why high purity germanium hpge radiation detection.
Sep 10, 2015 something else that we can use nai detectors for is identifying specific radionuclides by measuring the energy of each individual gamma that enters the crystal this process is called gamma spectroscopy, or can also be called multichannel analysis and the instrument set up for this purpose is called a gamma spectroscopy device, or a multi. Geometry correction in efficiency of a sodium iodide. Benchmark gamma spectroscopy measurements of uranium hexafluoride in aluminmum pipe with a sodium iodide detector showing 14 of 89 pages in this report. When these emissions are detected and analyzed with a spectroscopy system, a gammaray energy. This pair carries the gamma ray energy minus 2 m oc2.
Naitl crystals are widely used for radiation detection. Jan 10, 2020 in gamma ray spectroscopy, the energy of incident gamma rays is measured by a detector. Naiti detector is the m ost widely detector use to detect gam ma rays. Gamma ray spectroscopy and the scintillation detector data to verify the compton scattering theory is collected in this experiment using a gamma ray spectrometer that consists of a scintillation detector, high voltage supply, amplifier system, and a multichannel analyzer to measure the energy distribution of the detected gamma rays. Anglebw advanced gamma spectroscopy efficiency calibration software angleuw update from angleb32 version 2 or 3 to anglebw version 4 anglegw additional hard copy documentation for angle references references 1 and 2 are highly recommended to the interested reader. When a gamma ray energy from 10 kev to 5 mev enters a single crystal of sodium iodide activated with a thallium impurity about 0.
The most important interaction mechanisms are the photoelectric effect, the compton effect, and pair production. It is based on the use of a thalliumactivated sodium iodide detector. The equipment used in gamma spectroscopy includes an energy sensitive radiation detector, a pulse sorter multichannel analyzer, and associated amplifiers and data readout devices. Gamma ray spectroscopy using a naitl detector objectives.
This report presents an improved method for calibrating the sodium iodide nai detectors in the mobile in situ gamma spectroscopy systems used for scanning soils for radionuclides at the femald environmental management project femp. Components of a gamma spectroscopy system detector types the most common not the only detectors in gamma spectroscopy systems. By what means does the sodium iodide detector detect photons. High purity germanium and sodium iodide detector types. Gamma ray spectroscopy using naitl detector zafaran abdul fattah associate professor, deptt. It consists of a single crystal of thallium activated sodium iodide optically coupled to the photocathode of a photomultiplier tube. Relative probability of each of the three types of interactions as a function of energy. This technique has many applications, particularly in situations where rapid nondestructive analysis is required. This creates excited states in the crystal that decay by. Benchmark gamma spectroscopy measurements of uranium. A geometry correction file can also be generated for use in ortecs gammavision application so that the. Sodium iodide spectroscopy radiation detectors of all the available scintillators naitl is the most extensively used material. This light is then amplified and measured to produce an energy spectrum for radionuclide identification analysis. The written name of this type of detector is usually shortened to naitl.
Ph 3324 the scintillation detector and gamma ray spectroscopy. Gamma ray spectroscopy with nai ti and geli detectors. A typical diagram of a nai detector is shown below. The most common detectors include sodium iodide nai scintillation counters and highpurity germanium detectors. A labr detector is generally preferable to a nai detector. Pdf analysis of the relation between energy of gamma. Fast response with high sensitivity tells the operator that this is the right time and place to make a measurement. The gammaray spectrum will be obtained by using a sodium iodide nai scintillator detector.
The detector used in this experiment was thallium doped sodium iodide detector as shown in figure 1. Pdf isocs characterization of sodium iodide detectors. Pair production gamma ray energy binding a fraction of the gamma ray energy is transferred to the compton electron if gamma ray energy is 2 m oc2 electron rest mass 511 kev, a positronelectron can be formed in the strong coulomb field of a nucleus. These resolution values are expressed in absolute terms. The most common detectors include sodium iodide nai scintillation counter and high purity germanium detectors.
Dunlap, experimetal physics, oxford university press. To express the resolution in relative terms, the fwhm in ev or mev is divided by the energy of the gamma ray and usually shown as percentage. This pair carries the gammaray energy minus 2 m oc2. The improved method is faster, safer, and better at. The compton effect compton scattering and gamma ray. The energy dependence of efficiency and resolution of hpge and naitl detectors using gamma ray spectroscopy were investigated in this paper. By comparing the measured energy to the known energy of gamma rays produced by radioisotopes, the identity of the emitter can be determined. An introduction objective the primary objective of this experiment is to use an naitl detector, photomultiplier tube and multichannel analyzer software system to obtain the major primary gamma peaks of various elements, and to compare the acquired values with theoretical predictions. This experiment involves the use of radioactive sources and high voltages applied to the nai scintillation detector.
Efficiency and resolution of hpge and naitl detectors using. The naid unit is a nai detector specially designed for use in the measurement of uranium enrichment, and is used by the. Gamma ray spectroscopy 1 gamma ray spectroscopy in this experiment you will use a sodium iodide nai detector along with a multichannel analyzer mca to measure gamma ray energies from energy level transitions within the daughter nuclei of three lowlevel radioactive isotopes. Pdf gammarays spectroscopy by using a thallium activated. Read the section on pages 9293 of the attached reading about photons. Jan 01, 2010 benchmark gamma spectroscopy measurements of uranium hexafluoride in aluminmum pipe with a sodium iodide detector showing 14 of 89 pages in this report. Sigmaaldrich offers a number of sodium iodide products.
Hpge detectors have a 2030x improvement in resolution as compared to that of sodium iodide nai detectors. Pair production gammaray energy binding a fraction of the gammaray energy is transferred to the compton electron if gammaray energy is 2 m oc2 electron rest mass 511 kev, a positronelectron can be formed in the strong coulomb field of a nucleus. Learn more about ortecs 905 series naiti scintillation radiation detector and its capabilities. Uzair latif, imran younus department of physics lahore. A 2x2 inch sodium iodide nai detector will allow the user to identify the presence of cs7 at gamma spectroscopy measurements of uranium hexafluoride in aluminmum pipe with a sodium iodide detector showing 14 of 89 pages in this report. A hpge detector considered for this study was in continuous operation for the past 15 years in our laboratory. Snectra of cs7 and co60 using nal detector ljci spectra. Gamma spectroscopy detectors are passive materials that wait for a gamma interaction to occur in the detector volume. For example, a sodium iodide nai detector may have a fwhm of 9.
Gamma spectroscopy using naitl detector spectroscopy of any kind, deals with analysis of spectrum, i. The model 802 scintillation detector is a hermetically sealed assembly which includes a high resolution nai tl crystal, a photomultiplier tube, an internal magneticlight shield, an aluminum housing, and a 14pin connector. Ti scintillation counter california state university stanislaus, department offisics, turlock, ca 95380 5182014 in this paper we discuss the innerworkingsofthe thalliumactivatednat detector and its ability to resolve spectra. Sodium iodide spectroscopy radiation detectors north. N108 isocs characterization of sodium iodide detectors. Although field portable high purity germanium detectors are available, sodium iodide detectors are still often used for field applications. The gamma ray spectrum will be obtained by using a sodium iodide nai scintillator detector.
For onsite applications highresolution gamma spectrometry is mostly used only to quickly identify the material and obtain a rough idea about the isotopic composition of the material, i. Become familiar with some of the basic techniques used for measuring gamma rays with a sodium iodide nai detector that is thallium tl activated. Experiment 3 gammaray spectroscopy using naitl equipment required purpose the purpose of this experiment is to acquaint the student with some of the basic techniques used for measuring gamma rays. Gammaray spectroscopy is the quantitative study of the energy spectra of gammaray sources, such as in the nuclear industry, geochemical investigation, and astrophysics most radioactive sources produce gamma rays, which are of various energies and intensities. N energy resolution and efficiency where, the average value of full width at half maximum, fwhm, corresponds to the resolution of the high purity germanium hpge and sodium iodide nai tl detector. Advanced gamma spectroscopy efficiency calibration software. Gamma ray spectroscopy with naitl and hpge detectors. A 2x2 inch sodium iodide nai detector will allow the user to identify the presence of cs7 at gamma ray spectroscopy fig. Something else that we can use nai detectors for is identifying specific radionuclides by measuring the energy of each individual gamma that enters the crystal this process is called gamma spectroscopy, or can also be called multichannel analysis and the instrument set up for this purpose is called a gamma spectroscopy device, or a multi.
Gamma ray interactions with matter university of washington. Calibration of nai in situ gamma spectroscopy systems. Proportional counters have been used for spectroscopy of gamma rays and x rays whose energies are low enough a few tens of kev to interact with reasonable efficiency in the counter gas. When a gamma ray enters the detector, it interacts by causing ionization of the sodium iodide. The atoms of these type of detectors are easily excited by radiation and produce a spectrum that is characteristic of the chemical element present. The scintillation detector and gamma ray spectroscopy required background reading attached are several pages from an appendix on the web for tiplerllewellyn modern physics. Principles of gammaray spectroscopy and applications. Snectra of cs7 and co60 using nal detector ljci iviay i. Sodium iodide nai lanthanum bromide labr 21 lanthanum bromide labr high purity germanium hpge of these, the hpge is easily the best. Applied gammaray spectrometry covers real life application of the gammaray and the devices used in their experimental studies. Radseeker utilizes a detector system consisting of a sensitive inorganic scintillator, either sodium iodide nai or lanthanum bromide labr3, to convert gamma radiation to visible light.
This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the. Gamma ray spectroscopy 1 gamma ray spectroscopy theory. Of physics, faculty of education zingbar aden university doi. Gamma ray interactions with matter 29 a much lower fraction of incident gamma radiation than does a similar thickness of aluminum or steel. A hpge detector considered for this study was in continuous operation for the past 15 years in. This will briefly refresh your memory about the three ways that photons can lose. Gammaray spectroscopy using a naitl detector objectives. Isocs characterization of sodium iodide detectors for gamma ray spectrometry conference paper pdf available november 2004 with 82 reads how we measure reads. What is the probability that a 600 kev gamma ray undergoes photoelectric absorption in 1 cm of nai. The attenuation coefficient in equation 21 is called the linear attenuation coefficient. Gammarays spectroscopy by using a thallium activated sodium. Nai tl sodium iodide scintillation detectors berkeley. Gamma and xray detection introduction canberra industries. In addition, nai detectors, unlike hpge detectors, have been.
1678 1195 592 627 911 968 535 564 1605 40 1347 829 115 1319 932 467 1428 656 426 1173 783 1608 1486 85 1062 1080 1125 585 595 1204 1637 390 885 1508 728 213 903 1491 1010 1356 1442 466