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Optically stimulated luminescence dating - Wikipedia, the free encyclopedia Stimulating samples using infrared light causes luminescence, the intensity of which varies depending on the amount of radiation absorbed. Exposure to sunlight resets the luminescent signature and so the time period since the soil was buried by later sediments can be calculated. OSL is therefore most commonly used on prehistoric sites. en.wikipedia.org /wiki/Optically_stimulated_luminescence_dating   (221 words)

Optically stimulated luminescence - Wikipedia, the free encyclopedia In physics Optically stimulated luminescence or (OSL) is a method for measuring doses from ionizing radiation (commonly known as radioactive radiation). OSL is used in at least two entirely different applications: the dating of ancient materials (identical in purpose to the better known technique of radiocarbon dating), and as a method of radiation dosimetry which is the measurement of accumulated radiation dose in the tissues of health care, nuclear, research and other workers. While escaping the trap, and returning to a stable position or another trap, excess energy is emitted with a photon (light). en.wikipedia.org /wiki/Optically_Stimulated_Luminescence   (290 words)

Luminescence Dating The Dalhousie Thermally and Optically Stimulated Luminescence and ESR Laboratory When a laser light source is used to stimulate the release of electrons, the process is called optically stimulated luminescence. In 1985, they also developed optically stimulated luminescence dating techniques, which use laser light, to date sediments. id-archserve.ucsb.edu /Anth3/Courseware/Chronology/12_Luminescence.html   (621 words)

Luminescence Dating Optically stimulated Luminescence (OSL) where the material is stimulated with light source. Luminescence dating of sediment relies upon the fact that the geological luminescence signal of the sediment is reduced to a near-zero residual due to exposure to daylight during weathering and transport (see Aitken, 1985, 1998). Luminescence is a property by virtue of which any material emits light in response to some external stimulation and depending upon the stimulation this method is broadly has two derivatives: 1. www.uga.edu /osl/technique.html   (845 words)

Dating Exhibit The OSL (Optically Stimulated Luminescence) technique is similar to thermal dating. Optical dating is suitable for a variety of unheated sediments that are no older than 500,000 years. Since the OSL dating technique is sensitive to light the collection of the sample must be done carefully. www.mnsu.edu /emuseum/archaeology/dating/osl.html   (192 words)

Luminescence & Radiometric Dating Dig up the crystal, measure its luminescence (either optically or thermally stimulated), and you know the total dose. Luminescence is a phenomenon exhibited by many crystals, such as diamond, quartz, feldspars and calcite. The advantage of ESR is that, unlike luminescence, the electrons are not evicted from their traps, so the measurement can be repeated as desired on the same sample. www.tim-thompson.com /luminescence.html   (1399 words)

106972.041209&ELEMENT_SET=DECL OSL is used in integrating mode; that is, the OSL signal at any point in time is taken to be proportional to the net accumulated trapped charge up to that point. of the transient OSL signal during periodic stimulation to estimate the dose, the amplitude of the transient OSL signal being proportional to the dose with the constant of proportionality preferably being empirically determined. Thus, any given OSL signal is the net result of the total irradiation history of the sample to that point, and the number of previous stimulations (OSL readings) of the sample to that point. www.wipo.int /cgi-pct/guest/getbykey5?KEY=04/106972.041209&ELEMENT_SET=DECL   (4791 words)

Luminescence Laboratory, Department of Earth & Environmental Sciences, UIC A key advantage of OSL dating is that the luminescence of quartz and feldspar grains is reduced to a low definable level after a few minutes of sunlight exposures versus hours for the corresponding thermoluminescence response. This method applies additional doses (beta or gamma) to the natural luminescence on separate aliquots of the sample effectively building a dose response curve, simulating future dose and interpolating an equivalent dose to the solar reset level. There are currently two major analytical approaches that translate the time-stored luminescence to an equivalent dose, and thus to an age. www.uic.edu /labs/ldrl/osl.html   (368 words)

OPTICALLY STIMULATED LUMINESCENCE DATING USING SINGLE MINERAL GRAINS: POTENTIAL AND CHALLENGES Luminescence measurements of geological sediments allow the date of the last exposure of mineral grains to be calculated, and has been applied in the age range from a few decades to over 100 ka. Conventional luminescence measurements involve analysis of sub-samples consisting of many hundreds or thousands of mineral grains and assumes that all of the grains have been exposed to sufficient daylight at the time of deposition to reset the luminescence signal to a low level. Recent technological developments have made it easier to measure the luminescence signal from individual sand-sized (100-300 µm diameter) grains of quartz. gsa.confex.com /gsa/inqu/finalprogram/abstract_55765.htm   (472 words)

Radiation Measurements  Volume 33 The supralinear behaviour of the optically stimulated luminescence (OSL) signal is examined in an annealed quartz sample. Such investigations are important in luminescence dating and retrospective dosimetry, especially when the supralinearity intercept comprises a significant component of the paleodose in the sample. The sensitivity-uncorrected OSL growth curve of the annealed quartz sample 3-1/1 is observed to be supralinear in the dose range 0–5 Gy; it is then linear until about 20 Gy; and becomes sublinear beyond 20 Gy. www.prl.ernet.in /~library/banerjee_33_47_01.htm   (235 words)

89abstract.html Optically stimulated luminescence of some chips of a K-feldspar was measured as a function of the polarization angle of both the stimulating light and the emitted light. Optical transmission spectra were also measured and a polarization dependence found; it was, however, insufficient to account for the polarization effects observed in the optically stimulated luminescence. Crystal Anisotropy Effects in Optically Stimulated Luminescence of a K-feldspar. www.sfu.ca /physics/research/workarea/huntley/89abstract.html   (161 words)

Untitled Document While Optically Stimulated Luminescence Dating (OSL) is a well established and accurate dating technique for eolian and fluvial sediments, applications of OSL to glacio-fluvial deposits have remained troublesome. Overestimated luminescence ages of glacio-fluvial sediments have been attributed to partial bleaching of sediment in transport due to the attenuation of solar radiation through high suspended sediment concentrations throughout the water column. To investigate the effect of partial bleaching on luminescence dating and to gain an overall understanding of luminescence characteristics in glacio-fluvial sediments, modern (0-100a) West Greenland outwash plains were sampled. zephyr.unl.edu /OSL/Greenland.htm   (240 words)

Optically Stimulated Luminescence (OSL) Dating Optically Stimulated Luminescence (OSL) Dating is a Quaternary geologic age-dating technique used to determine the depositional age of sediments based on solid state properties of mineral grains rather than isotopic decay of constituent elements. OSL dating provides absolute (numeric) ages as opposed to relative chronologies and the ages are determined directly from the sediment grains themselves. Because OSL is not an isotopic technique, confounding issues such as variability in cosmogenic isotope production rates and incomplete geochemical system closure are not germane. ees5-www.lanl.gov /ees10/osl/BriefOSL.shtml   (410 words)

Introduction to Aberystwyth Luminescence Research Laboratory Luminescence dating is a Quaternary dating method used to determine the age of a sample. The luminescence dating laboratory in Aberystwyth is part of the Institute of Geography and Earth Sciences in the Within the Aberystwyth luminescence laboratory the majority of our luminescence measurements are made on automated systems built at Risø National Laboratory, Denmark. www.aber.ac.uk /~qecwww/luminescence/aberlum.htm   (277 words)

Luminescence Dating Optically Stimulated Luminescence (OSL) dating is a relatively new alternative approach to chronological problems. Luminescence expertise from both the Oxford and Sussex luminescence laboratories have been drawn on in the setting up and running of the SCIDR luminescence dating facility. The amount of luminescence emitted is proportional to accumulated dose and with the annual dose an age can be determined. www.shef.ac.uk /uni/academic/I-M/idry/lumindat.html   (302 words)

p9-3.doc A series of optical filters between the OSL film and photomultiplier tube reject the green stimulation light and pass the blue luminescence which has a peak wavelength of 420 nm. The amount of luminescence measured per unit dose that decreases with each measurement period depends on the optical energy imparted to the aluminum oxide film. The wavelength of the stimulation beam is 532 nm. www.srp-uk.org /srpcdrom/p9-3.doc   (1644 words)

Arcchaeometry Depending on the kind of stimulation one distinguishes ‘thermoluminescence’ and ‘optically stimulated luminescence’. The luminescence dating of sediments makes possible the reconstruction of landscape changes under the influence of prehistoric man. With the introduction of agriculture at the beginning of the Neolithic period the problem of soil erosion became potentially one of the major ecological threats. The intensity of the luminescence is related to the time interval (age) during which the mineral has been exposed to ionising radiation. www.mpi-hd.mpg.de /archaeometry/2002english.htm   (868 words)

The Optically ? Thermally Stimulated Phenomena Lab We have a Jobin-Yvon spectrofluormeter for TL, OSL and photoluminescence spectral measurements. Techniques in luminescence dating which are of interest include OSL and TL single aliqout and single grain procedures on quartz and feldspars. Both OSL and TL of a variety of materials are being examined for potential applications in space, where the complex radiation environment presents a challenge for conventional dosimetry methods and procedures. physics.okstate.edu /mckeever/lab/optical.htm   (757 words)

Luminescence dating When a mineral is stimulated by heat or light, Thermoluminescence (TL) or Optically Stimulated Luminescence (OSL) is emitted, respectively, and is a measure of the stored energy and therefore the total radiation exposure. The Luminescence dating facility was established in 1996 and is engaged in a range of Research, Service and Knowledge Transfer activities. Whilst recent technical developments have improved experimental errors on luminescence measurements to as little as ±1%, the precision of a luminescence age is ultimately restricted by systematic errors associated with equipment calibration. www.glos.ac.uk /schools/environment/facilities/envirolabs/geochronlabs/luminescence/index.cfm   (530 words)

SUERC Stimulation of the system, by heat in the case of thermoluminescence (TL), or by light in the case of photo-stimulated luminescence (PSL), or optically stimulated luminescence (OSL). Luminescence dating is based on quantifying both the radiation dose received by a sample since its zeroing event, and the dose rate which it has experienced during the accumulation period. Luminescence dating can be applied to the age range from present to approximately 500,000 years, thus spanning critical time-scales for human development and quaternary landscape formation. www.gla.ac.uk /centres/surrc/luminescence/dating.html   (865 words)

Recent Advances in Optically Stimulated Luminescence Dosimetry The Optically Stimulated Luminescence (OSL) technique has gained acceptance as a personal dosimetry system after the introduction of aluminum oxide (Al2O3) as the dosimetric material. This presentation will introduce the OSL and pulsed OSL technique and give a brief overview of some of the applications of OSL currently under development such as fiber dosimetry for radiotherapy and environmental monitoring, and space dosimetry. Special emphasis is given to space dosimetry and recently discovered ionization density dependence properties of the OSL of Al2O3. www.physics.isu.edu /colloquium/marianno04.html   (112 words)

Retrospective Radiation Dosimetry Using Optically Stimulated Luminescence in Dental Enamel: Possibilities for In vivo Dosimetry Since optical technology is amenable to miniaturization, a search for optically stimulated luminescence (OSL) in dental enamel was begun. Re-irradiation after heating caused a reappearance of the luminescence. OSL was also readily observed under IR photon stimulation in gamma irradiated samples of human dental enamel that had not been deproteinated. www.hps.org /newsandevents/meetings/midyear/abstract432.html   (364 words)

Colloquia The irradiation may be by x-rays, and rays, heavy ions, UV light, etc. In optically stimulated luminescence (OSL), the sample is excited in a similar way but the emission of light is stimulated by a different wavelength light. Following its exposure, the sample is heated (TL) or exposed to stimulating light (OSL), and the intensity of the emitted light is measured. Under favourable conditions, the intensity of the emitted light in TL and OSL is proportional to the radiation dose to which the sample has been exposed. www.phys.unsw.edu.au /SCHOOL_INFORMATION/COLLOQUIA/2001/august_23rd.html   (317 words)

Establishing the Optically Stimulated Luminescence (OSL) Facility OSL estimates are based on the time that has elapsed since buried sediment grains were last exposed to sunlight. We are now establishing an OSL dating facility at Los Alamos, and we will begin applying this technique to material transport problems in July 2001. When the grains are buried they begin to accumulate a trapped-electron population, caused by ionizing radiation from the decay of radionuclides in the deposit. ees5-www.lanl.gov /Publications/Articles/41establish_128.shtml   (411 words)

Single Grain Luminescence This is known as linearly modulated optically stimulated luminescence (LM-OSL). Time on the single grain reader is heavily used by members of the luminescence laboratory, but I am always interested to hear from people who have suggestions for novel or interesting applications of the equipment. A novel type of OSL proposed by Bulur (1996) is to linearly increase the intensity of the optical stimulation during the OSL measurement. users.aber.ac.uk /ggd/SGLL.htm   (1177 words)

UOS_Environmental & Safety_Radiation Safety_Dosimetry_How Does My Dosimeter Work Luxel's optically stimulated luminescence (OSL) dosimeter measures radiation exposure due to x-ray, beta, and gamma radiation through a thin layer of aluminum oxide and different filters. This luminescence is proportional to the amount of the radiation exposed to the dosimeter during use. The luminescence is proportional to the amount of radiation exposure during use. www.uos.harvard.edu /ehs/radsafety/dos_how.shtml   (183 words)

Geological Dating (1988) opened a new era of optical dating, showing that quartz and feldspar grains in sediments exhibit luminescence signals which are rapidly and fully zeroed by a few minutes of day light, thus avoiding the chief problem of TL dating. A good example of this is the use of OSL on potassium feldspar, because the radioactive potassium content insures a large internal dose to the grains. This led to widespread application of OSL techniques to windblown and waterlain sediments, which are of special importance to archaeological sites in the time range between 1 and 800 ka. www.science.mcmaster.ca /geo/research/age/dating.htm   (2431 words)

Begivenhedsarkiv In this work the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials is investigated. It is shown that OSL measurements of single grains of quartz extracted from poorly-bleached materials can provide useful information on radiation accident doses. The work focuses on identifying materials suitable for use in assessment of doses absorbed as a consequence of radiation accidents. www.fys.ku.dk /nbiweb/side19341.htm?foredragid=840   (170 words)

Dating Facilities - School of Earth & Environmental Sciences @ UOW Like Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) is a method of dating quartz by allowing the electrons within the quartz crystal to escape in the form of photons (light). Standard OSL technique is not appropriate in the area due to the high levels of feldspars and volcanic quartz, which display poor OSL emissions from the material in these areas. Rather than using heat to stimulate the quartz into releasing its electrons from their energy traps, OSL uses light as a source of stimulation. www.uow.edu.au /science/eesc/facilities/osl.html   (576 words)

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