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At least 19 records

Trinity 78th Anniversary: re-discovered and newly edited unclassified footage shows use of tanks to collect radioactive samples immediately after Trinity test (Rev. 1)

On July 16, 1945, at 5:29 a.m., a team of Los Alamos scientists successfully detonated the world’s first atomic bomb at a remote section of south-central New Mexico desert, then known as the Alamogordo Bombing Range. This full-scale test, dubbed “Trinity” by the Lab’s first Director J. Robert Oppenheimer, proved the viability of the implosion-type bomb known as The Gadget and ushered in the Atomic Age. Three weeks after Trinity, two Los-Alamos created atomic weapons – Little Boy and Fat Man – were released above Japan, helping to end World War II and changing the course of history forever.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Trinity by the Numbers: The Computing Effort that Made Trinity Possible

Utilizing rarely used source materials and identifying points of bias among more commonly used sources, this critical review provides a more complete representation of wartime Los Alamos computing operations and personnel, including the Laboratory’s typically underrepresented human computers and how they contributed to the success of the Trinity test. This paper also identifies how the Laboratory’s unusual wartime computing demands served as a formative experience among many Los Alamos personnel and consultants who contributed significantly to the development and use of mechanized computing at and beyond Los Alamos after the war.

79 ASTRONOMY AND ASTROPHYSICS↗

Trinity Supercomputer Now Fully Operational

Now one of the fastest supercomputers in the United States, the Trinity Supercomputer Phase II project was completed during the summer of 2017, and the computer became fully operational during an unclassified “open science” run. The computer has now transitioned to classified mode. The Trinity supercomputer is designed to provide increased computational capability for the NNSA Nuclear Security Enterprise in support of increasing geometric and physics fidelities in nuclear weapons simulation codes, while maintaining expectations for total time to solution. The capabilities of Trinity are required for supporting the NNSA Stockpile Stewardship program’s certification and assessments to ensure that the nation’s nuclear stockpile is safe, secure and effective. With an expected operational lifetime through 2020, Trinity is an approximately 41.5 petaflop (41.5 million billion calculations per second, peak performance) supercomputer based on the Cray XC40 architecture. It consists of 19,420 compute nodes utilizing two processor architectures, Intel Xeon Haswell and Intel Xeon Phi Knights Landing. It is a water-cooled system with a power requirement of about 10 megawatts. The Trinity project is managed and operated by Los Alamos National Laboratory and Sandia National Laboratories under the Alliance for Computing at Extreme Scale (ACES) partnership. The system is located at the Nicholas Metropolis Center for Modeling and Simulation at Los Alamos and covers approximately 5,200 square feet of floor space.

97 MATHEMATICS AND COMPUTING↗

FY17 CSSE L2 Milestone Report: Analyzing Power Usage Characteristics of Workloads Running on Trinity.

This report summarizes the work performed as part of a FY17 CSSE L2 milestone to in- vestigate the power usage behavior of ASC workloads running on the ATS-1 Trinity plat- form. Techniques were developed to instrument application code regions of interest using the Power API together with the Kokkos profiling interface and Caliper annotation library. Experiments were performed to understand the power usage behavior of mini-applications and the SNL/ATDM SPARC application running on ATS-1 Trinity Haswell and Knights Landing compute nodes. A taxonomy of power measurement approaches was identified and presented, providing a guide for application developers to follow. Controlled scaling study experiments were performed on up to 2048 nodes of Trinity along with smaller scale ex- periments on Trinity testbed systems. Additionally, power and energy system monitoring information from Trinity was collected and archived for post analysis of "in-the-wild" work- loads. Results were analyzed to assess the sensitivity of the workloads to ATS-1 compute node type (Haswell vs. Knights Landing), CPU frequency control, node-level power capping control, OpenMP configuration, Knights Landing on-package memory configuration, and algorithm/solver configuration. Overall, this milestone lays groundwork for addressing the long-term goal of determining how to best use and operate future ASC platforms to achieve the greatest benefit subject to a constrained power budget.

24 POWER TRANSMISSION AND DISTRIBUTION↗

CLARION2-TRINITY: A Compton-suppressed HPGe and GAGG:Ce-Si-Si array for absolute cross-section measurements with heavy ions

The design and performance of a new Compton-suppressed HPGe and charged-particle array, CLARION2-TRINITY, are described. The TRINITY charged-particle array is comprised of 64 Cerium-doped Gadolinium Aluminum Gallium Garnet (GAGG:Ce) crystals configured into five rings spanning 7–54 degrees, and two annular silicon detectors that can shadow or extend the angular coverage to backward angles with minimal $\gamma$-ray attenuation. GAGG:Ce is a non-hygroscopic, bright, and relatively fast scintillator with a light distribution well matched to SiPMs. Count rates up to 40 kHz per crystal are sustainable. Fundamental characteristics of GAGG:Ce are measured and presented, including light- and heavy-ion particle identification (PID) capability, pulse-height defects, radiation hardness, and emission spectra. The CLARION2 array consists of up to 16 Compton-suppressed HPGe Clover detectors (efficiency at 1 MeV) configured into four rings (eight HPGe crystal rings) using a non-Archimedean geometry that suppresses back-to-back coincident 511-keV gamma rays. The entire array is instrumented with 100- and 500-MHz (14 bit) waveform digitizers which enable triggerless operation, pulse-shape discrimination, fast timing, and pileup correction. Lastly, two examples of experimental data taken during the commissioning of the CLARION2-TRINITY system are given: a PID spectrum from 16 O + 18 O fusion-evaporation, and PID and Doppler-corrected -ray spectra from 48 Ti + 12 C Coulomb excitation.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Trinity

At 5:29:45 am Mountain War Time, on July 16, 1945, the world’s first atomic bomb, codenamed Trinity, exploded in a blinding flash 100 feet over a portion of the southern New Mexican desert known as the Jornada del Muerto – the Journey of Death – temporarily blinding a future Nobel Laureate, Richard Feynman. Forty seconds after the detonation, Noble laureate Enrico Fermi dropped small pieces of paper before, during, and after the blast wave passed him. From the lateral dispersion of the paper, he calculated a yield of ten kilotons. Another laureate, I.I. Rabi, won the betting pool for Trinity’s yield. Arriving late, he bought the last available number, eighteen kilotons. The yield was later calculated to be twenty kilotons. On August 9th, a copy of the Trinity device, dubbed Fat Man, was dropped on Nagasaki.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Witness the Trinity test through Lab artifacts

July 16 marks the 77th anniversary of the Trinity test, conducted in a desert in New Mexico. The test subject, an atomic bomb called The Gadget, was successfully detonated from a 100-foot steel tower. This event marks the commencement of the Atomic Age, a new era where fission capabilities could be employed for national security purposes. Shortly after the Trinity test, two Los Alamos-created atomic weapons were released above Japan, helping to end the world’s bloodiest conflict just weeks later. “Trinity was one of the greatest scientific experiments ever,” said NSRC Senior Historian Alan Carr said. “Los Alamos scientists changed the world forever on that day. Not only was it the dawn of the Atomic Age, but also the beginning of the Lab’s eight decades of cutting-edge science and its national security charge.” To preserve this event, and to continue to learn more about this critical moment in history, the National Security Research Center (NSRC) curates a collection of photographs, films, notes, unclassified artifacts and numerous other materials related to the science of the test. Notably, the collection includes a novel material that formed at the site, trinitite, and artifacts from one of the intriguing scientists present at the test, Enrico Fermi.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Trinity University Campus-Wide Deep Dive

In May 2019, staff members from the Engagement and Performance Operations Center (EPOC) and the Lonestar Education And Research Network (LEARN) met with researchers and staff at Trinity University for the purpose of a Campus-Wide Deep Dive into research drivers. The goal of this meeting was to help characterize the requirements for five campus research use cases and to enable cyberinfrastructure support staff to better understand the needs of the researchers they support. Profiled use cases included: Physics and Neuroscience, Computer Science and Engineering, Classical Studies and Archeology, Biological Sciences, and Geosciences. Material for this event included the written documentation from each of the research areas at Trinity University, documentation about the current state of technology support, and a write-up of the discussion that took place in person.

99 GENERAL AND MISCELLANEOUS↗

Visit Lab’s new Trinity website for videos, posters, stories and more

History was made 75 years ago today. In the early morning hours, Los Alamos scientists, engineers, and staff successfully detonated the Gadget – a plutonium, implosion-type nuclear weapon – in the New Mexico desert during the Trinity Test on July 16, 1945. Weeks later, World War II ended and, today, Trinity’s scientific legacy endures. Watch, read and learn how Los Alamos changed the world. Visit the Lab’s new website int.lanl.gov/trinity.

99 GENERAL AND MISCELLANEOUS↗

How did the world’s first atomic bomb get its name? Looking back on the Trinity test on its 76th anniversary

The world’s first-ever atomic bomb is called The Gadget. It was detonated in the New Mexico desert on July 16,1945 during the Trinity test, verifying that an implosion-type plutonium bomb would be successful when released above Nagasaki just weeks later. That atomic bomb was called Fat Man and it was a weaponized version of the Trinity device of The Gadget. According to the longtime lore, the bulbous-looking Fat Man bomb’s name was inspired by British Prime Minister Winston Churchill. After the Thin Man bomb, whose moniker was inspired by the U.S. President Franklin Roosevelt, didn’t come to fruition, the gun-type uranium atomic bomb named Little Boy was developed. It was likely dubbed as such because it was smaller in size.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Plutonium and poetry: Where Trinity and Oppenheimer's reading habits met Literary inspirations, correcting misinterpretation of his famous quote

The Lab’s first director, J. Robert Oppenheimer, was a man of sonnets and scientific synthesis. Oppenheimer’s work at Los Alamos was defined not only by physics and administrative skill, but also by a life philosophy inspired, in part, by literature. The Trinity test, which took place 76 years ago on July 16th in the New Mexico desert, epitomizes this. Known as one of the greatest scientific achievements ever, the successful detonation of the world’s first nuclear weapon marked the dawn of the Atomic Age. Created in just 27, albeit harrowing, months, Oppenheimer and his team at the Los Alamos Lab worked nonstop on this clandestine effort to help end World War II. As he had done throughout his life, Oppenheimer continued to foster his love of literature during the Manhattan Project. Two of his influences were John Donne and the Hindu scripture Bhagavad-Gita. Oppenheimer recalled both during the Trinity test.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

A Nd and Sr isotopic study of the Trinity peridotite Implications for mantle evolution

Field evidence is reported which indicates that the Trinity peridotite in Northern California was partially melted during its rise as part of the upwelling convecting mantle at a spreading center. A Sm-Nd mineral isochron for a plagioclase Iherzolite yielded an age of about 427 Ma which is significantly higher than that expected for depleted mantle during this period. The age is interpreted as the time of crystallization of trapped melt in the plagioclase Iherzolite P-T field, and probably represents the time when the massif was incorporated as a part of the oceanic lithosphere. The Sm-Nd model age of the plagioclase Iherzolite total rock is 3.4 AE. This suggests that the peridotite was derived from a mantle that was depleted early in earth history. Although most available data indicate that the depleted upper mantle has been relatively well stirred through time, the Trinity data suggest that very ancient Nd isotropic values are preserved and chemical and physical heterogeneities are sometimes preserved in the depleted source of midocean ridge basalts as well as the oceanic lithosphere which they intrude.

Jacobsen, S. B.↗

Demonstration of 151 Sm analysis using Trinity nuclear debris samples

Here, the long-lived fission product 151 Sm (T 1/2 ≈ 90 y) present in archived dissolved Trinity nuclear test debris samples was analyzed using liquid scintillation counting and the results were compared to the expected values based upon historical analysis results. The measured 151 Sm activities were found to agree with the expected values within experimental error. This demonstration validates the use of this technique in situations where the sample is too old for traditional shorter half-life radioactive fission product signatures such as 99 Mo (T 1/2 = 2.75 d), 97 Zr (T 1/2 = 16.7 h), 147 Nd (T 1/2 = 10.98 d), and 153 Sm (T 1/2 = 46.3 h), or too dilute for determining fissions through stable isotope ratio measurements.

151Sm↗

Woolwich, Bruceton, Los Alamos: Munroe Jets and the Trinity Gadget

Prewar work on the hydrodynamics of explosives and U.S./UK scientific cooperation well beyond Los Alamos contributed to the design of the explosive lenses for the Trinity gadget. Researchers were deliberately brought together and encouraged to share ideas by the leaders of the wartime laboratory. James Tuck, one of the British mission scientists, made particularly interesting contributions in this area, but this paper is not a claim of British or any other individual parentage. Rather, it highlights the importance of collaboration at Los Alamos and more widely.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Fermi at Trinity

Enrico Fermi estimated the yield of the Trinity test to be about 10 kt by dropping small pieces of paper and observing their motion in the blast wave. This is about 40% of the radiochemically derived value of 25±2 kt that necessarily includes thermal and nuclear radiation that do not contribute to the blast. Although this story is classic, there appears to be no account of how he related his observation to the yield. This paper attempts to reconstruct how he might have done so.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Weapons Radiochemistry: Trinity and Beyond

On July 16, 1945, the Trinity nuclear test exploded in the desert near Alamogordo, New Mexico. A variety of new diagnostic experiments were fielded in an effort to understand the detailed performance of the nuclear device. This paper describes a series of radiochemical experiments that were designed to measure the efficiency and neutron fluence of the test. These experiments, and the scientists who led them, laid the foundation of weapons radiochemistry for decades to come.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗