Affiliation:
1. Hebei Key Laboratory of Compact Fusion, Langfang 065001, China and ENN Science and Technology Development Co., Ltd., Langfang 065001, China
Abstract
The Energy iNNovation’s XuanLong-50 is a spherical torus experiment with up to 10 s plasma operation duration. A 3 J/50 Hz pulsed laser is used in the Thomson scattering diagnostic system that is developed to measure the time evolutions of plasma electron temperature and density profiles. The expected laser pulse number is about 7.5 × 106/year with a power load of 150 W. To meet at least 1-year lifetime requirement, a Chevron type beam dump with polished molybdenum plates is designed and fabricated, which absorbs the laser beam energy in a 3D structure to reduce the laser fluence deposited on the material surface. To prevent the backscattered stray light from interfering with the Thomson scattering measurements, a 7.5 m beam path with folding mirrors is set between the beam dump and the plasma scattering volumes. Details of the beam dump design procedure including the laser beam profile control, multi-pulse laser damage threshold, heat dissipation, Zemax modeling, folding mirror selection, and beam path enclosure are presented together with the testing results.
Funder
Hebei Province Science and Technology Support Program
Reference13 articles.
1. Thomson scattering diagnostic system for the XuanLong-50 experiment
2. Development of KSTAR Thomson scattering system
3. Prospects for the Thomson scattering system on NSTX-Upgrade
4. D. G. Nilson, T. N. Carlstrom, C. L. Hsieh, B. W. Stallard, and R. E. Stockdale, “Central Thomson scattering upgrade on DIII-D,” General Atomics Report No. GA-A22722, 1997 and in 17th IEEE/NPSS Symposium Fusion Engineering (Cat. No. 97CH36131), 1997, pp. 791–794, Vol. 2.
5. Development of a nine spatial point, multipulse Thomson scattering diagnostic