D-dot and B-dot monitors for Z-vacuum-section power-flow measurements
- and others
The 36-module Z accelerator--designed to drive z-pinch loads at currents up to 20 MA--is contained in a 33-m-diameter tank with oil, water, and vacuum sections. The peak total forward-going power in the 36 water-section bi-plate transmission lines is approximately 63 TW. nine transmission lines deliver power to each of the four vacuum-section levels (referred to as levels A (the uppermost), B, C, and D). New differential D-dot and B-dot monitors were developed for the Z vacuum section. The D-dots measure voltage at the insulator stack. The B-dots measure current at the stack and in the outer magnetically-insulated transmission lines. Each monitor has two outputs that allow common-mode noise to be canceled to first order. The differential D-dot has one signal and one noise channel; the differential B-dot has two signal channels with opposite polarities. Each of the two B-dot sensors in the differential B-dot monitor has four 3-mm-diameter loops and is encased in copper to reduce flux penetration. For both types of probes, two 2.2-mm-diameter coaxial-cables connect the outputs to a Prodyn balun for common-mode-noise rejection. The cables provide reasonable bandwidth and generate acceptable levels of Compton drive in Z`s bremsstrahlung field. A new cavity B-dot is being developed to measure the total Z current 4.3 cm from the axis of the z-pinch load. All of the sensors are calibrated with 2--4% accuracy. The monitor signals are reduced with Barth or Weinschel attenuators, recorded on Tektronix 0.5-ns/sample digitizing oscilloscopes, and software cable compensated and integrated.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 515597
- Report Number(s):
- SAND--97-1949C; CONF-9706113--8; ON: DE97007980
- Country of Publication:
- United States
- Language:
- English
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