Lawrence Berkeley Research Articles

From the pocket accelerator to major scientific facilities

The concept of “major scientific facility” was put forward by Ernest Lawrence, who invented the first cyclotron in 1929. Before Lawrence, all scientific research in the entire world can be said as “small science”, which is characterized by the research carried out by individuals or in small size of groups. Since the 1930s, due to the high financial need to build larger accelerators, Lawrence realized that a major scientific research project needs to be completed by a team with people of different expertise. His concept of teamwork has become a tradition in their laboratory at Berkeley and continues to this day. Major scientific facilities can provide ultimate research methods for exploring unknowns, which may likely lead to scientific breakthroughs. Since then, a new trend has gradually emerged in the development of science and technology, that is, every major breakthrough obtained in research, and even a significant step forward, is largely inseparable from installations of large facilities. This is precisely the impetus for countries all over the world to build major scientific facilities with huge investment. The development status of large scientific facilities determines a country’s ability to make such breakthroughs in cutting-edge research, and thus determines the country’s scientific and technological competitiveness in the world. Through the implementation of the Manhattan Project during the Second World War, the United States was directly benefited from the fact that the remaining facilities at that time all became national laboratories after the war. Following Lawrence’s original concept about the teamwork with major scientific facilities, the present article briefly reviews the history and current status of several national laboratories in the United States, and points out that the national-laboratory model can indeed form a strong scientific development impetus and play an international leading role in scientific and technological fields. I take four US national laboratories as examples: The Lawrence-Berkeley National Laboratory, the Argonne National Laboratory, the Oak Ridge National Laboratory, and the Los Alamos National Laboratory, to show that the model, centered on large-scale facilities with the management guaranteed by effective national plans and capital investment, is worthy of in-depth study for reference. In recent years, China has strongly emphasized the importance in the development of scientific research bases and has built a number of key laboratories. It is pointed out that comparing with the standard of the world-leading laboratories, China still needs to narrow the gap in management and in operation.

Neutron Response of the EJ-254 Boron-Loaded Plastic Scintillator

Organic scintillators doped with capture agents provide a detectable signal for neutrons over a broad energy range. This work characterizes the fast and slow neutron response of EJ-254, an organic plastic scintillator with 5% natural boron loading by weight. For fast neutrons, the primary mechanism for light generation in organic scintillators is n-p elastic scattering. To study the fast neutron response, the proton light yield of EJ-254 was measured at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. Using a broad-spectrum neutron source and a double time-of-flight technique, the EJ-254 proton light yield was obtained over the energy range of approximately 270 keV to 4.5 MeV and determined to be in agreement with other plastic scintillators comprised of the same polymer base. To isolate the slow neutron response, an AmBe source with polyethylene moderator was made incident on the EJ-254 scintillator surrounded by an array of EJ-309 observation detectors. Events in the EJ-254 target coincident with the signature 477.6 keV $\gamma$ ray (resulting from deexcitation of the residual $^{7}$Li nucleus following boron neutron capture) were identified. Pulse shape discrimination was used to evaluate the temporal differences in the response of EJ-254 scintillation signals arising from $\gamma$-ray and fast/slow neutron interactions. Clear separation between $\gamma$-ray and fast neutrons signals was not achieved and the neutron capture feature was observed to overlap both the $\gamma$-ray and fast neutron bands. Taking into account the electron light nonproportionality, the neutron-capture light yield in EJ-254 was determined to be 89.4$\pm$1.1 keVee.

Enhanced Long Term Durability of Metal-Supported Solid Oxide Electrolysis Cells By Advanced Coatings

Metal-supported solid oxide electrolysis cells (MS-SOECs) with symmetric cell architecture were developed for high temperature electrolysis at Lawrence Berkeley National Laboratory (LBNL). The cell is comprised of a thin ceramic electrolyte and porous electrode backbones sandwiched between stainless steel metal supports. MS-SOECs offer a number of advantages over conventional all-ceramic SOECs due to their low-cost structural materials (e.g. stainless steel), mechanical ruggedness, excellent tolerance to redox cycling, and extremely fast start-up capability. The current density of MS-SOEC at 1.3 V and 50 vol% steam content is improved by optimizing microstructure of electrode backbone and procedure of catalyst infiltration. MS-SOEC with composite LSCF-SDC air electrode catalyst displays a degradation rate of 1.6%/100 h with current density of 0.33 A cm-2 at 700 °C in 1000 h test (Figure 1). Post-mortem analysis reveals that the degradation is caused by the primary modes of fuel electrode catalyst coarsening and Cr poisoning on air electrode catalyst, and secondary modes of metal support oxidation and local elemental accumulation of Ni. In an effort to suppress Cr migration thereby improving long term durability, advanced coatings, such as CoOx, NiFe2O4, (Co,Mn)3O4, etc., are applied to the cathode-side support by atomic layer deposition or electrodeposition. The impact of coating composition and deposition method will be reported.Figure 1. Durability of the cell with LSCF-SDC air electrode catalysts at constant current of 0.33 A cm-2 and 700 °C, with 50 vol% H2-50 vol% H2O. Figure 1

Diffraction efficiency of a small-period astronomical x-ray reflection grating fabricated using thermally activated selective topography equilibration

We have fabricated a blazed x-ray reflection grating with a period of 160 nm using thermally activated selective topography equilibration (TASTE) and electron-beam (ebeam) physical vapor evaporation. TASTE makes use of grayscale ebeam lithography to create three-dimensional (3-D) structures in resist, which can then be thermally reflown into a desired profile. A blazed grating profile can be fabricated by selectively reflowing a periodic staircase structure into a wedge. This was done for the first time at a grating period of 160 nm, 2.5 times smaller than previous x-ray gratings fabricated using TASTE. The grating was patterned over a 10 mm by 60 mm area in a 147-nm-thick layer of poly(methyl methacrylate) resist and coated with 5 nm of chromium and 15 nm of gold using ebeam evaporation. The diffraction efficiency of the grating was measured using beamline 6.3.2 at Lawrence Berkeley National Laboratory’s Advanced Light Source. The results show a total absolute diffraction efficiency ≳40 % at lower energies, with maximum single-order diffraction efficiency ranging from 20% to 40%. The total diffraction efficiency was ≳30 % across the measured bandpass of 180 to 1300 eV.

What’s love got to do with it? Understanding local cognitive and affective responses to wind power projects

Negative perceptions of renewable energy development can lead to protest, resulting in project delay or failure. Alternatively, good communication and sensitivity to community feelings are pathways to success. While literature referencing the social aspects of wind power siting have become widespread, analyses which include individuals’ affect or emotional dimensions are rarer. Appreciation for emotional as well as cognitive perceptions is crucial for adequate understanding of not just consumptive or productive aspects of energy, but entire systems. We use a US national cross-sectional data set of 1705 individuals who live within 8 km of a wind turbine collected in a research project led by Lawrence Berkeley National Lab in a random probability-based phone, mail, and online survey in 2016. We hypothesize that individuals who moved-in prior to commencement of project construction will differ markedly from those who move in afterwards in terms of the cognitive and affective aspects of their attitude formation, and in particular, that negative emotions will be distinct. Variables include emotions such as pride, anger, and annoyance, perceptions of fit with the landscape, descriptions of the turbines as industrial and whether they added to or detracted from the community. We find affect is the stronger driver of attitude, but not merely by negative emotions. When we include both cognitive and affective variables, individual emotions are generally more predictive of attitude for pre-construction neighbors and cognitive variables such as wind being an effective means of climate mitigation and perception of property value change are stronger post-construction.

Comparative scintillation performance of EJ-309, EJ-276, and a novel organic glass

An organic glass scintillator developed by Sandia National Laboratories was characterized in terms of its light output and pulse shape discrimination (PSD) properties and compared to commercial liquid (EJ-309) and plastic (EJ-276) organic scintillators. The electron light output was determined through relative comparison of the 137Cs Compton edge location. The proton light yield was measured using a double time-of-flight technique at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory. Using a tunable broad-spectrum neutron source and an array of pulse-shape-discriminating observation scintillators, a continuous measurement of the proton light yield was performed for EJ-309 (200 keV–3.2 MeV), EJ-276 (170 keV–4.9 MeV), and the organic glass (50 keV–20 MeV) . Finally, the PSD properties of the organic glass, EJ-309, and EJ-276 were evaluated using an AmBe source and compared via a figure-of-merit metric. The organic glass exhibited a higher electron light output than both EJ-309 and EJ-276. Its proton light yield and PSD performance were comparable to EJ-309 and superior to that of EJ-276. With these performance characteristics, the organic glass scintillator is well poised to replace current state-of-the-art PSD-capable scintillators in a range of fast neutron detection applications.

Back to the Future: Helium Ion Therapy 2020

Helium ions (4He) remained clinically unexploited worldwide since the shutdown of the clinical trials at the Lawrence Berkeley Laboratory (LBL) despite their favorable physical and biophysical characteristics. 4He afford minimal lateral scattering compared to protons, with a significantly reduced fragmentation tail compared to carbon ions and enhancement of bio-effects with relative biological effectiveness (RBE) values ranging between 1.3 and ∼3. Here, we outline milestones and on-going preparations for 4He clinical trials set for this year at our facility. Investigation of physical and biological phenomena of 4He was performed. Dosimetry was conducted in both homogenous and heterogenous (clinical-like) settings, verifying prediction of the first (non-clinical) 4He Monte Carlo (MC) and GPU-accelerated based treatment planning system (gTPS). Towards translation in patients, these systems are supporting development and integration of the first clinical treatment planning system. Additionally, in vitro, in vivo and in silico biological studies were carried out to establish robust prediction of biological effects for 4He. Prescription doses, fractionation schemes, tissue radio-sensitivity (α/βx) assignment, algorithm for effective dose calculation, and RBE model were selected for the upcoming clinical trials using 4He. In water and in anthropomorphic head phantoms, measurements yielded dose values within ∼2% against MC and gTPS predictions. For RBE modeling, measured RBE in vitro and in vivo indicates clinically relevant uncertainty of ±5-10% across different RBE model as a function of the various endpoints (dose, linear energy transfer and tissue type). Based on improved performance in the studied cell lines and tissues, as well as its accessibility in the literature, the modified microdosimetric kinetic model (mMKM) was selected as the clinical model for 4He RBE prediction. Through interdisciplinary collaboration between physicians, physicists and radiobiologists, we have addressed the prospective challenges and clinical decisions necessary for translating active scanning 4He to the clinic. Developed physical/biological models were successfully integrated in both research and commercial systems and validated against in vitro/in vivo experimental data. Together, these efforts mark an important step towards clinical translation 4He ion-beam therapy with state-of-the-art technologies.

The organization of production for Inka Polychrome pottery from Pachacamac, Peru

This study investigates the organization of production for Inka Polychrome pottery used at the Temple of the Sun, Pachacamac. Inka Polychrome pottery was critical to imperial strategies for managing state power in the provinces. It was highly standardized in appearance yet is known to have been produced at many locations throughout the empire by Inka and subject potters. Pachacamac was an important political and ideological location on the central coast that was transformed by the Inka after C.E. 1470 into a major imperial center. To evaluate the production and source of pottery at Pachacamac, a sample of 149 ceramics in local, Inka Polychrome, and Regional Inka styles were evaluated using neutron activation analysis to identify compositional groups. Attributes related to the production and decoration of these ceramic artifacts were recorded and statistically compared between groups. Compositional data from this analysis was also compared to compositional data from ceramics excavated from other South American sites and analyzed at the Lawrence Berkeley National Laboratory. Results found that multiple groups of potters at multiple places (some of which are local) produced this pottery, and small amounts of pottery are being imported.

Special Issue “Observations of Coupled Processes in Fractured Geological Media at Various Space and Time”

K.-B.M. acknowledges support from the Institute of Engineering Research, Seoul National University. J.R. acknowledges support from the U.S. Department of Energy to the Lawrence Berkeley National Laboratory under contract No. DE-AC02-05CH11231. V.V. acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme through the Starting Grant GEoREST, grant agreement No. 801809 (www.georest.eu).

An Adaptive Prediction Strategy with Clustering in Wireless Sensor Network

In Wireless Sensor Network, sensed data reflects two types of correlations of physical attributes: spatial and temporal. In this paper, a scheme named, Adaptive Prediction Strategy with ClusTering (APSCT) is proposed. In APSCT, a data-driven clustering and grey prediction model is used to exploit both the correlations. APSCT minimizes the transmission of messages in the network. However, the use of prediction includes additional computation overhead. There is a trade-off between prediction accuracy and energy consumption in computation and communication in wireless networks. This paper also gives an approach to calculate the upper and lower bound of the prediction interval which is used to evaluate different confidence levels and provides an energy-efficient sensor environment. Simulation is carried out on real-world data collected by Intel Berkeley Lab and results are compared with existing approaches.

Cats and llamas could offer a path to coronavirus therapies

Computation and experimentation also yield possible therapeutic compounds for COVID-19 [ABSTRACT FROM AUTHOR] Copyright of Physics Today is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission However, users may print, download, or email articles for individual use This abstract may be abridged No warranty is given about the accuracy of the copy Users should refer to the original published version of the material for the full abstract (Copyright applies to all Abstracts )

Advanced light source-Upgrade accumulator-ring gas bremsstrahlung production

Lawrence Berkeley National Laboratory is designing a new electron synchrotron for scientific research using synchrotron radiation. An upgrade of the Advanced Light Source (ALS) would position the nation to retain its international competitiveness in the soft X-ray sciences. The ALS is a 1.9 GeV storage ring operating at 500 mA of beam current. It is optimized to produce intense beams of soft X-rays, which offer spectroscopic contrast, nanometer-scale resolution, and broad temporal sensitivity. Upgrading the ALS storage ring from a triple-bend-achromat to a multibend-achromat (MBA) lattice design will provide a soft X-ray source that is up to 100–1,000 times brighter than today’s ALS and will provide a significantly higher fraction of coherent light in the soft X-ray region than is currently available at the ALS. The upgraded ALS will offer the highest coherent flux of any existing or planned storage-ring facility, worldwide, up to a photon energy of 3.5 keV. The addition of an accumulator ring that enables on-axis, swap-out, recovery, and exchange of bunch trains is required to achieve this coherence and brightness. Analysis of the radiation generated and shielding required by the addition of this new accelerator is presented in this paper.

Radioactive Beams in Particle Therapy: Past, Present, and Future.

Heavy ion therapy can deliver high doses with high precision. However, image guidance is needed to reduce range uncertainty. Radioactive ions are potentially ideal projectiles for radiotherapy because their decay can be used to visualize the beam. Positron-emitting ions that can be visualized with PET imaging were already studied for therapy application during the pilot therapy project at the Lawrence Berkeley Laboratory, and later within the EULIMA EU project, the GSI therapy trial in Germany, MEDICIS at CERN, and at HIMAC in Japan. The results show that radioactive ion beams provide a large improvement in image quality and signal-to-noise ratio compared to stable ions. The main hindrance toward a clinical use of radioactive ions is their challenging production and the low intensities of the beams. New research projects are ongoing in Europe and Japan to assess the advantages of radioactive ion beams for therapy, to develop new detectors, and to build sources of radioactive ions for medical synchrotrons.

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

Summary As the share of variable renewable energy (VRE) grows in the electric grid, so does the risk of curtailment. While energy storage and hydrogen production have been proposed as solutions to the curtailment problem, they often pose technological and economic challenges. Here, we analyze the potential of data center load migration for mitigating curtailment and greenhouse gas (GHG) emissions. Using historical hourly electricity generation, curtailment, and typical data center server utilization data, we simulate the effect of migrating data center workloads from the fossil-fuel-heavy PJM to the renewable-heavy CAISO. The results show that load migration within the existing data center capacity during the curtailment hours in CAISO has the potential to reduce 113–239 KtCO2e per year of GHG emissions and absorb up to 62% of the total curtailment with negative abatement costs in 2019. Our study demonstrates the overlooked role that data centers can play for VRE integration and GHG emissions mitigation.

A cantilevered liquid-nitrogen-cooled silicon mirror for the Advanced Light Source Upgrade.

This paper presents a novel cantilevered liquid-nitrogen-cooled silicon mirror design for the first optic in a new soft X-ray beamline that is being developed aspart of the Advanced Light Source Upgrade (ALS-U) (Lawrence Berkeley National Laboratory, USA). The beamline is optimized for photon energies between 400 and 1400 eV with full polarization control. Calculations indicate that, without correction, this design will achieve a Strehl ratio greater than 0.85 for the entire energy and polarization ranges of the beamline. With a correction achieved by moving the focus 7.5 mm upstream, the minimum Strehl ratio is 0.99. This design is currently the baseline plan for all new ALS-U insertion device beamlines.

Identifying DA Allocation by Minimizing the Overall Cost of Customer Minutes Interrupted

Smart grid activities are increasing the implementation of automated sectionalizing devices on distribution systems. Most methods for identifying the optimal distribution automation allocation (DAA) utilize general cost functions to account for the monetary impact of outages. Although these methods minimize lifetime reliability costs, they do not necessarily align with methods utilized by utility commissions and utility companies to restore power. Existing DAA approaches minimize strictly for outage, installation, and maintenance lifetime costs; however, during an outage a utility is more focused on minimizing “customer minutes interrupted” (CMI's). Most methods specifically ignore CMI's and assume utilities can address them within their generic cost function. The approach described within this manuscript identifies optimal DAA by minimizing the cost of CMI's after an outage. To align with accepted utility and commission practices for measuring the monetary impact of automated systems, the approach determines reliability costs by employing the “cost/CMI”. To account for cost variations between feeders, the approach applies the utility's expected/desired feeder values for SAIDI, CAIDI, and/or SAIFI to calculate avoided costs as defined by Berkeley National Laboratory's 2018 study. The method is easily employed with computational software. Evaluation and comparison of the approach is performed utilizing the Roy Billinton Test System.

Emerging Nanomaterials for Light‐Driven Reactions: Past, Present, and Future

Emerging Nanomaterials for Light‐Driven Reactions: Past, Present, and Future

Minute mecysmaucheniid spider triggers fastest trap-jaws

When Hannah Wood first encountered tiny mecysmaucheniid spiders scurrying through the leaf litter in Chile, she had no idea that some of the minute arachnids would have more in common with a family of ants – trap-jaw ants – that attack their victims with spring-loaded jaws. Instead of sitting enthroned in a web, the feisty spiders grasp their quarry in a vice-like grip with a pair of fierce-looking chelicerae – jaws tipped with fangs – which snap closed to ensnare their prey. However, some members of the family performed the manoeuvre so fast that it could not be powered by muscle alone. Knowing that trap-jaw ants depend on springy structures held open by a latch prior to slamming their jaws shut, Wood travelled to New Zealand in search of other members of the mecysmaucheniid family, to discover how the spiders bring their jaws crashing together.After sifting the leaf litter through a fine mesh to collect the 2–4 mm long spiders, Wood goaded the animals into clamping their jaws shut by prodding them with an eyelash attached to a pin as she filmed the chelicerae slam closed at speeds of up to 100,000 frames s−1. Focusing on two of the closest members of the family, Zearchaea spp. and Aotearoa magna, Wood realised that Zearchaea clamped their jaws shut at blistering speeds of up to 18.2 m s−1. ‘This is the fastest arachnid movement ever documented’, she says. In contrast, Aotearoa closed their jaws more sedately, only reaching average speeds of around 0.09 m s−1. Then, Wood calculated the power necessary to produce Zearchaea’s eye-watering accelerations and realised that the spiders would require a muscle that could produce 670,000 W kg−1 of power – which is completely impossible – to close their jaws in 0.07 ms, although Aotearoa jaw muscles should be more than capable of powering their slower closure.Knowing that Zearchaea must depend on a spring-loaded catapult to provide the enormous power required to clamp their jaws shut, Wood CT scanned the minute spider's heads with Dula Parkinson at the Lawrence Berkeley National Lab Advance Light Source synchrotron to reveal how the jaws of both species connected to the carapace through muscles and ligaments. The slower Aotearoa jaws were equipped with nine pairs of muscles – one pair to pull the jaws open while the remaining eight muscle pairs clamp them shut. Zearchaea, in contrast, seem to have done away with three of the pairs of closure muscles.Focusing on the muscles that lever the jaws open in both species, Wood noticed that they rotate the jaws upwards before opening them wide in preparation for an attack; but there the similarities ended. Although she could see that four of the pairs of Aotearoa muscles were required to squeeze the chelicerae together, Zearchaea jaws seem to be slammed shut by a powerful catapult mechanism. By building a 3D printed model of the spider's head, Wood realised that a pair of springy ligaments linking Zearchaea’s chelicerae to the carapace could store energy like a catapult when they are stretched as the jaws open, before being locked in place by a piece of the exoskeleton close to the jaw bases. Wood suspects that this latch is only released when muscles attached to the hinge linking the two chelicerae yank it back, allowing the stretched ligaments to recoil, slamming the jaws together.While Zearchaea’s spring-loaded jaws definitely earn them a place in the arachnid record book, Wood is also keen to understand why the close relatives evolved such different strategies in the relatively brief time since they last shared a common ancestor.

Photoionization features of the ground and excited levels of Cl II and benchmarking with experiment

This report presents i) various characteristic features in photoionization cross sections (σPI) of Cl II + hν → Cl III + e for many fine structure levels of Cl II, 392 in total with n ≤ 10 and l ≤ 9, ii) comparison of features with those observed in an experiment carried out at the Advanced Light Source at Lawrence Berkeley National Lab, and iii) partial photoionization cross sections of the ground level for ionization leaving the core ion in to various excited levels for applications in plasma modeling. The features correspond to resonant structures, the shape of the background, and their interference effect in σPI of this near neutral ion Cl II with 16 electrons. σPI for the 5 levels of the ground configuration 3s23p4(3P0,1,2, 1D2, 1S0) of Cl II show regions of narrow Rydberg resonances at and near threshold energies, and resonant structures at higher energies in contrast to typical smooth decrease in the background. Various other features in σPI of levels of excited equivalent electron states and broad Seaton resonances in single valence electron excited levels are illustrated with examples. Comparison of calculated σPI of the 15 lowest levels with the combined features of the measured photoionization spectrum shows excellent agreement by reproducing and thus identifying them to the levels that they belong to. The calculations were carried out in relativistic Breit-Pauli R-matrix (BPRM) method using a close coupling wave function expansion of 45 levels up to 4s of the core ion Cl III. These levels were optimized using a set of 12 configurations going up to orbital 5s, 3s23p3, 3s3p4, 3p5, 3s23p23d, 3s23p24s, 3s23p24p, 3s23p24d, 3s23p24f, 3s23p25s, 3s3p33d, 3s23p3d2, 3p43d producing 283 levels of Cl III. The autoionizing resonances are delineated with a fine energy mesh to observe the fine structure effects. The present results will provide high precision parameters for various applications involving this less studied ion.

Frequency Event Categorization in Power Distribution Systems Using Micro PMU Measurements

Frequency is an important metric for power stability. To enhance the situational awareness in power distribution systems, this paper proposes a data-driven approach that utilizes the data from micro phasor measurement units (μPMU) to categorize frequency events observed in distribution feeders. The proposed approach has three layers, each of which analyzes if a frequency event is propagated from the transmission system, formed inside a distribution feeder or falsely produced by instantaneous frequency (IF) estimation algorithms, respectively. In the first layer, the Granger causality is utilized to compare the causal relations from measurements across different locations to decide if an event is propagated from the transmission side. In the second layer, a trained sparse coding dictionary is utilized to unmix the physical causes of a frequency event. In the third layer, a moving z-score based event-pair detector is applied to identify if a frequency event is algorithm-induced. The proposed approach is tested using the μPMU measurements collected from Lawrence Berkeley National Laboratory (LBNL) and Riverside Public Utility (RPU).