Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “LAB”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Reasons to read this book (hint: it’ll help your weapons research) Q and A with author highlights Lab’s collections, importance of early weapons work

Michael Bernardin’s retirement actually looks a little more like a second career. This one, though, as an author of books. Bernardin retired last year after 35 years as a nuclear physicist that culminated with his role as the Associate Lab Director for Weapons Physics. Since then, he’s continued accessing the collections of the National Security Research Center, which is the Lab’s classified library.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2021

Sights of summer from Lab’s earliest days digitization preserves images from 1940s, features early staff enjoying Los Alamos

Working at the Lab during World War II was serious business, but even these world-changing scientists and staff found time to play during the summer months. The National Security Research Center (NSRC), which is the Lab’s classified library and also houses unclassified artifacts from Los Alamos history, recently rescanned candid footage from two of contributors to the Manhattan Project.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2021

Physical Lab Security: Before and After World War II

Physical security during World War II was important to maintaining the secrecy of the Manhattan Project, the government’s wartime effort to create the atomic bomb. In a perceived race against Nazi Germany to do so, physicist J. Robert Oppenheimer, the Lab’s first director, and General Leslie Groves, head of the Manhattan Project, needed a secluded place to build the clandestine Lab.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2021

Chicago Pile-1 paved the way for nuclear science and a lab in Los Alamos First self-sustaining nuclear chain reaction was nearly 80 years ago

On a bitter-cold winter day, 43 scientists gathered at an abandoned squash court at the University of Chicago where they would ultimately enable a secret lab in Los Alamos to change the world just years later. It was December 2, 1942. The group, led by Italian physicist and Nobel laureate Enrico Fermi, stacked graphite bricks, piling 57 layers that totaled more than 770,000 pounds. Later named Chicago Pile-1, their goal was to create the world’s first self-sustaining, controlled nuclear chain reaction. Inside the approximately 20-feet-tall pile were smaller blocks of uranium and control rods that, when removed, would cause the reaction to go critical – meaning create a nuclear chain reaction. It was roughly $1 million worth of materials, equivalent to nearly $16 million today, and a concept that a nuclear chain reaction would allow the weaponization of the atom. “Its success would be the crucial proof needed to know it would be possible to create an atomic bomb,” said LANL Historian Roger Meade (C-NR). “This was the precursor to the Lab we have today, nearly 80 years later.”

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Characterization of Tri-lab β-Tin (Sn)

This report documents details of the microstructure and mechanical properties of -tin (Sn), that is used in the Tri-lab (Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), Sandia National Laboratories (SNL)) collaboration project on Multi-phase Tin Strength. We report microstructural features detailing the crystallographic texture and grain morphology of as-received -tin from electron back scatter diffraction (EBSD). Temperature and strain rate dependent mechanical behavior was investigated by multiple compression tests at temperatures of 200K to 400K and strain rates of 0.0001 /s to 100 /s. Tri-lab tin showed significant temperature and strain rate dependent strength with no significant plastic anisotropy. A sample to sample material variation was observed from duplicate compression tests and texture measurements. Compression data was used to calibrate model parameters for temperature and rate dependent strength models, Johnson-Cook (JC), Zerilli-Armstrong (ZA) and Preston-Tonks-Wallace (PTW) strength models.

36 MATERIALS SCIENCE↗
DOE OSTI2022

An April Fools’ Day read from Lab history Famed physicist Richard Feynman’s safecracking, cipher-creating sense of play

Richard Feynman was fresh out of Princeton University’s doctoral program when recruited to assist in the creation of the atomic bomb at Los Alamos. In 1943, Lab director J. Robert Oppenheimer wrote that the 24-year-old was, “by all odds the most brilliant young physicist here, and everyone knows this.” Feynman attempted to live and examine life in a state of play and, as such, it’s only fitting to take a look back at the Nobel Prize winning scientist’s years at the wartime Lab as April Fools’ Day approaches.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2022

Oppenheimer biographer tours Lab while movie is filmed locally

While a Hollywood movie crew filmed the Oppenheimer movie in Los Alamos these past few weeks, a special guest stopped by the Lab in between takes and chats with big-name actors. Director Thom Mason invited Kai Bird, co-author of American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, to LANL while Bird was in town. The film’s director, Christopher Nolan, wrote the screenplay based on Bird’s Pulitzer Prize-winning biography, published in 2005. Oppenheimer was a physicist and the Lab’s first director of its wartime mission to secretly create the atomic bombs and help end World War II.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2022

Lab Groups partner to change street sign; New spelling honors culture, revisits weapons legacy

This is a LANL Today article. It offers a brief historical overview of the Lab’s presence on Enewetak Atoll for weapons testing purposes. It explains the Lab’s efforts to change the spelling of Eniwetok Drive to Enewetak Drive to reflect the preferred spelling of residents of Enewetak Atoll. The purpose is historical and cultural education.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2016

Nucleon and Nuclear Structure Studies in Electroproduction with the CLAS Detector at Jefferson Lab

A diverse program for studying the structure of nucleons and nuclei is underway using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. A wealth of data has been obtained in inclusive, semi-inclusive, and exclusive electroproduction reactions using a variety of unpolarized and polarized beams and targets. The results include studies of excited nucleon states, measurements of nucleon, proton and neutron Form Factors (FFs), Parton Distribution Functions (PDFs), Transverse Momentum Distributions (TMDs), and Generalized Parton Distributions (GPDs), as well as Short Range Correlations (SRCs) in nuclei and Color Transparency phenomena. Jefferson Lab's electron accelerator, CEBAF, doubled its energy to 12~GeV and the upgrade of the experimental equipment is near completion in the experimental halls. The upgraded CLAS detector, CLAS12, enables execution of a broader physics program, with the main focus on uncovering the TMDs and GPDs using semi-inclusive and exclusive reactions in a new kinematic domain. In this talk, an overview of the CLAS electroproduction measurements with 6~GeV CEBAF and prospects of nucleon and nuclear structure studies with the 12~GeV machine and the CLAS12 detector will be discussed.

Stepanyan, Stepan↗
DOE OSTI2015

New CTEQ-Jefferson Lab (CJ) analysis of parton distributions

We present preliminary results of a new global QCD analysis of PDFs from the CTEQ-Jefferson Lab Collaboration (dubbed "CJ15"), which includes several new data sets and recent theoretical developments. In particular, we study the constraints from new D0 data on *W* boson asymmetries on the *d/u* PDF ratio at large *x*, and, indirectly, on the models of nuclear corrections in the deuteron. The analysis also considers for the first time the impact of Jefferson Lab data on the free neutron/deuteron structure function ratio at large *x*, and reanalyzes the light antiquark asymmetry in the proton from Drell-Yan data using more flexible parametrizations and nuclear corrections to deuterium cross sections. The results provide a new set of baseline PDFs which can be used to more reliably calibrate the effect of future data from the LHC.

Keppel, Cynthia↗
DOE OSTI2023

Did you know the Lab and its first director share a birthday month? A look back at Oppenheimer’s wartime legacy through historical items in our collections

Many birthdays ago, at only 38 years old and with no previous administrative experience, J. Robert Oppenheimer accepted responsibility for a national security mission of unprecedented scale. His charge, handed down by Manhattan Project director General Leslie R. Groves, was to lead a team of the world’s foremost scientific minds in developing the first atomic bomb. Under Oppenheimer’s leadership, a community of over 6,000 scientists, engineers, and other personnel living and working at the top-secret lab in Los Alamos completed their task in only 27 months, delivering the world’s first two atomic weapons to the U.S. military. In honor of what would have been Oppenheimer’s 119th birthday (on April 22), the National Security Research Center remembers his contributions as an administrator and scientist and the scope of his legacy as the first director of the Lab through items in our unclassified collections.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2015

New CTEQ-Jefferson Lab (CJ15) Analysis of Parton Distributions

We present the results of a new global QCD analysis of PDFs from the CTEQ-Jefferson Lab collaboration (dubbed "CJ15"), which includes several new data sets and recent theoretical developments. In particular, we study the constraints from new D0 data on W boson asymmetries on the d/u PDF ratio at large x, and, indirectly, on the models of nuclear corrections in the deuteron. The analysis also considers for the first time the impact of Jefferson Lab data on the free neutron/deuteron structure function ratio at large x, and reanalyzes the light antiquark asymmetry in the proton from Drell-Yan data using more flexible parametrizations and nuclear corrections to deuterium cross sections. The results provide a new set of baseline PDFs which can be used to more reliably calibrate the effects of future data from the LHC.

Melnitchouk, W.↗
DOE OSTI2022

The Jefferson Lab Eta Factory (JEF) experiment

The Jefferson Lab Eta Factory (JEF) experiment is an upcoming experiment designed to run in Hall D at Jefferson Lab using an upgraded GlueX spectrometer to study various decays of the ? meson. The GlueX spectrometer consists of a ?2 Tesla solenoid magnet housing a liquid hydrogen target and drift chambers used for tracking charged particles and an array of lead glass blocks (the Forward Calorimeter (FCAL)) downstream of the magnet for detecting neutral particles. The decays of the ? meson can be used to measure the light quark mass ratio via the ???+???0 channel and allow access to higher-order terms in Chiral Perturbation Theory via the ???0?? channel. The decays can also be used to constrain new charge-conjugation violating/parity conserving (CVPC) reactions and to search for signatures of dark matter. In particular, the ???0?? channel can be used to search for lepto-phobic dark vector (B) bosons in the reaction ??B? (B??0?) or dark scalar (S) bosons in the reaction ???0S (S???). Studying the rare radiative decay channel ???0?? requires replacing the 4×4×45 cm3 lead glass blocks in the inner region of the FCAL with 2×2×20 cm3 lead tungstate crystals, which will provide twice better position and energy resolution. This talk will describe the JEF physics program and the upgrade to the FCAL.

Taylor, Simon↗
DOE OSTI2020

Evaluation of a streaming readout solution for Jefferson Lab experiments

Jefferson Lab (JLab) operates the CEBAF accelerator that provides a high energy (up to 12 GeV) and high current (up to 150 µA) polarized electron beam for fixed target experiments. JLab's mission is to provide substantial progress in understanding the Quantum Chromo Dynamics (QCD), the current theory of the spectrum and the dynamics of hadronic matter. Given the broad scientific program a general-purpose detector, CLAS12, has been designed and constructed. Such a detector requires a sophisticated trigger and current experiments use an on-line FPGA-based system that relies upon custom firmware and electronics both of which are difficult reconfigure from one experiment to the next. To overcome these challenges transitioning to a streaming readout has been proposed since it would allow a more flexible, easier to debug, software trigger to be developed. To facilitate this JLab is gaining experience with streaming readout systems and is actively working to design and test a streaming data acquisition architecture. Significant work has already been done to make existing front-end electronics compatible with operation in streaming mode. Software-wise, much work remains to be done but an existing framework, TriDAS, which was developed for underwater neutrino telescopes can, in principle, be used with the existing JLab hardware. A test stand is already in place in the INDRA DAQ development lab at JLab. This paper will present the development of this TriDAS based test system and it?s operation in-beam using parts of the CLAS12 detector to evaluate streaming readout for a large general purpose detector.

Battaglieri, Marco↗
DOE OSTI2017

Overview of the Jefferson Lab 12 GeV Experimental Program in Halls A,B, and C

The 11 GeV beam energy available in experimental Halls A, B, and C as part of the Jefferson Lab 12 GeV Upgrade, combined with the new equipment in those halls will provide a rich and diverse physics program. This program includes inclusive measurements used to constrain polarized and unpolarized quark distributions in nucleons, exclusive reactions to access nucleon and meson form factors and GPDs, semi-inclusive measurements aimed at constraining TMDs, as well as measurements from nuclei to provide further insight into the origins of Short Range Correlations and the EMC Effect. The experimental equipment was designed with the above program in mind and the three halls provide complementary capabilities. Magnetic focusing spectrometers in Hall C (the new SHMS and existing HMS) will provide precision separated and unseparated cross section measurements and ratios. The new large acceptance CLAS12 spectrometer in Hall B enables measurements over broad regions of phase space. In Hall A, the new SBS spectrometer, used in conjunction with the existing HRS or Big Bite spectrometers will provide access to very large Q2 and allow for measurements requiring both high luminosity and large acceptance. This talk will give an overview of the upcoming experimental program in Halls A,B, and C, in particular highlighting synergies between the hall programs, which will allow Jefferson Lab to maximize the science output its 12 GeV program.

Gaskell, David↗
DOE OSTI2017

Low Energy Nuclear Physics Experiments at Jefferson Lab

Jefferson Lab houses a state-of-the-art 12 GeV accelerator (CEBAF) that may be used to probe nuclear structure. Not all of the experiments at Jefferson Lab are carried out at the GeV scale though. Experiments in the CEBAF injector and in the Low Energy Recirculation Facility (LERF) are capable of doing experiments at low center of mass energy with very high intensities. I will go over some examples of experiments that have been either carried out or have been proposed using these low energy electron sources. The LERF contains an Energy Recovery Linac (ERL) that allows some novel experiments due to the combination of low energy, high current, and thick targets. An example of this, an experiment looking for dark matter candidates, will be described in some detail.

Benson, Stephen↗
DOE OSTI2023

Attend debut of new film on the Lab’s first director

The NSRC’s much-anticipated documentary, Oppenheimer: Science, Mission, Legacy, will premiere for Lab staff later this summer at the NSSB auditorium, and then be made available online. Speakers at the premiere will include film creator and primary producer Dave Tietmeyer (Multimedia Services, CEA-MP), Senior Historian Alan Carr (WRS-NSCMS), and NSRC Director Brye Steeves (WRS-DO). The film was entirely produced by the NSRC and Laboratory staff and will commemorate former director J. Robert Oppenheimer and his endeavors. Much of the material and several scenes featured in the film are based on collections from the Manhattan Project era and interviews with today’s Lab staff and Oppenheimer experts.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2023

Jefferson Lab Positron Program

The Jefferson Lab Polarized Electrons for Polarized Positrons (PEPPo) experiment demonstrated that it is possible to make polarized positrons with the polarized electron beam at CEBAF. Jefferson Lab is now looking to develop a dedicated positron source that will be able to feed the CEBAF accelerator with polarized positrons and deliver up to 11 GeV positrons to the experimental halls. I will present the plans for this new source as well as present an overview of the scientific program that is planned with this new source.

Higinbotham, Douglas↗