Editing Bolometer (section)

== Applications in plasma physics ==

Bolometers play a pivotal role in monitoring radiation in fusion plasmas. The [[Wendelstein 7-X]] (W7-X) [[stellarator]] employs a two-camera bolometer system to capture plasma radiation. This setup is optimized to identify 2D radiation distributions within a symmetrical triangular plasma cross-section. Recent progress includes the refinement of a tomographic reconstruction algorithm, which leans on the principle of relative gradient smoothing (RGS) of emission profiles. This has been effectively applied to the W7-X hydrogen discharges powered by [[electron cyclotron resonance heating]] (ECRH). In terms of hardware, the W7-X bolometers are equipped with metal-resistive detectors. These are distinguished by a 5 μm thick gold absorber, sized 1.3&nbsp;mm in the poloidal direction and 3.8&nbsp;mm toroidally, mounted on a ceramic (silicon nitride Si3N4) substrate. The inclusion of a 50&nbsp;nm carbon layer is strategic, enhancing the detection efficiency for low-energy photons. These detectors are notably attuned to impurity line radiation, covering a spectrum from the very ultraviolet (VUV) to soft x-rays (SXR). Given their resilience and innovative design, they are being considered as prototypes for the upcoming [[ITER]] bolometer detectors.<ref>{{cite journal |last1=Zhang  |first1=D. |last2=Burhenn |first2=R. |display-authors=1|title=Design criteria of the bolometer diagnostic for steady-state operation of the W7-X stellarator |journal=Review of Scientific Instruments |date=2010 |volume=81 |issue=10|pages=10E134|doi=10.1063/1.3483194 |pmid=21033996 |bibcode=2010RScI...81jE134Z |hdl=11858/00-001M-0000-0026-F070-5 |s2cid=3856215 |url=https://doi.org/10.1063/1.3483194|hdl-access=free }}</ref><ref>{{cite journal |last1=Zhang  |first1=D. |last2=Burhenn |first2=R. |display-authors=1|title=Bolometer tomography on Wendelstein 7-X for study of radiation asymmetry |journal=Nuclear Fusion |date=2021 |volume=61|issue=11 |pages=116043|doi=10.1088/1741-4326/ac2778 |bibcode=2021NucFu..61k6043Z |s2cid=238641528 |doi-access=free }}</ref>