Improved modeling of surface charge distributions in electret ionization chambers

A literature review on space-charge electrets, covering the time period 1987 to 1996, is presented. The review starts out with a discussion of new inorganic and organic electret materials which also includes silicon based single and double layers. This is followed by a review of recent work on methods for measuring charge distributions. New results obtained with these methods on a number of differently charged materials are surveyed, together with data for charge transport and charge decay. Of particular significance is the superb charge storage capability of silicon dioxide/silicon nitride double layers which was discovered only very recently. The review closes with a survey of new, or improved electret applications.

show abstract

“…Improved modeling [147,150] as well as extensive field tests [148] have been performed for such chambers.…”

Section: Electret Coatings For Improved Solar Cellsmentioning

confidence: 99%

Space-charge electrets

Kressmann

Sessler

Gunther

1996

IEEE Trans. Dielect. Electr. Insul.

119

View full text Add to dashboard Cite

show abstract

Charge transport and storage in the radiation‐charged electret ionization chamber

MacDonald

1996

Medical Physics

View full text Add to dashboard Cite

Numerical calculations of time‐dependent charge distributions are presented and compared with distributions measured on radiation‐charged electrets made of thin polymer films, which are charged and discharged in a radiation‐charged electret ionization chamber (REIC) through the application of ionizing radiation. The chamber resembles a parallel plate ionization chamber, and has a thin film of polymer covering the collector and guard‐ring electrodes. Calculations are performed by solving Laplace's equation for the true geometry of the charging/discharging set‐up, then applying estimates of ion‐density distributions generated from known scattering distributions and/or simpler approximations. Measurements of radiation induced conductivity (RIC) are presented and fitted to an empirically derived analytical model, and the effects of RIC on the operation of a radiation dosimeter based on the electret are investigated and discussed. Short‐term and long‐term charge decay from the electret is measured and fitted to a previously developed model. The effects of post‐charging heat treatment of the radiation‐charged electret are presented and discussed. Last, the dosimetric characteristics of the REIC are considered in light of those physical aspects investigated here.

show abstract

Improved modeling of surface charge distributions in electret ionization chambers

Cited by 2 publications

References 10 publications

Space-charge electrets

Space-charge electrets

Charge transport and storage in the radiation‐charged electret ionization chamber

Contact Info

Product

Resources

About