PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.
This PDF file contains the Front Matter associated with SPIE Proceedings volume 7806, including the Title page, Copyright information, Table of Contents, and Conference Committee listing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Background: Molecular breast imaging (MBI) is a novel breast imaging technique that uses Cadmium Zinc
Telluride (CZT) gamma cameras to detect the uptake of Tc-99m sestamibi in breast tumors. Current
techniques employ an administered dose of 20-30 mCi Tc-99m, delivering an effective dose of 6.5-10 mSv
to the body. This is ~ 5-10 times that of mammography. The goal of this study was to reduce the radiation
dose by a factor of 5-10, while maintaining image quality. Methods: A total of 4 dose reduction schemes
were evaluated - a) optimized collimation, b) improved utilization of the energy spectrum below the
photopeak, c) adaptive geometric mean algorithm developed for combination of images from opposing
detectors, and d) non local means filtering (NLMF) for noise reduction and image enhancement. Validation
of the various schemes was performed using a breast phantom containing a variety of tumors and containing
activity matched to that observed in clinical studies. Results: Development of tungsten collimators with
holes matched to the CZT pixels yielded a 2.1-2.9 gain in system sensitivity. Improved utilization of the
energy spectra yielded a 1.5-2.0 gain in sensitivity. Development of a modified geometric mean algorithm
yielded a 1.4 reduction in image noise, while retaining contrast. Images of the breast phantom demonstrated
that a factor of 5 reduction in dose was achieved. Additional refinements to the NLMF should enable an
additional factor of 2 reduction in dose. Conclusion: Significant dose reduction in MBI to levels comparable
to mammography can be achieved while maintaining image quality.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Thallium bromide (TlBr) and related ternary compounds, TlBrI and TlBrCl, have been under development for room
temperature gamma ray spectroscopy due to several promising properties. Due to recent advances in material
processing, electron mobility-lifetime product of TlBr is close to Cd(Zn)Te's value which allowed us to fabricate large
working detectors. We were also able to fabricate and obtain spectroscopic results from TlBr Capacitive Frisch Grid
detector and orthogonal strip detectors. In this paper we report on our recent TlBr and related ternary detector results
and preliminary results from Cinnabar (HgS) detectors.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron
source location and identification. Real-time detection and identification is important for locating materials. These
materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms
of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons,
constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and
proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for
imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton
scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered
neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and
discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The
hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased
sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252
source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification
distances and times, and projected effective area for a fully populated instrument.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The ion photon emission microscope (IPEM), a new radiation effects microscope for the imaging of single event effects
from penetrating radiation, is being developed at Sandia National Laboratories and implemented on the 88" cyclotron at
Lawrence Berkeley National Laboratories. The microscope is designed to permit the direct correlation between the
locations of high-energy heavy-ion strikes and single event effects in microelectronic devices. The development of this
microscope has required the production of a robust optical system that is compatible with the ion beam lines, design and
assembly of a fast single photon sensitive measurement system to provide the necessary coincidence, and the
development and testing of many scintillating films. A wide range of scintillating material for application to the ion
photon emission microscope has been tested with few meeting the stringent radiation hardness, intensity, and photon
lifetime requirements. The initial results of these luminescence studies and the current operation of the ion photon
emission microscope will be presented. Finally, the planned development for future microscopes and ion luminescence
testing chambers will be discussed.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A2BLnX6 elpasolites (A, B: alkali; Ln: lanthanide; X: halogen), LaBr3 lanthanum bromide, and AX alkali halides are
three classes of the ionic compound crystals being explored for γ-ray detection applications. Elpasolites are attractive
because they can be optimized from combinations of four different elements. One design goal is to create cubic crystals
that have isotropic optical properties and can be grown into large crystals at lower costs. Unfortunately, many elpasolites
do not have cubic crystals and the experimental trial-and-error approach to find the cubic elpasolites has been prolonged
and inefficient. LaBr3 is attractive due to its established good scintillation properties. The problem is that this brittle
material is not only prone to fracture during services, but also difficult to grow into large crystals resulting in high
production cost. Unfortunately, it is not always clear how to strengthen LaBr3 due to the lack of understanding of its
fracture mechanisms. The problem with alkali halides is that their properties decay rapidly over time especially under
harsh environment. Here we describe our recent progress on the development of atomistic models that may begin to
enable the prediction of crystal structures and the study of fracture mechanisms of multi-element compounds.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Radiation therapy typically employs high energy photon beams because the low absorption coefficient at these energies
minimizes skin dose with a conventional, unfocused beam. At orthovoltage energies less than 150 keV, the maximum
dose for a single beam occurs very close to the skin surface. However a well-focused beam of low energy x rays can
provide much higher flux at the target depth while sparing dose to the skin. The measured focal spot size for the
polycapillary optic was 0.2 mm and was found to remain unchanged through 50 mm of phantom thickness. The
calculated depth-dose curve was found to peak several centimeters below the surface with 25-40 keV radiation.
Modeling indicates that the tumor dose would remain much higher than
the skin dose even after scanning to cover a 1 cm3 tumor.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
SALOME (an acronym for Small Angle Lab Operation Measuring Equipment) is a versatile,
energy-dispersive x-ray diffraction imaging (XDi) test-bed facility commissioned and supported by the
Transportation Security Laboratory, Atlantic City, USA. In work presented here, the Inverse Fan-beam (IFB)
topology has been realized on SALOME and used to investigate the liquids identification capability of x-ray
diffraction (XRD).
Liquids were investigated from four classes of materials of relevance to security screening of aircraft
passenger luggage; namely: dilute aqueous liquids; concentrated aqueous liquids; hydrocarbon fuels; and
oxidizers. A set of features associated with the Molecular Interference Function (MIF) were used to classify the
liquids. Within the limited scope of this investigation, XRD proved to have excellent capability for
discriminating liquids from one another; in particular, for isolating the threat materials without raising false
alarms from either household or innocuous substances. Consequences for XRD-based screening of air passenger
luggage are summarized.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Our laboratory has investigated the efficacy of a suite of color calibration and monitor profiling
packages which employ a variety of color measurement sensors. Each of the methods computes
gamma correction tables for the red, green and blue color channels of a monitor that attempt to: a)
match a desired luminance range and tone reproduction curve; and b) maintain a target neutral point
across the range of grey values.
All of the methods examined here produce International Color Consortium (ICC) profiles that
describe the color rendering capabilities of the monitor after calibration. Color profiles incorporate a
transfer matrix that establishes the relationship between RGB driving levels and the International
Commission on Illumination (CIE) XYZ (tristimulus) values of the resulting on-screen color; the
matrix is developed by displaying color patches of known RGB values on the monitor and
measuring the tristimulus values with a sensor. The number and chromatic distribution of color
patches varies across methods and is usually not under user control.
In this work we examine the effect of employing differing calibration and profiling methods on
rendition of color images. A series of color patches encoded in sRGB color space were presented on
the monitor using color-management software that utilized the ICC profile produced by each
method. The patches were displayed on the calibrated monitor and measured with a Minolta CS200
colorimeter. Differences in intended and achieved luminance and chromaticity were computed using
the CIE DE2000 color-difference metric, in which a value of ΔE = 1 is generally considered to be
approximately one just noticeable difference (JND) in color. We observed between one and 17
JND's for individual colors, depending on calibration method and target.
As an extension of this fundamental work1, we further improved our calibration method by defining
concrete calibration parameters for the display, using the NEC wide gamut puck, and making sure
that those calibration parameters did conform, with the help of a state of the art Spectroradiometer,
PR670. As a result of this addition of the PR670, and also an in-house developed method of
profiling and characterization, it appears that there was much improvement in ΔE, the color
difference.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
SALOME (an acronym for Small Angle Lab Operation Measuring Equipment) is a versatile, energy-dispersive
x-ray diffraction imaging (XDi) test-bed facility; commissioned, funded and supported by the Transportation
Security Laboratory, Atlantic City, USA. In work presented here, SALOME has been used to investigate the
photon collection efficiency of three beam topologies that have been proposed for Next-Generation XDi,
namely: Direct Fan-beam (DFB); Parallel Beam (PB); and Inverse Fan-beam (IFB).
The single channel replication unit for each of the three topologies was implemented on SALOME. The
apertures defining each topology were varied in width, influencing both the detector scatter signal and the
momentum resolution. A small powder graphite sample was used as reference object for these measurements, as
it provided simultaneous data on counting rate as well as peak resolution for the selected Bragg peak. The
photon collection efficiencies at constant momentum peak width for the DFB, PB and IFB topologies were
found to follow the trend (from lowest to highest, respectively) conjectured elsewhere in the scientific literature.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Polycrystalline Mn2+ doped (0.5 wt%) MgSO4 has been prepared by using recrystallization method. The defect
assisted thermally stimulated luminescence (TSL) properties of Mn2+ doped MgSO4 induced by X-rays, were studied
in the dose range of 0.25 to 1.0 Gy. The resultant glow curves show an intensive glow peak around 475 K accompanied by one shoulder at 428 K. Computerized glow curve deconvolution tool is used to evaluate the effective trapping parameters and suggests quasi-continuous distribution of traps in the range of 0.50-1.08 eV. An
important feature of this phosphor is its 'non-shifting Tm (peak temperature)' property when the sample is subjected
to various doses of X-irradiation. TSL sensitivity of pure MgSO4 phosphor is enhanced with the incorporation of
Mn2+ impurity. The TSL response of this sample as a function of absorbed dose up to 1.0 Gy suggests that it will be
also very suitable for detecting very small exposures of low energy X-rays and γ-rays.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Current spectroscopic detector crystals contain defects that prevent economic production of devices with sufficient
energy resolution and stopping power for radioisotope discrimination. This is especially acute for large monolithic
crystals due to increased defect opportunity. The proposed approach to cost reduction starts by combining stereoscopic
IR and ultrasound (UT) inspection coupled with segmentation and 3D mapping algorithms. A "smart dicing" system
uses "random-access" laser-based machining to obtain tiles free of major defects. Application specific grading matches
defect type to anticipated performance. Small pieces combined in a modular sensor pack instead of a monolith will
make the most efficient use of wafer area.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Despite the outstanding scintillation performance characteristics of CeBr3 and LaBr3:Ce, commercial availability and
application is limited due to the difficulties with crystal growth of large, crack-free single crystals of these fragile
materials. Aliovalent doping was employed to strengthen CeBr3 in an effort to ease crystal growth constraints and
improve ingot yields. Six divalent (Ca2+, Sr2+, Ba2+, Zn2+, Cd2+ and Pb2+) and two tetravalent cations (Zr4+ and Hf4+)
were investigated as dopants to strengthen CeBr3 without negatively impacting scintillation performance. Ingots
containing nominal concentrations of 500ppm and 1000ppm of each dopant were grown. Fluorimetry, preliminary
scintillation, and preliminary fracture toughness measurements are presented for these aliovalently-doped scintillators.
While Ca2+, Zn2+, Cd2+, and Hf4+ all exhibited little or no change in the peak fluorescence emission for 300nm
excitation, Sr2+, Ba2+, Pb2+, and Zr4+ exhibited varying degrees of red-shifting. As expected, Pb2+ had a drastic
detrimental effect on scintillation. Initial microindentation data indeed indicates a noticeable increase in the fracture
toughness of the doped crystals as compared to undoped CeBr3.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.