Browse Prior Art Database

First Wall Material for a Controlled Thermonuclear Reactor

IP.com Disclosure Number: IPCOM000084551D
Original Publication Date: 1975-Nov-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Lurio, A: AUTHOR [+2]

Abstract

The first wall of a controlled thermonuclear reactor must be able to withstand high temperatures, and intense ion-beam bombardment, yet it must be transparent to 14 MEV neutrons which carry the reactive energy out of the machine.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 80% of the total text.

Page 1 of 2

First Wall Material for a Controlled Thermonuclear Reactor

The first wall of a controlled thermonuclear reactor must be able to withstand high temperatures, and intense ion-beam bombardment, yet it must be transparent to 14 MEV neutrons which carry the reactive energy out of the machine.

Fig. 1 is an illustrative cross-sectional view of a controlled thermonuclear reactor showing the location of the first wall. It was believed that the first wall should be made of V or Nb metals which have great transparency to high-energy neutrons. However, it was calculated recently that the sputtering of these surfaces by ions leaking from the plasma core would be sufficient to cool the plasma below the reaction threshold.

A proposal for the first wall has been to use carbon, as it can sputter at 10 times the rate of V or Nb metal before it cools the plasma below threshold. However, carbon is a neutron absorber and reflector, so the carbon wall must be kept thin. Because of the convoluted geometry of the vacuum chambers, they cannot be disassembled for first wall replacement. It has been suggested to put curtain rods along the inner walls, as shown by Fig. 2.

The use of carbon cloth allows replacement of the entire wall from a small access port. The disadvantage is that the carbon cloth must be about 5 x 10/6/ atoms/cm/2/ (approx. 20 mills) thick for structural support.

It is proposed herein that a much thinner carbon first wall can be obtained by in situ pyrolysis of a hydroca...