The effects of gamma-irradiation on thermally stimulated discharge current spectra in low-density polyethylene

Chen, G.; Fouracre, R.A.; Banford, H.M.; Tedford, D.J.

doi:10.1016/1359-0197(91)90030-6

Cited by 17 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous work using TSDC [1,5] revealed that a radiation atmosphere could influence charge trapping features, and more charge was found within the sample irradiated in air compared to those irradiated in nitrogen or vacuum. However, the understanding of charge trap generation and its effect on charging behaviour after ionising radiation is limited.…”

Section: Introductionmentioning

confidence: 99%

“…The effect of irradiation in polymer insulator has been studied for many years through thermally simulated discharge current (TSDC), electrical conduction and most recently space charge trapping [5,6]. The increase in the presence of trapped charge and trapping characteristics after ionising radiation is generally attributed to different structural defects [1,5]. In partially crystallised polymers such as low density polyethylene (LDPE), these traps are thought to be "cavity" defect traps in the amorphous region and defects at the crystalline surfaces.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Effect of Gamma Irradiation on Space Charge Behaviour and Dielectric Spectroscopy of Low-density Polyethylene

Chen

Dissado

et al. 2007

2007 IEEE International Conference on Solid Dielectrics

Self Cite

View full text Add to dashboard Cite

Abstract:The influence of gamma irradiation on low-density polyethylene (LDPE) has been studied through space charge measurement and dielectric spectroscopy. Commercial LDPE film with a thickness of 100µm was irradiated with γ-rays at a dose rate of approximately 10kGy/h to different doses up to 100kGy in an atmosphere of air, vacuum and nitrogen respectively. Space charge profiles vary depending on irradiation environments and radiation dose. The space charge profile of a sample after irradiation at 100kGy in air is more complicated than those irradiated in vacuum and nitrogen at same dose. More importantly, the space charge decay rate for the irradiated samples is slower than that of the virgin sample, indicating that the irradiation had changed the material by the generation of deep traps for space charge. Irradiation in air also produced changes in the dielectric spectrum in the frequency range between 10 -3 Hz and 10 6 Hz where the imaginary part of the permittivity was found to be about one order of magnitude higher than that of the virgin sample (~10 -4 ). This was attributed to oxidation as samples with the same (or lower) radiation dose in vacuum or nitrogen showed no pronounced difference to that of virgin samples.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Effect of Gamma Irradiation on Space Charge Behaviour and Dielectric Spectroscopy of Low-density Polyethylene

Chen

Dissado

et al. 2007

2007 IEEE International Conference on Solid Dielectrics

Self Cite

View full text Add to dashboard Cite

show abstract

“…The same is obviously true for the depolarization process, where carrier drift now occurs under the added complication of local electric fields. Charge trapping in crystalline polymers has been the subject of many previous works and these effects are attributed to different structural defects [17][18][19][20][21][22][23][24][25][26][27][28][29]. Fleming has considered the formation of the ''cavity'' traps in the amorphous regions of the polymer [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

Polyethylene crosslinked in different media: structural changes versus dielectric behaviour

et al. 2014

View full text Add to dashboard Cite

Changes in the structure and dielectric properties of low-density polyethylene were created by gamma irradiation in air, deionised water and nitrogen. Role of irradiation media on dielectric and charge trapping behaviour was studied through dielectric loss and thermally stimulated discharge current measurements. Changes in magnitude, position and activation energy of all dielectric relaxations (c, b and a) were found to be dependent on crosslinking and oxidative degradation, two competitive processes which can be tuned by radiation dose and media. Largest changes in the position and activation energy were found for the b relaxation due to its cooperative nature.

show abstract

“…It has been suggested that radiation may give rise to the presence of trapped charge within the material, the trapping characteristics of which may be influenced by these radiation-induced structural alterations. Earlier work related particularly to the effects of radiation on the electrical behaviour of low-density polyethylene (LDPE) has shown that a radiation environment can influence the thermally stimulated discharge current (TSDC) spectra in the high temperature region, with more charge being found within the sample irradiated in air compared to those irradiated in nitrogen [5]; the dc electrical conductivity of LDPE irradiated in air is significantly greater than of material irradiated in nitrogen [6]; and the pre-breakdown transient current pulse activity in LDPE under direct stress has been demonstrated to be much greater in material irradiated in air compared to that irradiated in nitrogen [7]. It has generally been considered that space charge played a role in the above behaviour of irradiated materials.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Gamma Irradiation on Space Charge in LDPE

Chen

2006

2006 IEEE 8th International Conference on Properties and Applications of Dielectric Materials

View full text Add to dashboard Cite

In the present paper, we report an investigation on the effect of radiation environment on space charge in low density polyethylene (LDPE). LDPE thin films of ~100 µm were irradiated at a dose rate of approximately 1 kGy/h using a 60 Co gamma source. The samples were irradiated in air, vacuum and nitrogen gas at room temperature to various doses from 5 to 100 kGy. Space charge measurements were carried out using the pulsed electroacoustic (PEA) technique. The applied electric field in all cases is 50 kV/mm. It has been found that the space charge dynamics in the irradiated samples are different from the fresh (un-irradiated) sample and affected by irradiation environment. Although the oxidation of the samples in air may play an important role in the observed differences, charge dynamics in the samples irradiated in vacuum and pure nitrogen gas are also different.

show abstract

The effects of gamma-irradiation on thermally stimulated discharge current spectra in low-density polyethylene

Cited by 17 publications

References 8 publications

The Effect of Gamma Irradiation on Space Charge Behaviour and Dielectric Spectroscopy of Low-density Polyethylene

The Effect of Gamma Irradiation on Space Charge Behaviour and Dielectric Spectroscopy of Low-density Polyethylene

Polyethylene crosslinked in different media: structural changes versus dielectric behaviour

The Influence of Gamma Irradiation on Space Charge in LDPE

Contact Info

Product

Resources

About