Reconstitution of Low Bandwidth Reaction History
The goal of the Test Readiness Program is to transition to a 24 month test readiness posture and if approved move to an 18-month posture. One of the key components of the Test Readiness Program necessary to meet this goal is the reconstitution of the important diagnostics. Since the end of nuclear testing, the ability to field diagnostics on a nuclear test has deteriorated. Reconstitution of diagnostics before those who had experience in nuclear testing either retire or leave is essential to achieving a shorter test readiness posture. Also, the data recording systems have not been used since the end of testing. This report documents the reconstitution of one vital diagnostic: the low bandwidth reaction history diagnostic for FY04. Reaction history is one of the major diagnostics that has been used on all LLNL and LANL tests since the early days of nuclear testing. Reaction history refers to measuring the time history of the gamma and neutron output from a nuclear test. This gives direct information on the nuclear reactions taking place in the device. The reaction history measurements are one of the prime measurements the nuclear weapon scientists use to validate their models of device performance. All tests currently under consideration require the reaction history diagnostic. Thus moving to a shorter test readiness posture requires the reconstitution of the ability to make reaction history measurements. Reconstitution of reaction history was planned to be in two steps. Reaction history measurements that have been used in the past can be broadly placed into two categories. The most common type of reaction history and the one that has been performed on virtually all nuclear tests is termed low bandwidth reaction history. This measurement has a time response that is limited by the bandpass of kilometer length coaxial cables. When higher bandwidth has been required for specific measurements, fiber optic techniques have been used. This is referred to as high-bandwidth reaction history. The first step in the reconstitution of reaction history was thus naturally the reconstitution of the low-bandwidth capability in FY04. This will be followed in FY06 by the reconstitution of the high bandwidth capability. The reconstitution of the low-bandwidth reaction history measurement was done in several phases. First the status of legacy equipment has been ascertained. Existing detectors, cables, and recording systems have been inventoried, characterized and, for the most part, satisfied the specifications of the test program and are still useable. The ability to obtain replacement equipment is now available. Modern low-bandwidth fiber optic recording equipment which was similar to systems used on the old tests, has been evaluated. The ability to characterize and calibrate detectors and other components has been reestablished. New scientists and engineers have been working with designated mentors. These mentors participated on numerous shots during the old test program. Finally as a proof test, two hypothetical test scenarios were proposed: one each from LLNL and LANL. The LANL event was called ALPHA and the LLNL event was called POPOUT. The reaction history diagnostics for these two hypothetical underground tests were completely laid out and analyzed to make sure that the diagnostic could be successfully fielded within a 24 month time frame. In addition as part of a training exercise a reaction history trailer was reconstituted. This system was configured using a combination of new and experienced technical personnel and data analysts in collaboration with LLNL and LANL event physicists.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15011793
- Report Number(s):
- UCRL-TR-210578; TRN: US0501444
- Resource Relation:
- Other Information: PBD: 11 Nov 2004
- Country of Publication:
- United States
- Language:
- English
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