Eduardo G. Yukihara

Eduardo G. Yukihara
Paul Scherrer Institut | PSI · Department of Radiation Safety and Security

Ph. D. in Physics

About

190
Publications
24,446
Reads
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4,327
Citations
Introduction
My research focus on the use and development of luminescence materials and techniques (particularly thermally and optically stimulated luminescence) to practical problems in radiation dosimetry (including medical physics and personal monitoring) and temperature sensing.
Additional affiliations
June 2016 - May 2018
Oklahoma State University
Position
  • Professor
May 2016 - present
Paul Scherrer Institut
Position
  • Head of Department
September 2014 - August 2015
German Cancer Research Center
Position
  • Researcher
Education
January 1996 - June 2001
Independent Researcher
Independent Researcher
Field of study
  • Physics
January 1991 - December 1995
Independent Researcher
Independent Researcher
Field of study
  • Physics

Publications

Publications (190)
Article
The goal of the present work is to propose and validate a numerical model for the calibration of clearance monitors, aimed at determining conversion factors between the measured count rates and the activity for non-standard radionuclides and geometries. For this, Monte Carlo simulations were carried out using the multipurpose code FLUKA in combinat...
Article
The objective of this paper is to provide an overview of the current status in neutron personal dosimetry based on poly allyl diglycol carbonate (PADC), also commonly known by the commercial name CR-39, to summarize the best practices in the field, and to point future research directions. An overview of the fundamentals of the technique is given, i...
Article
Full-text available
The quest for new materials for thermoluminescence (TL) and optically stimulated luminescence (OSL) dosimetry continues to be a central line of research in luminescence dosimetry, occupying many groups and investigators, and is the topic of many publications. Nevertheless, it has also been a research area with many pitfalls, slow advances in our un...
Article
Full-text available
The objective of this work is to assess the photon energy and angle response of the radiophotoluminescence (RPL) personal dosimetry system used at the Paul Scherrer Institute (PSI) in terms of the operational quantities for external radiation exposure personal dose, Hp, and personal absorbed dose in local skin, Dlocal skin, defined in the Report 95...
Article
Full-text available
The objective of this work is to simulate the spectral gamma-ray response of NaI(Tl) scintillation detectors for airborne gamma-ray spectrometry (AGRS) using the state-of-the-art multi-purpose Monte Carlo code FLUKA. The study is based on a commercial airborne gamma-ray spectrometry detector system with four individual NaI(Tl) scintillation crystal...
Article
Full-text available
The objective of this study was to improve the precision of linear energy transfer (LET) measurements using $$\text {Al}_2\text {O}_3\text {:C}$$ Al 2 O 3 :C optically stimulated luminescence detectors (OSLDs) in proton beams, and, with that, improve OSL dosimetry by correcting the readout for the LET-dependent ionization quenching. The OSLDs were...
Article
We describe newly found correlations between thermoluminescence (TL), pulsed optically stimulated luminescence (POSL), and phototransfer TL (PTTL) signals in Al2O3:C. A set of Al2O3:C samples were characterized for their TL and OSL curve shapes, as well as TL/POSL integrals and correlated with their PTTL behavior. POSL was used to separate the cont...
Article
The objective of this work is to apply a model that accounts for the presence of shallow traps to the analysis of pulsed optically stimulated luminescence (POSL) data, which is used to characterize the luminescence lifetime and thermal quenching of luminescent materials. In particular, we focus on the analysis of photon arrival time distribution (P...
Article
Luminescence dosimetry is the process of quantifying the absorbed dose of ionizing radiation using detectors that exhibit luminescence. The luminescence intensity scales with energy absorbed from the radiation field. Calibration enables conversion of the luminescence intensity to the quantity of interest, for example the absorbed dose, kerma and pe...
Article
Full-text available
The objective of this work is to evaluate the optically stimulated luminescence (OSL) lifetime dependence on different polycrystalline CaB6O10:Ln, Agx (Ln = Gd, Tb and Ce; x: % molar concentration) compounds. For the determination of the luminescence lifetimes, time-tagged time-resolved (TTTR) data of the OSL under pulsed stimulation were analyzed....
Article
The objective of this work is to demonstrate that MgB4O7:Ce,Li, a new optically stimulated luminescence (OSL) dosimetric material, shows improved response for proton therapy dosimetry, with less reduction in luminescence detector efficiency with the particle linear energy transfer (LET). MgB4O7:Ce,Li was synthesized and its luminescence efficiency...
Article
The objective of this study is to examine the possibility of using the thermoluminescence (TL) of polymer fibers containing ground calcium carbonate (CaCO3) mineral fillers as emergency dosimeters. Calcite, consisting mostly of CaCO3, is a TL material that exhibits two distinct TL peaks that can be exploited for dosimetry and is a naturally occurri...
Article
The objective of this work is to address the analysis of photon arrival time distributions (PATDs) obtained using the pulsed optically stimulated luminescence (POSL) technique in two particular situations: (a) when the interval between pulses is insufficient for the full decay of some of the luminescence components, and (b) in the presence of shall...
Article
Objective: The purpose of this study is to estimate the energy and angular distribution of secondary neutrons inside a phantom in hadron therapy, which will support decisions on detector choice and experimental setup design for in-phantom secondary neutron measurements. Approach: Dedicated Monte Carlo simulations were implemented, considering cl...
Article
Passive radiation detectors based on the optically stimulated luminescence of anion-defective aluminum-oxide doped with carbon (Al2O3:C) are commonly used for personal, environment and medical dosimetry. However, their luminescence efficiency in measuring a certain type of radiation is strongly affected by the pattern of energy deposition at the na...
Article
Full-text available
Self-developing radiochromic film is widely used in radiotherapy QA procedures. To compensate for typical film inhomogeneities, the triple channel analysis method is commonly used for photon-irradiated film. We investigated the applicability of this method for GafchromicTMEBT3 (Ashland) film irradiated with a clinically used carbon-ion beam. Calibr...
Article
Fluorescence Nuclear Track Detectors (FNTDs) are part of a new technology developed for particle detection and applicable to personal neutron dosimetry. The objective of this study is to simulate the FNTD fast neutron response to: (i) assess and understand the performance of the existing neutron dosimeter design (Landauer Inc.) and its associated s...
Article
Full-text available
Magnesium tetraborate, MgB4O7, is an attractive host material for dosimetry due to the two characteristics: its low effective atomic number (Zeff = 8.4) and high neutron capture cross-section of the ¹⁰B isotope. Particularly, Ce³⁺ and Li⁺ ions co-doped MgB4O7 has shown optically stimulated luminescence (OSL) signal comparable to that of Al2O3:C, wh...
Article
Full-text available
The response of Al2O3:C optically stimulated luminescence detectors (OSLDs) was investigated in a 250 MeV pencil proton beam. The OSLD response was mapped for a wide range of average dose rates up to 9000 Gy/s, corresponding to a ~150 kGy/s instantaneous dose rate in each pulse. Two setups for ultra-high dose rates (FLASH) experiments are presented...
Article
Full-text available
The well-known thermoluminescent material LiF:Mg,Cu,P (MCP) was previously shown to emit significant optically stimulated luminescence (OSL). In this paper, we investigate the rate of OSL recombination processes in MCP, expressed as effective lifetimes, using time-correlated single photon counting, in this context often referred to as time-resolved...
Article
Full-text available
Solid State Nuclear Track Detectors (SSNTD) have been used as passive dosimeters for many decades. Fast neutron detection is performed by detecting recoil protons generated in a hydrogenous material (neutron converter). The dose is estimated by multiplying the recoil protons track-spots density present on the detector surface by a calibration coeff...
Article
Thermoluminescence dosimetry (TLD) has a long history of applications in medicine. However, despite its versatility and sensitivity its use is anecdotally diminishing, at least in part due to the complexity and work intensity of a quality TLD service. The present paper explores the role of TLD in medicine using a common inquiry methodology (5W1H) w...
Article
If the first decade of the new millennium saw the establishment of a more solid foundation for the use of the Optically Stimulated Luminescence (OSL) in medical dosimetry, the second decade saw the technique take root and become more widely used in clinical studies. Recent publications report not only characterization and feasibility studies of the...
Article
Full-text available
The objective of this work was to perform an extensive side-by-side comparison between a radiophotoluminescence (RPL) dosimetry system and thermoluminescent dosimeters (TLDs) or EDIS-1™ Environmental Direct Ion Storage Dosimeters during environmental and area monitoring. The measurement locations include points around and within the perimeter of th...
Article
Full-text available
The objective of this study was to investigate the energy and angle dependence of the RPL dosimetry system in use at the Paul Scherrer Institute (GBFJ-01 dosimeter, FGD 660 reader, and CDEC-Easy algorithm) for the operational dose quantity H*(10) and compare the results with the requirements from the Swiss dosimetry regulation. The energy response...
Article
The objective of this work is to demonstrate the potential application of Al2O3:C optically stimulated luminescence (OSL) films for 2D dosimetry in magnetic resonance guided radiotherapy (MRgRT), a modality which combines two dosimetric challenges: small field dosimetry and dosimetry in the presence of magnetic field. To achieve that, prototype Al2...
Article
This work presents the analysis of the images acquired by 3D scans of Fluorescence Nuclear Track Detector (FNTD)-based neutron dosimeters irradiated with fast neutrons. The objective is to demonstrate the feasibility of 3D track-spot detection and trajectories reconstruction of recoil protons, offering a robust δ-ray filtering, and investigate if t...
Article
Full-text available
The objective of this work is to demonstrate the feasibility of 2D dosimetry using optically stimulated luminescent (OSL) films based on MgB4O7:Ce, Li and to identify current limitations. A small quantity of test films was produced and read using a laser-scanning OSL reader after irradiation. The OSL luminescence and dosimetric properties were also...
Article
Although BeO ceramic (Thermalox® 995, Materion Co.) is today probably the most important alternative material to widely-used Al2O3:C in optically stimulated luminescence (OSL) dosimetry, the underlying OSL mechanism in BeO is not yet well-understood and contradictions in the thermoluminescence (TL) and OSL data interpretation remain. The recent dis...
Article
Thermoluminescent dosimeters (TLD) and optically stimulated luminescent dosimeters (OSLD) are practical, accurate, and precise tools for point dosimetry in medical physics applications. The charges of Task Group 191 were to detail the methodologies for practical and optimal luminescence dosimetry in a clinical setting. This includes: (1) to review...
Article
The objective of this study was to characterize the latest version of the electronic D-Shuttle dosimeter (Chiyoda Technol Corp., Tokyo, Japan) for potential use in dosimetry of members of the public. The investigations comprise: (a) reproducibility, batch homogeneity, dose linearity, dose rate and angle dependence, and radiation hardness using irra...
Article
The objective of this work was to investigate the thermoluminescence (TL) properties of lanthanide-doped CaSO4 synthesized by co-precipitation for particle temperature sensing applications. Desirable properties for temperature sensing include high TL intensity, stability of the TL signal against light exposure, low room temperature fading, UV emiss...
Article
The objective of this work was to characterize more in depth the newly discovered thermally transferred optically stimulated luminescence (TT-OSL) of BeO. The studies include a more detailed investigation of the pre-heating temperature and time required to induce the TT-OSL signal; the reproducibility, additivity, and stability of the TT-OSL signal...
Article
In this work we systematically investigated undoped and lanthanide(Ln)-doped MgO with diverse dopant combinations, MgO:Ce,Ln and MgO:Tb,Ln, where Ln=Eu, Yb, Tm, Sm, Dy, Nd, as well as the same combinations with an additional 3 mol% Li dopant. We characterized the thermoluminescence (TL), optically stimulated luminescence (OSL), radioluminescence (R...
Article
This work reports on the advances towards the development of a new optically stimulated luminescence (OSL) material based on MgB4O7:Ce,Li, which has high sensitivity to ionizing radiation, low effective atomic number (Zeff=8.2), and fast luminescence when doped with cerium (Ce3+ emission). MgB4O7 samples doped with 0.3 mol% Ce and 10 mol% Li were s...
Article
Full-text available
Photoluminescence (PL), thermoluminescence (TL) emission spectra and TL glow curves of barium yttrium fluoride (BaY2F8 – BaYF), undoped and doped with erbium (Er3+) or praseodymium (Pr3+) were measured to investigate the fundamental absorption (band gap – Eg), the nature of the trapping centers, as well as the electronic transitions of Ln3+ in BaYF...
Article
This work reports the observation of strong thermally transferred optically stimulated luminescence (TT-OSL) signal of BeO OSL ceramic detectors. If the detector is irradiated and the OSL signal is measured for a prolonged time (bleached), subsequent OSL measurements result in zero signal. If the same detector, however, is heated to temperatures in...
Article
The purpose of this work is to study the optically stimulated luminescence (OSL) and thermoluminescence (TL) properties of the Eu²⁺-doped KMgF3 (KMgF3:Eu). KMF powders were synthesized by a microwave – assisted hydrothermal method. The structural phase identification was performed by X-ray diffraction combined with Rietveld refinement. The TL and O...
Article
The objective of this work was to investigate the validity and accuracy of the initial rise method (IRM) in combination with step-annealing procedures for the analysis of realistically simulated thermoluminescence (TL) curves with strongly overlapped TL peaks. First-order TL curves associated with a variety of trapping center distributions (e.g. di...
Article
Thermoluminescence (TL) has traditionally been used to estimate the depth of trapping centers in luminescence materials and explain the isothermal decay in the case of synthetic dosimeters and natural materials used in luminescence dating. Nevertheless, new fields of application of TL and optically stimulated luminescence (OSL) materials, namely pa...
Article
The objective of this study was to compare poly-allyl diglycol carbonate (PADC) track detectors from different suppliers for linear energy transfer (LET) spectrometry and neutron dosimetry. PADCs are commonly used for passive personal neutron dosimetry, where a common approach is to couple the PADC with a plastic radiator to generate secondary char...
Article
The objective of this work is to demonstrate the possibility of performing fast neutron dosimetry up to 5 Sv using optical absorbance of polyallyl diglycol carbonate (PADC) detectors, obtained through grey level analysis of PADC images acquired with a commercial track-counting dosimetry system, and estimate the uncertainties involved. PADCs were ir...
Article
The objective of this study was to compare a neutron dosimetry system based on polyallyl diglycol carbonate (PADC) detectors with a new system based on Al2O3:C,Mg fluorescence nuclear track detectors (FNTD). The irradiations, performed as part of an intercomparison organized by the Physikalisch-Technische Bundesanstalt (PTB), Germany, were on a PMM...
Article
An investigation of the luminescent properties of undoped and rare earth (RE) singly- and co-doped YF3 was carried out by means of radioluminescence (RL) and thermoluminescence (TL) measurements. Materials were obtained by ligand-free co-precipitation with Ce, Tm, Tb or Eu substituting for Y, followed by calcination in air at 500 °C for 1 h. RL mea...
Article
This work gives an overview of the performance of a laser-scanning 2D dosimetry system developed for Al2O3 optically stimulated luminescence dosimetric (OSLD) films, particularly for applications in radiotherapy using external beams. Al2O3:C and Al2O3:C,Mg OSLD films were irradiated using a 6 MV X-ray beam, a 221 MeV proton and 430 MeV/u ¹²C scanne...
Article
Full-text available
The natural radiation environment in Low Earth Orbit (LEO) differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR), as well as of protons and electrons trapped in the Earth’s radiation belts (Van Allen belts). Protons...
Conference Paper
The objective of this study was to analyze the applicability of optically stimulated luminescence detectors (OSLDs) for dosimetry in magnetic resonance (MR) guided radiation therapy devices with focus on dose dependence and angular dependence on the magnetic field strength. Precise detectors for dosimetry in high magnetic fields for such devices ar...
Article
The objective of this work was to develop a new optically stimulated luminescence (OSL) material for dosimetry applications that is tissue equivalent and has high sensitivity to ionizing radiation, fast luminescence lifetime, and intrinsic neutron sensitivity. To achieve this combination of properties, we started with a host material with low effec...
Article
Full-text available
While there are innumerable devices that measure temperature, the nonvolatile measurement of thermal history is far more difficult, particularly for sensors embedded in extreme environments such as fires and explosions. In this review, an extensive analysis is given of one such technology: thermoluminescent microparticles. These are transparent die...
Article
Full-text available
The radiation environment encountered in space differs in nature from that on Earth, consisting mostly of highly energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones present on Earth for occupational radiation workers. Since the beginning of the space era, the radiation exposure during space missions has been...
Article
This work evaluates the dosimetric properties of newly developed optically stimulated luminescence (OSL) films, fabricated with either Al2O3:C or Al2O3:C,Mg, using a prototype laser scanning reader, a developed image reconstruction algorithm, and a 6 MV therapeutic photon beam. Packages containing OSL films (Al2O3:C and Al2O3:C,Mg) and a radiochrom...
Article
The objective of this work was to develop an image reconstruction algorithm for 2D dosimetry using Al2O3:C and Al2O3:C,Mg optically stimulated luminescence (OSL) films imaged using a laser scanning system. The algorithm takes into account parameters associated with detector properties and the readout system. Pieces of Al2O3:C films (~8 mm × 8 mm ×...
Article
The objective of this work is to develop a methodology for precise optically stimulated luminescence (OSL) dosimetry using BeO chips and an automated research reader (Risø TL/OSL reader, Risø National Laboratory), documenting optimum detector preparation procedures, readout conditions, sensitivity, minimum detectable dose, and precision. We investi...
Article
Full-text available
The goal of this work was to investigate the relevant dosimetric and luminescent properties of MgO:Li 3%,Ce 0.03%,Sm 0.03%, a newly-developed, high sensitivity Optically Stimulated Luminescence (OSL) material of low effective atomic number (Z eff = 10.8) and potential interest for medical and personal dosimetry. We characterized the thermoluminesce...
Article
The present work describes the procedures and results from the first temperature measurements in closed chamber detonations obtained using the thermoluminescence (TL) of particles specifically developed for temperature sensing. Li2B4O7:Ag,Cu (LBO), MgB4O7:Dy,Li (MBO) and CaSO4:Ce,Tb (CSO) were tested separately in a total of 12 independent detonati...
Article
Full-text available
The objective of this study was to characterize the time-resolved (TR) optically stimulated luminescence (OSL) from Al2O3:C detectors and investigate methodologies to improve the accuracy of these detectors in ion beam therapy dosimetry, addressing the reduction in relative response to high linear energy transfer (LET) particles common to solid-sta...
Poster
Purpose: To develop a 2D dosimetry system based on the optically stimulated luminescence (OSL) of Al2O3:C films for medical applications. Methods: A 2D laser scanning OSL reader was built for readout of newly developed Al2O3:C films (Landauer Inc.). An image reconstruction algorithm was developed to correct for inherent effects introduced by reader...
Article
Purpose: The objective of this work is to test the premise that luminescence materials with less under-response to proton beams can be identified by testing their dose response to low-LET radiation. The goal is to develop new Optically Stimulated Luminescence (OSL) materials with improved response for proton therapy dosimetry. Methods: We first mea...
Poster
Purpose: To develop a precise 2D dose mapping technique based on the optically stimulated luminescence (OSL) from Al2O3 films for medical applications.
Article
In this work a systematic study of the thermoluminescence (TL) of lanthanide-doped MgB4O7 was carried out to elucidate the thermally stimulated and recombination processes in this material. MgB4O7 samples undoped or doped with lanthanides (Ln) were synthesized using solution combustion synthesis. Li, Na and K were investigated as co-dopants to incr...
Article
The objective of this work is to test three thermoluminescent (TL) materials, Li2B4O7:Cu,Ag (LBO), MgB4O7:Dy,Li (MBO) and CaSO4:Ce,Tb (CSO), as passive temperature sensors. Particles of these materials were subjected to two heating profiles: (a) a slow heating profile (2 h inside a muffle furnace) or (b) a fast heating profile (dropping them throug...
Article
With the aim of developing a new phosphor for temperature sensing, the effect of different annealing processes and co-dopants (Ag, In, Dy or Ti) on the TL properties of copper-doped Li2B4O7 synthesized by Solution Combustion Synthesis was investigated. Compared with slow annealing, fast annealing induces a high temperature peak (310 °C) in the TL c...
Article
The objective of this work is to characterize three thermoluminescent (TL) materials synthesized in our laboratory and identified as having properties suitable for temperature sensing, including bright TL emission, low fading at room temperature and lowl ight-induced fading(bleaching) of theTL signal.They are lithium borate doped with copper and s...