Coatings on inner surfaces of particle containment chambers

A plasma chamber to contain a plasma, the plasma chamber comprising:

• a wall surrounding a volume in which the plasma is contained when the plasma chamber is in operation;
• and
• a coating in thermal communication with an inner surface of the wall to receive electromagnetic radiation including X-rays from the volume, a portion of the X-rays having a range of energies, wherein:
• a first thermal conductivity of the coating is greater than a second thermal conductivity of the wall;
• a thickness of the coating is at least one-half a penetration depth for X-rays in the range of energies;
• and
• at least 50% of the X-rays having the range of energies are absorbed within 1 millimeter of the inner surface of the wall without the coating present.

A system, comprising:

• a plasma chamber having a wall extending around an inner volume, the plasma chamber adapted to support a vacuum in the inner volume, the wall of the plasma chamber having a thermal conductivity no greater than 5 W m−1 K−1;
• a plasma source to generate a plasma and to inject the plasma into the inner volume of the plasma chamber;
• at least one gas inlet coupled to the plasma source, to introduce a gas or a gaseous mixture into the plasma source;
• and
• a plurality of electromagnetic coils arranged to generate a magnetic field within the plasma chamber, such that interaction of particles of the plasma with the magnetic field generates electromagnetic radiation including X-rays, a first portion of the X-rays being absorbable by the wall of the plasma chamber to cause heating of the wall;
• wherein the plasma chamber further includes a coating comprising at least one of bort, boron nitride, graphite, or diamond, the coating disposed on an inner surface of the wall of the plasma chamber to absorb at least a second portion of the X-rays included in the first portion of the X-rays, such that localized peak heating of the wall near the inner surface that occurs during operation of the system due to absorption of the first portion of the X-rays is reduced compared to absorption that would occur of the first portion of the X-rays without having the coating present.