A new ALMA development study, titled 'Next-Generation ALMA Vacuum Windows Sub-Wavelength Surface Structuring,' was officially kick-off at Chalmers university on 22 September 2026. The study is led by the Group of Advanced Receiver Development (GARD), Chalmers University, Gothenburg, Sweden in collaboration with the NOVA sub-mm group, in Groningen, the Netherlands.
Development study on the next-generation ALMA vacuum windows by GARD kicks off
Published: 22 Sep 2026
The study team and ESO participants inside the Chalmers clean room around the laser ablation system, which will be one of the key equipment used during the study.
The study aims to improve receiver signal path transmission and reduce reflections at the vacuum windows by developing new generation windows with advanced antireflection structures. To achieve this, a variety of manufacturing techniques - including CNC micromachining and femtosecond laser ablation - and multiple materials like silicon, quartz, and ultra-high molecular weight polyethylene will be investigated. The laser ablation system housed at Chalmers clean room will serve as one of the key equipment pieces to achieve these precise sub-wavelength structures. These technologies and material combinations will be tailored to the demanding requirements of in particular ALMA Bands 6 through 10. By minimizing signal loss through optimized window designs, while ensuring compliance with other ALMA requirements including environmental, the project directly supports technical evolution and sensitivity goals required for future ALMA receiver upgrades programmes.
You can read more about European Development Studies for ALMA here.
Contributed by Carlos de Breuck