The Mirrortron experiment: A proof of principle test for a method of generating high transient potentials

Thesis/Dissertation · Wed Sep 01 00:00:00 EDT 1993

DOI:https://doi.org/10.2172/10183047· OSTI ID:10183047

Douglass, Scott Roger ^[1]

---

1. Univ. of California, Davis, CA (United States)

The Mirrortron is a concept in which heavy ions are accelerated by a large local transient space potential that is produced in a hot electron plasma. The purpose of this experiment is to begin a proof of principle experiment to investigate the feasibility of producing this space potential and its associated electric field. If a large magnetic field is suddenly generated in a hot electron plasma with a loss-cone distribution, then potentials on the order of the electron temperature are expected. This potential lasts a few tens of nanoseconds. The investigation begins with a theoretical analysis of this phenomenon giving the space potential as a function of the applied magnetic field. The theory is further extended to cases of relativistic electron distributions. This is then followed by design work on a mirror confinement system for hot electrons. In this experiment a 50--100 keV electron temperature plasma is created with electron cyclotron resonance heating using two frequencies of relatively low microwave power. The microwaves are coupled to resonant frequencies of the vacuum chamber. The volume averaged plasma density is measured to be in the 10⁹ cm^-3 range. A strap coil and a flat Blumlein transmission line pulse generator were developed to produce a 150 gauss field within 70 ns. The strap coil was placed at the midplane of the mirror field, where the field is 700 gauss. Based on theoretical estimates and computer simulations a 20 kV potential is expected. Measurement of this potential is derived from the modulation of the current of a monoenergetic electron beam after it passes through the high potential region. The variation in the beam energy allows bunching to occur in transit to the detector.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10183047
• Report Number(s): UCRL-LR-114660; ON: DE93040534; TRN: 93:023896
• Resource Relation: Other Information: DN: Thesis submitted to Univ. of California, Davis, CA.; TH: Thesis (Ph.D.); PBD: Sep 1993
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
43 PARTICLE ACCELERATORS
HILACS
MAGNETIC MIRRORS
ECR HEATING
ELECTRON TEMPERATURE
MAGNETIC FIELDS
ELECTRON SOURCES
X-RAY SPECTRA
MAGNETRONS
INERTIAL CONFINEMENT
MHD EQUILIBRIUM
VACUUM SYSTEMS
700411
430303
INERTIAL CONFINEMENT DEVICES
EXPERIMENTAL FACILITIES AND EQUIPMENT