dorsal/arxiv
View SchemaX-ray Measurement of the subpixel structure of the XMM EPIC MOS CCD
| Authors | H. Tsunemi, K. Yoshita, A. D. Short, P. J. Bennie, M. J. L. Turner, A. F. Abbey |
|---|---|
| Categories | |
| ArXiv ID | physics/9910002 |
| URL | https://arxiv.org/abs/physics/9910002 |
| DOI | 10.1016/S0168-9002(99)00762-7 |
Abstract
We report here the results of a mesh experiment to measure the subpixel structure of the EPIC MOS CCDs on board the XMM X-ray observatory. The pixel size is 40$\mu$m square while the mesh hole spacing is 48$\mu$m, a combination quite different from our standard mesh experiment. We have verified that this combination functions properly and have analyzed the CCD structure with sub-pixel resolution. The EPIC MOS CCD has an open electrode structure to improve detection efficiency at low energies. We obtained the distribution of various grades of X-ray events inside the pixel. A horizontally split two-pixel event is generated near the channel stop which forms a straight vertical pixel boundary whereas a vertically split two-pixel event is generated where the potential due to the thinned gate structure forms a wavy horizontal pixel boundary. Therefore, the effective pixel shape is not a square but is distorted. The distribution of X-ray events clearly shows that the two etched regions in each pixel, separated by the bridging finger of the enlarged (open) electrode. We measured the difference in X-ray transmission between the conventional and open regions of the pixel using O-K and Cu-L X-ray emission lines, and found it to be consistent with an electrode thickness comprising $0.2\pm0.1\mu$m of Si and $0.6\pm0.2\mu$m of SiO2.
{
"annotation_id": "ee790cf7-674c-4f20-ae06-4c9816bfc2a0",
"date_created": "2026-03-02T18:01:24.833000Z",
"date_modified": "2026-03-02T18:01:24.833000Z",
"file_hash": "1ae2b9916fa5f9ef3df3bf312dd9fac0195306ec7f9156e97dd2d8804599efc4",
"private": false,
"record": {
"abstract": "We report here the results of a mesh experiment to measure the subpixel\nstructure of the EPIC MOS CCDs on board the XMM X-ray observatory. The pixel\nsize is 40$\\mu$m square while the mesh hole spacing is 48$\\mu$m, a combination\nquite different from our standard mesh experiment. We have verified that this\ncombination functions properly and have analyzed the CCD structure with\nsub-pixel resolution. The EPIC MOS CCD has an open electrode structure to\nimprove detection efficiency at low energies. We obtained the distribution of\nvarious grades of X-ray events inside the pixel. A horizontally split two-pixel\nevent is generated near the channel stop which forms a straight vertical pixel\nboundary whereas a vertically split two-pixel event is generated where the\npotential due to the thinned gate structure forms a wavy horizontal pixel\nboundary. Therefore, the effective pixel shape is not a square but is\ndistorted. The distribution of X-ray events clearly shows that the two etched\nregions in each pixel, separated by the bridging finger of the enlarged (open)\nelectrode. We measured the difference in X-ray transmission between the\nconventional and open regions of the pixel using O-K and Cu-L X-ray emission\nlines, and found it to be consistent with an electrode thickness comprising\n$0.2\\pm0.1\\mu$m of Si and $0.6\\pm0.2\\mu$m of SiO2.",
"arxiv_id": "physics/9910002",
"authors": [
"H. Tsunemi",
"K. Yoshita",
"A. D. Short",
"P. J. Bennie",
"M. J. L. Turner",
"A. F. Abbey"
],
"categories": [
"physics.ins-det"
],
"doi": "10.1016/S0168-9002(99)00762-7",
"title": "X-ray Measurement of the subpixel structure of the XMM EPIC MOS CCD",
"url": "https://arxiv.org/abs/physics/9910002"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "89c4d34f-be62-4841-a109-9228e208a2c1",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}