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At least 739 records · Page 41

Colonie FUSRAP Site - Radioactive Dust Sampling of Residential and Commercial Properties - 16384

The Colonie Formerly Utilized Sites Remedial Action Program (FUSRAP) Site is located in the Town of Colonie, Albany County, New York. The U.S. Army Corps of Engineers (USACE) is currently addressing environmental contamination associated with the Site. The area surrounding the Site consists of residential and commercial properties, known as vicinity properties (VPs). Cleanup activities have been completed on many of these VPs under the FUSRAP to address depleted uranium contamination. Soil remediation activities have been substantially completed at the Colonie FUSRAP Site and its VPs under the FUSRAP. Recent studies performed by an independent party and under FUSRAP identified uranium within indoor dust in residencies and businesses in the immediate vicinity of the Site. The studies were limited to non-living areas such as basement window sills, garages, and attics. This paper discusses the indoor dust sampling and analysis, in support of the Remedial Investigation (RI) for the VPs, and presents sampling results. The indoor dust sample media presented many technical challenges regarding sampling design, data reduction, and data interpretation. In addition, because the RI is focused on numerous resident-owned, rental, and commercial properties, challenges where presented regarding right-of-entry to sample. Isotopic uranium ratios observed in the majority of the samples are indicative of the depleted uranium contaminant, even at trace levels. While the sampling and analysis methods were effective at identifying depleted uranium in the majority of the samples, preliminary property-specific risk assessment results do not indicate the presence of depleted uranium in sufficient concentrations to pose unacceptable risk to VP inhabitants. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Radioactive Decay Chain Truncation Rules for Emergency Response Radiological Assessments

A set of radionuclide - decay chain truncation rules have been developed for use in the Turbo FRMAC and Specialized Hazard Assessment Response Capability (SHARC) software programs used to support radiological emergency response activities . Following the proposed rules, the software will truncate a decay chain after it encounters a progeny radionuclide with a half - life greater than 5,000 years. An analysis of the projected dose from many parent and progeny radionuclides over a 50 - year time period yielded that a radionuclide half - life cutoff of 5,000 years will exclude a negligible dose. Implementing the truncation rules will reduce the time required for assessments and minimize computer hardware requ irements without having a significant detrimental effect on dose projections and emergency response decisions. It is noted that the truncation rules may not be suited for long - term ( greater than 50 year) environmental assessments.

07 ISOTOPE AND RADIATION SOURCES↗

Investigating Quantum Materials with Half-Polarized Diffraction and magnetic PDF analysis at the HB-2A Neutron Powder Diffractometer

Local magnetic ordering and anisotropy is often central to the emergent behavior and subsequent functional properties in quantum materials and beyond. Neutron powder diffraction provides a straightforward yet extremely powerful technique for quantitative measurements of microscopic magnetic properties. The HB-2A powder diffractometer located at the High Flux Isotope Reactor in ORNL is traditionally utilized for long-range magnetic structure determination. Recently these capabilities have been extended to include methods aimed at accessing local magnetism: Half- polarized neutron powder diffraction (pNPD) and magnetic pair distribution function (mPDF) analysis. These two distinct techniques are possible on HB-2A due to the versatility of the instrument’s reciprocal space coverage, resolution and novel ultra-low temperature multi-sample changers that operate down to dilution refrigerator temperatures. This provides unique capabilities not found on any powder diffraction instrument and is particularly well suited to investigations of magnetic quantum materials. The development and implementation of these techniques will be discussed with a series of science case examples ranging from geometric frustrated magnets to magnetic metal-organic frameworks. Data reduction and analysis tools will be presented that enable the extraction of the local site susceptibility tensor and local spin-spin correlations in real space. Finally, potential combinations of these techniques in the form of half-polarized magnetic pair distribution function (pmPDF) analysis will be considered. Looking forward, HB-2A is undergoing a detector upgrade that will be in the user program by 2026. This will offer an order of magnitude increase in count rates to further aid the development of these often low signal measurements and provide new scientific capabilities.

Neutron Scattering↗

HDR {sup 192}Ir source speed measurements using a high speed video camera

Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

07 ISOTOPE AND RADIATION SOURCES↗

Sensitivity Calculations for Systems with Polyethylene Reflector Materials Using CLUTCH

The SCALE 6.2.4 code package contains four sequences for calculating $k_{eff}$ sensitivity coefficients. Two of these sequences use deterministic transport solvers: a one-dimensional (1D) capability based on XSDRN, and a two-dimensional (2D) capability based on NEWT. These sequences are restricted to the multigroup (MG) treatment of neutron energy. The three-dimensional (3D) sequences use the KENO V.a or KENO-VI Monte Carlo transport codes and can be used to calculate sensitivity coefficients with either MG or continuous-energy (CE) transport. The 3D sensitivities are ultimately reported in an MG structure, regardless of the method used in the transport calculations. If desired, the sensitivity coefficients can be reported with very fine energy resolution from a CE calculation, but they are calculated only in the MG library structure in the MG mode. CE TSUNAMI methods are available in SCALE starting in SCALE version 6.2. Sensitivity coefficients were generated using the 3D sequences as part of the generation of the SCALE 6.2.2 Validation Report; difficulties encountered when using the CLUTCH method for thick, fissionable-material reflectors were discussed and investigated as documented in a previous paper. This paper discusses the difficulties encountered in generating accurate sensitivity coefficients using the CLUTCH technique for polyethylene reflectors for two fast spectrum benchmarks. Direct perturbation (DP) calculations were performed to confirm the accuracy of the total sensitivity coefficient for important isotopes with large sensitivities in the system. Discrepancies were detected for CLUTCH-calculated sensitivity coefficients in the reflector of a critical experiment with a radial polyethylene reflector. A simple polyethylene-reflected plutonium sphere was then used to further investigate the discrepancy. Calculations performed using the iterated fission probability (IFP) method generated accurate sensitivity coefficients in both cases. The results of this study emphasize the need to confirm CLUTCH sensitivity results with DP calculations. IFP calculations are generally less efficient but more reliable than CLUTCH calculations. Improvements to the CLUTCH methodology that retain the greater efficiency but address identified difficulties are therefore potentially useful to analysts.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Fully Robotic Hot Cell Crane for Target Hall Operations at Isotope Research Facility - 18329

There are many types of equipment used in high radiation environments, but the super-sized and high precision lifting requirements for an isotope research facility in the USA called for one of the largest fully robotic cranes in the US. The 20 Ton Remote Handling Bridge Crane provided by PaR Systems met many challenging requirements for accuracy, repeatability and unique lifting motions in the radiation-shielded target hall of this facility. This robotic system was designed to address four main issues. The first is that the crane needed to be operated remotely due to high radioactivity during the time when it is needed most. Second is that high precision is needed due to the complex fit of multiple heavy shielding blocks. Third problem is that automated routines and exclusion areas were needed due to the remote operation of the system around high capital cost equipment. Lastly is the survivability of the equipment due to the high radiation environment. The facility robotic crane is an overhead top running multiple girder hot cell bridge crane (hereafter referred to as the system). The system is intended to be used in either manually operated or automated operation under computer control. Under automated control, the system provides highly accurate motion control in three linear axes as well as hook rotation. Using motion control programming, this highly accurate system ensures safe, remote movement of in-cell components. The system was designed to be remotely operated by a technician from the remote handling control room in the facility. This is facilitated by computer control using the System Graphical User Interface with feedback from a facility supplied video system. It can also be operated using a wireless hand held controller. The system will be used to place sensitive components with high precision in locations that will be difficult to observe directly. In order to accomplish this, it is critical that the system be capable of moving its payload with minimal swing, and with high accuracy, repeatability and reliability. The system will be operating in an environment where it will be exposed to both high energy neutrons and gamma radiation. Under beam-off conditions, the target hall will be hands-on accessible to accommodate crane maintenance. The system was installed and tested in early 2017 in advance of the live operations of the facility. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Impact of Spontaneous Fission Neutron Emission Energy on Neutron Detector Response

A parametric study was simulated in MCNP to investigate the impact of spontaneous fission neutron energy on neutron detector response. A total of 880 configurations were simulated by varying 3 He pressure and polyethylene reflector thickness for 8 different isotopes. Results showed that deviations between the simulated isotopes become more prevalent at higher energies with 238 U showing the greatest deviation. It was also observed that configurations comparable to most detection setups, 10 atm and 6 - 8 cm polyethylene, were closer to the upper bound of deviations from a 252 Cf. 240 Pu, a common spontaneous fission source of interest, ranged from 2% - 3% within this space. This suggests that further investigation is required to determine exact correction factors when calibrating neutron detectors with a 252 Cf. Although demonstrated here for a 4π-detection system, future plans include simulating a more detailed model of the MC-15 detection setup to determine exact correction factors for future experiments.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

UCLA Translational Biomarker Development Program (UTBD)

The proposed UTBD program integrates the sciences of diagnostic nuclear medicine and (radio)chemistry with tumor biology and drug development. UTBD aims to translate new PET biomarkers for personalized medicine and to provide examples for the use of PET to determine pharmacokinetic (PK) and pharmacodynamic (PD) drug properties. The program builds on an existing partnership between the Ahmanson Translational Imaging Division (ATID) and the Crump Institute of Molecular Imaging (CIMI), the UCLA Department of Chemistry and the Division of Surgical Oncology. ATID provides the nuclear medicine training program, clinical and preclinical PET/CT scanners, biochemistry and biology labs for probe and drug development, radiochemistry labs, and two cyclotrons. CIMI provides DOE and NIH-funded training programs for radio-synthesis (START) and molecular imaging (SOMI). Other participating entities at UCLA are the Department of Chemistry and Biochemistry and the Division of Surgical Oncology. The first UTBD project focuses on deoxycytidine kinase, a rate-limiting enzyme in nucleotide metabolism, which is expressed in many cancers. Deoxycytidine kinase (dCK) positive tumors can be targeted uniquely by two distinct therapies: 1) nucleoside analog prodrugs such as gemcitabine (GEM) are activated by dCK to cytotoxic antimetabolites; 2) recently developed small molecule dCK inhibitors kill tumor cells by starving them of nucleotides required for DNA replication and repair. Since dCK-specific PET probes are now available, PET imaging of tumor dCK activity could improve the use of two different classes of drugs in a wide variety of cancers.

07 ISOTOPE AND RADIATION SOURCES↗

Integrated Molten Salt Reactor Modeling Capabilities in NEAMS Thermal Hydraulics Tools

The DOE neams program supports a full range of computational thermal fluids analysis capabilities and code developments for a broad range of advanced reactor concepts. The research and development approach under the thermal fluids technical area synergistically combines three length and time scales in a hierarchical multi-scale approach. To enable multi-scale thermal fluids capability using these codes, a key joint effort has been underway to develop an integrated system- and engineering-scale thermal fluids analysis capability, through integration of SAM and Pronghorn codes, both based on the MOOSE framework. This report summarizes recent advances in developing an integrated system- and engineering-scale modeling capability for the msr concept, which has gained significant interest in recent years. A consistent framework was established by coupling Pronghorn and SAM through the Saline interface, with thermophysical properties provided by the Molten Salt Thermal Property Database (MSTDB-TP). Further improvements were made to the coupling schemes and domain-overlapping strategies, enhancing the stability and robustness of multi-code simulations. Verification and validation efforts demonstrate the accuracy of this integration across a range of benchmark problems, including one-dimensional heated pipe flows, three-dimensional natural convection loops with evolving isotopic compositions, and \gls{msre} demonstration cases. Within Pronghorn, new capabilities were introduced to model corrosion and noble-metal plating phenomena, supported by an extended thermal-hydraulics framework and refined turbulence treatments. To capture two-phase flow behavior, a multiphase Euler–Euler model was implemented in Pronghorn, including advanced closure relations, high-resolution advection techniques, and capillary force reconstruction. Preliminary verification cases confirm the fidelity of the approach, while planned validation efforts target canonical multiphase benchmarks and application to msr components such as the msre pump bowl. Finally, updates to SAM’s msr mass transfer modeling were extended to consider noble gas migration into porous structures like graphite. The point kinetics model was updated to include reactivity feedback contributions from any defined species, such as xenon. The gas transport model was expanded for applicability to gas mixtures, bubble efflux phenomena, and species transport between liquid and gas phases. A selection of multi-scale Sherwood number correlations from MOSCATO/NekRS and multi-phase correlations from literature have been added for improved accuracy in calculating mass transfer coefficients. A companion effort on developing system-level redox corrosion has also been incorporated into SAM. Collectively, these enhancements strengthen the predictive capability of SAM and Pronghorn for simulating MSR thermal-hydraulics, corrosion, multiphase behavior, and fission-product transport, providing a more complete toolset for design, safety analysis, and licensing support of next-generation \gls{msr}s.

42 - ENGINEERING↗

DICER: A new instrument at LANSCE to constrain neutron capture rates on radionuclides

With very few exceptions, direct measurements of neutron capture rates on radionuclides have not been possible. A number of indirect methods have been pursued such as the surrogate method, the γ-ray strength function method, the Oslo method and the β-Oslo method. Substantial effort has been devoted to quantify the usually large systematic errors that accompany the results from these techniques. A new instrument has been developed at the Los Alamos Neutron Science Center (LANSCE) to provide more accurate data on several radionuclides relevant to nuclear criticality safety, radiochemical diagnostics, astrophysics, nuclear forensics and nuclear security, by measuring the transmission of neutrons through radioactive samples and studying resonance properties. The Device for Indirect Capture on Radionuclides (DICER) and associated radionuclide production at the Isotope Production Facility (IPF), both at LANSCE, as well radioactive sample fabrication, have been under development the last few years. A description of the new apparatus, data on a few mid-weight stable isotopes and efforts on radionuclide measurements will be presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Verification of the ENDF/B-VII.1 Based MC 2 -3 Library Rev.1

The MC 2 -3 code, developed by Argonne National Laboratory under the DOE-NE NEAMS program, is a multigroup cross section generation code for fast reactor applications. Last year, the ENDF/B-VII.0 (E70) MC 2 -3 library, which has been extensively used, verified, and validated over a long period, was intensively reverified and updated to support the commercial grade dedication (CGD) requirement of the TerraPower Natrium project. This year, the ENDF/B-VII.1 (E71) MC 2 -3 library, the preliminary version of which was generated several years ago, was regenerated and rigorously verified to support the Natrium project as well as the completion of verification of the E71 library. The E71 library was verified using the process developed during the verification of the E70 library, including comparisons of cross sections with the NJOY-generated cross sections, comparisons of the resolved resonance cross sections with those using the PEDNF library, and comparison of total cross sections with the sum of partial cross sections. Additional verifications were conducted to ensure that the benchmark problem solutions with the E71 library are reasonable compared to the corresponding Monte Carlo solutions. Furthermore, the E71 gamma library was generated, which includes data for prompt gamma, delayed gamma, and delayed beta as well as neutron and gamma heating. The gamma library was verified at the level of individual isotopes. The EBR-II core solutions from MC 2 -3/ DIF3D and MCNP were compared, demonstrating that those solutions in terms of k-effective and assembly powers were in good agreement.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Resolved resonance region evaluations of n+ 206,207,208 Pb for fast spectrum applications

Resolved resonance region evaluations of the major isotopes of natural lead, 206 Pb, 207 Pb, 208 Pb, have been per formed to support the development of Generation IV reactors. In this study, validation of nuclear data for lead fast reactors was performed with simulations of shielding benchmarks, integral critical benchmarks, and quasi-differential scattering measurements. Sensitivity analyses of these systems showed that elastic scattering reactions above 100 keV were the dominant reactions driving system performance. The resolved resonance regions (RRRs) of the lead isotopes extend past 100 keV, making the RRR an ideal starting point to evaluate lead cross sections. Since the R-matrix requires knowledge of bound, distant, and observed resonances, it was necessary to evaluate from 10 -5 eV up to the respective limit of the RRR. The 208 Pb RRR evaluation was extended to 1.5 MeV in order to obtain resonance parameters used to calculate new elastic scattering angular distributions up to 1.5 MeV. Resonance parameter uncertainties and covariance were generated using the R-matrix code SAMMY. The new RRR parameters show a direct improvement to the scattering kernel below 1.5 MeV which in turn greatly improves fast critical experiments over ENDF/B-VIII.0.

206Pb↗

Poster — Thur Eve — 38: Feasibility of a Table-Top Total Body Irradiation Technique using Robotic Couch Motion

Purpose: To develop and test the feasibility of a table-top implementation for total body irradiation (TBI) via robotic couch motion and coordinated monitor unit modulation on a standard C-arm linac geometry. Methods: To allow for collision free delivery and to maximize the effective field size, the couch was rotated to 270° IEC and dropped to 150 cm from the vertical radiation source. The robotic delivery was programmed using the TrueBeam STx Developer Mode using custom XML scripting. To assess the dosimetry of a sliding 30×20 cm{sup 2} field, irradiation on a solid water phantom of varying thickness was analyzed using EDR2 radiographic film and OSLDs. Beam modulation was achieved by dividing the couch path into multiple segments of varying dose rates and couch speeds in order to deliver 120 cGy to the midline. Results: The programmed irradiation in conjunction with coordinated couch motion was successfully delivered on a TrueBeam linac. When no beam modulation was employed, the dose difference between two different phantom sections was 17.0%. With simple beam modulation via changing dose rates and couch speeds, the desired prescription dose can be achieved at the centre of each phantom section within 1.9%. However, dose deviation at the junction was 9.2% due to the nonphysical change in the phantom thickness. Conclusions: The feasibility of robotic table-top TBI on a C-arm linac geometry was experimentally demonstrated. To achieve a more uniform dose distribution, inverse-planning allowing for a combination of dose rate modulation, jaw tracking and MLC motion is under investigation.

07 ISOTOPE AND RADIATION SOURCES↗

Shrub and sedge rhizosphere communities display distinct affinities toward exudates and soil organic matter degradation: a quantitative stable isotope probing analysis

Warming temperatures are accelerating permafrost thaw and changing tundra vegetation, where woody shrubs are displacing sedges. Shrubs, such as Betula nana, and sedges, such as Eriophorum vaginatum, exhibit distinct life strategies including unique root-associated, or rhizosphere microbial communities. As permafrost thaws it unlocks previously unavailable carbon and nutrient sources resulting in deeper roots and a translocation of rhizosphere communities. Because permafrost microbial communities contain lower diversity and biomass than rhizosphere communities, the coalescence of rhizosphere and permafrost microbial communities could alter soil organic matter (SOM) degradation rates and increase greenhouse gas emissions. To identify metabolic strategies across distinct rhizosphere and permafrost microbial communities we conducted an isotope tracing incubation experiment. We inoculated thawed permafrost with shrub and sedge rhizosphere communities while adding exudates or water daily and compared this to an uninoculated control. After 46 days, we spiked samples with 18O enriched water or 13C enriched exudates and measured isotope incorporation into microbial DNA with quantitative stable isotope probing (qSIP). Our results indicate that exudate additions had little effect on uninoculated permafrost communities but the addition of exudates and rhizosphere inoculants had a compounding effect on respiration rates. We found that soils inoculated with shrub rhizosphere communities contained a mixture of exudate and SOM degraders while soils inoculated with sedge rhizosphere communities contained mainly SOM degraders. Finally, we found that individual microbial taxa exhibited maximum growth rates under specific combinations of microbial inoculant communities and exudate addition treatments. Our results reveal that microbial niches are strongly influenced by substrate preferences and community context, and suggest that a reduction in sedges and an expansion of shrubs may provide a mechanism by which permafrost carbon losses are mitigated through corresponding shifts in microbial communities and their substrate preferences.

Schaefer, Sean R [Natural Resources and Earth Syst↗

High Radiation Environment Nuclear Fragment Separator Magnet (Final Report)

Dipole magnets with a field of 2 T are needed for the 30° bend in the Facility for Rare Isotope Beams (FRIB) fragment separator. This magnet will be subjected to extremely high radiation and heat loads from the high radiation. Superconducting coils for this magnet would allow low power operation but traditional NbTi and Nb3Sn superconductors are sensitive to quenches from beam loss and must operate near 4.5 K where the removal of thermal heat generated by beam loss is inefficient due to basic Carnot principles. High Temperature Superconductor (HTS) offers a unique solution for the magnets in the high radiation environment expected at FRIB. These conductors can operate at 40 K where heat removal is an order of magnitude more efficient than at 4.5 K. The curved separator dipoles subtend a large angular bend which introduces some complications in the winding of the coils. One approach would be to wind the coils with a curved section on the inner and outer radial segments (banana shaped). The inner radial segment would be wound with a negative curvature that would tend to unwind. An alternate approach would be to use a straight segment on the inner segment to avoid the negative curvature (D-shaped). In Phase I coils with a limited number of turns were successfully wound for both configurations described. These coils were tested at 77 K in liquid nitrogen. The Phase II program concentrated on the design, structural analysis, prototyping and test of the HTS curved dipole coils required for the high radiation environment of the FRIB fragment separator region. A thermal analysis was performed to simulate that the heat load can be removed. A test coil containing 500 m of HTS conductor was constructed to be tested at the 40 K operating temperature. The anticipated heat load was simulated with heater strips to demonstrate that the heat can be removed and that the coil can operate in a stable state.

99 GENERAL AND MISCELLANEOUS↗

Quality assurance for the clinical implementation of kilovoltage intrafraction monitoring for prostate cancer VMAT

Purpose: Kilovoltage intrafraction monitoring (KIM) is a real-time 3D tumor monitoring system for cancer radiotherapy. KIM uses the commonly available gantry-mounted x-ray imager as input, making this method potentially more widely available than dedicated real-time 3D tumor monitoring systems. KIM is being piloted in a clinical trial for prostate cancer patients treated with VMAT (NCT01742403). The purpose of this work was to develop clinical process and quality assurance (QA) practices for the clinical implementation of KIM. Methods: Informed by and adapting existing guideline documents from other real-time monitoring systems, KIM-specific QA practices were developed. The following five KIM-specific QA tests were included: (1) static localization accuracy, (2) dynamic localization accuracy, (3) treatment interruption accuracy, (4) latency measurement, and (5) clinical conditions accuracy. Tests (1)–(4) were performed using KIM to measure static and representative patient-derived prostate motion trajectories using a 3D programmable motion stage supporting an anthropomorphic phantom with implanted gold markers to represent the clinical treatment scenario. The threshold for system tolerable latency is <1 s. The tolerances for all other tests are that both the mean and standard deviation of the difference between the programmed trajectory and the measured data are <1 mm. The (5) clinical conditions accuracy test compared the KIM measured positions with those measured by kV/megavoltage (MV) triangulation from five treatment fractions acquired in a previous pilot study. Results: For the (1) static localization, (2) dynamic localization, and (3) treatment interruption accuracy tests, the mean and standard deviation of the difference are <1.0 mm. (4) The measured latency is 350 ms. (5) For the tests with previously acquired patient data, the mean and standard deviation of the difference between KIM and kV/MV triangulation are <1.0 mm. Conclusions: Clinical process and QA practices for the safe clinical implementation of KIM, a novel real-time monitoring system using commonly available equipment, have been developed and implemented for prostate cancer VMAT.

07 ISOTOPE AND RADIATION SOURCES↗

TH-CD-201-10: Highly Efficient Synchronized High-Speed Scintillation Camera System for Measuring Proton Range, SOBP and Dose Distributions in a 2D-Plane

Purpose: Proton therapy (PT) delivery is complex and extremely dynamic. Therefore, quality assurance testing is vital, but highly time-consuming. We have developed a High-Speed Scintillation-Camera-System (HS-SCS) for simultaneously measuring multiple beam characteristics. Methods: High-speed camera was placed in a light-tight housing and dual-layer neutron shield. HS-SCS is synchronized with a synchrocyclotron to capture individual proton-beam-pulses (PBPs) at ∼504 frames/sec. The PBPs from synchrocyclotron trigger the HS-SCS to open its shutter for programmed exposure-time. Light emissions within 30×30×5cm3 plastic-scintillator (BC-408) were captured by a CCD-camera as individual images revealing dose-deposition in a 2D-plane with a resolution of 0.7mm for range and SOBP measurements and 1.67mm for profiles. The CCD response as well as signal to noise ratio (SNR) was characterized for varying exposure times, gains for different light intensities using a TV-Optoliner system. Software tools were developed to analyze ∼5000 images to extract different beam parameters. Quenching correction-factors were established by comparing scintillation Bragg-Peaks with water scanned ionization-chamber measurements. Quenching corrected Bragg-peaks were integrated to ascertain proton-beam range (PBR), width of Spared-Out-Bragg-Peak (MOD) and distal.

07 ISOTOPE AND RADIATION SOURCES↗

Production of Medically Important Radionuclides 52 Mn and 90 Nb

Over the final reporting period of this project, we at MGH finalized our effort on Project 2: Production and Characterization of 90 Nb which, as per our previous report led us to an interesting application of mass spectrometry in radiometal chemistry. Overall, our research has developed parameters and procedures for delivering high 90 Nb for preclinical and translational applications by initializing the cyclotron targetry and separation chemistry for delivering 90 Nb in a chemical form suitable for subsequent development of 90 Nb-based PET radiotracers, and most recently we have published on the mass spectrometry applications described in the present report. We have been working with MSKCC (PI Jason Lewis) on the 90 Nb methodology and have had input from UAB (PI Suzy Lapi). An in-person meeting was held during the upcoming funding period with 2 PIs who are co-organizing the Radiochemistry Symposium (Lapi and Vasdev) and Program Director Dr. Ethan Balkin, during the ACS National Meeting in March 2018, and 2 PIs (Lewis and Vasdev) co presented in at the World Federation of Nuclear Medicine and Biology at a symposium sponsored by the Australian Nuclear Sciences and Technology Organisation, where they are both collaborating, in Melbourne, Australia in April 2018. Future projects and collaborations are under discussion with the Lapi lab to focus on new applications of 76 Br chemistry, and a new collaboration has already resulted with the Lewis lab on 18 F radiochemistry that employ iodonium ylide based precursors developed in the Vasdev lab, for clinical production of [ 18 F]MFBG. It is noteworthy that the PI has now relocated to the University of Toronto and has 2 cyclotrons (IBA Cyclone and Scanditronix MC-17) that will also be used to explore new 11 C-radiochemistry including [ 11 C]CO.

07 ISOTOPE AND RADIATION SOURCES↗