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Leal Cidoncha, Esther

Publications and source records attributed to Leal Cidoncha, Esther.

10 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

169 Tm(n,$\gamma$) cross section measured at DANCE

During the US nuclear testing program, known tracer materials could be loaded into the device prior to detonation. If those materials had activation products from nuclear reactions, they could be recovered and counted post-test to study how they transmuted during the neutron exposure. This information may be used to try to infer information about the physical conditions during the detonation. These materials are often referred to as “radiochemical detectors” or “radiochemical tracers”. Thulium, which has only one stable isotope, thulium-169, is one such material that may be employed as a detector.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Background simulations for DANCE, FP-14 considering the Mark IV spallation target

With the installation of the Mark-IV target at LANSCE in 2022 significant changes of the beam-related backgrounds at DANCE are observed. DANCE is located at flight path 14 (FP-14) in the experimental area 2 (ER-2) at LANSCE. This new background is so severe that the array is not operational for several microseconds after the protons hit the spallation target (Figures 1 - 3).

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Report on the DANCE/FP14 Beam Profile and plans for the CY23 LANSCE run cycle

During the beam outage at the beginning of calendar year 2022, the Lujan Center Spallation Target was replaced with the Mark-IV design. Most notably, this included a rotated tungsten disk (for neutron production) in the direct line of sight of the upper tier flight-paths (FPs 12-15), which include DANCE, DICER, and the general-purpose flight path 12, all focused on nuclear physics measurements. This change was made in order to significantly improve both the neutron flux and the time-of-flight resolution for neutrons above 1 keV. Details of the design and motivation can be found in Zavorka et al. 2018. Due to the changes in the spallation target, significant work was required to provide new shutters and shielding for the upper tier flight paths. While the planned beam deliver was for September of 2022, because of delays in the installation process, first beam to DANCE was received the afternoon of 22 Nov 2022. Due to accelerator reliability issues, a total of only 18 days of beam were available for the run cycle. Approximately 90 days of development were planned for understanding the neutronic proper<es of the new spallation target. Most of this work could not be completed. Two measurements were completed, of which one will be discussed here.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

DANCE and NEUANCE measurements of $^{233}U(n, \gamma$) (Q3 Report to NCSP on FY22)

The experiment was performed at the end of the CY20 runcycle and CY21. A total of 20 days were measured using the 20 mg sample, and the 10 mg sample was placed in the beam for a total of 2 days. The rest of the beam time was used to measure radioactive γ sources for energy calibration, background measurements, and tests to define the 233 U windows required during the data taking.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Report to NCSP on FY22 DANCE and NEUANCE measurements of 233 U((η, γ)

The experiment was performed at the end of the CY20 runcycle and CY21. A total of 20 days were measured using the 20 mg sample, and the 10 mg sample was placed in the beam for a total of 2 days. The rest of the beam time was used to measure radioactive γ sources for energy calibration, background measurements, and tests to define the 233 U windows required during the data taking.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

233 U(n,$\gamma$) measurements at LANSCE [Slides]

A new measurement at LANSCE combined DANCE and NEUANCE at the end of 2020 and 2021. The 233 U material was provided by Oak Ridge National Laboratory (December 2020).Two samples of 10 mg and 20 mg of 233 U have been prepared at LANL by Evelyn M. Bond (December 2020). The experiment was performed in December 2020 and June/July 2021. Data analysis is ongoing to extract capture data knowing fission. LANL is looking forward to delivering the capture/fission ratio from (1-300) keV by the end of the FY2022.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Report to NCSP on FY21 DANCE and NEUANCE measurements of 233 U(n, γ)

In order to complete the statistics needed above 10 keV after the experiment performed in December 2020, a production measurement of the 233 U capture cross section, using the thick target (~20 mg) was proposed for the CY21 runcycle. Through collaboration with the DANCE experimental team, we arranged for the NEUANCE array to stay in place in the CY21 run cycle until the 233 U measurement was complete in June-July 2021, further reducing systematic uncertainties in the measurement. The measurement was performed over 10 days with the 20 mg sample, and the 10 mg sample was placed in the beam for 1 day. The rest of the beam time was used to measure radioactive γ sources for energy calibration, and background measurements and tests to define the 233 U windows required during the data taking. The NEUANCE detector placed inside the DANCE cavity is shown.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Report to NCSP on FY21 DANCE and NEUANCE measurements of 233 U(η, γ)

The experiment was performed by the end of the CY20 runcycle at LANSCE. Due to transportation issues the material arrived at LANL on 1st December. Two 233 U samples, of 20 mg and 10 mg were produced at LANL by stippling, which has proved a robust, cost-effective method for producing actinide samples in the range of 1-20 mg in a small (<1 cm) diameter with very high efficiency. The 20 mg sample was placed inside NEUANCE on FP14 on 11th December, was measured over 10 days, and the 10 mg sample was placed in the beam for 1 day. The rest of the beam time was used to measure radioactive γ sources for calibration, background measurements and tests to define the 233 U windows required during the data taking, also some measurements were done with a 235 U sample to cross-check the performance and the systematics.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2021

First NCSP Sponsored Experiment at LANSCE

Uranium-233 has played an important role in solution critical experiments going back to the 50's and 60's, including experiments from the Falstaff Program. More recently, management of legacy 233 U material across the DOE complex has led to a requirement for improved nuclear cross sections.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗