Development of an active carbon fiber composite mirror

Doel, P.; Kendrew, Sarah; Dorn, Chris; Yates, Chris; Martin, R.; Richardson, I.M.; Evans, Glynn

doi:10.1117/12.551813

Cited by 9 publications

(4 citation statements)

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“…The monolithic Wolter-I mirror has the advantage of reducing the degradation of image performance due to alignment errors, and the reduction of the alignment error is particularly important to manufacture a large-area telescope. However, there are known disadvantages of using CFRP as a substrate for high-precision optics [18][19][20][21][22][23][24][25][26][27][28] and, in particular, x-ray mirrors. 29 One is the microscale deformation of the substrate surface, which is called print-through.…”

Section: Introductionmentioning

confidence: 99%

Effect of barrier layer on moisture absorption of thin carbon-fiber-reinforced plastic mirror substrates

Awaki

Yoshida

Oue

et al. 2019

J. Astron. Telesc. Instrum. Syst.

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Carbon-fiber-reinforced plastic (CFRP) has a higher strength-to-weight ratio and forming flexibility than metals, making it suitable for fabricating lightweight x-ray mirrors. However, CFRP has the disadvantages of print-through and deformation due to moisture absorption, which have prevented its use in optical mirrors. To expand the application of CFRP, we studied the formation of a moisture barrier layer on CFRP substrates. We formed a flattening layer a few micrometers thick on a CFRP substrate, following which we coated the substrate with SiO x as a moisture barrier. The effect of moisture absorption was then evaluated using accelerated aging tests. We found that the diffusivity of the CFRP substrate at 60°C and a relative humidity of 100% was ∼2 × 10 −6 mm 2 h −1 , which is 1/500th that of the barrier-less substrate. In the tests, the moisture absorption rate increased after ∼800 h. As we observed cracks on the flattening layer after 600 h, the rate increase could be associated with these cracks. Considering the damage to the barrier layer, we propose a modified model for the time profile, which is congruent with the observed time profile of the moisture content.

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Section: Introductionmentioning

confidence: 99%

Effect of barrier layer on moisture absorption of thin carbon-fiber-reinforced plastic mirror substrates

Awaki

Yoshida

Oue

et al. 2019

J. Astron. Telesc. Instrum. Syst.

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“…[7][8][9][10][11][12][13][14][15][16] According to the literature, the choice of mirror material and the technique for changing the mirror curvature are two aspects to consider when designing a VCM. This means that a large sagittal variation, which is defined as the central deformation of an optic system, should be provided.…”

Section: Introductionmentioning

confidence: 99%

Carbon-fiber-reinforced polymer variable-curvature mirror used for optical zoom imaging: prototype design and experimental demonstration

et al. 2015

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In recent years, optical zoom imaging without moving elements has received much attention. The key to realizing this technique lies in the design of the variable-curvature mirror (VCM). To obtain enough optical magnification, the VCM should be able to change its radius of curvature over a wide range. In other words, the VCM must be able to provide a large sagittal variation, which requires the mirror material to be robust during curvature variation, require little force to deform, and have high ultimate strength. Carbon-fiber-reinforced polymer (CFRP) satisfies all these requirements and is suitable for fabricating such a VCM. Therefore, in this research, a CFRP prototype VCM has been designed, fabricated, and tested. With a diameter of 100 mm, a thickness of 2 mm, and an initial radius of curvature of 1740 mm, this VCM can provide a maximum 23-μm sagittal variation and a minimum and maximum radius of curvature of 1705 and 1760 mm.

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“…5,6 Finally, a group is working on development of deformable carbonfiber-reinforced mirrors using magnetostrictive actuators. [7][8][9] Related to studies of an ELT with a primary mirror diameter of 50 m ͑the Euro50͒ at Lund Observatory, 10 a conceptual design of a 4-m DM has been undertaken and an actuator test stand built. Here we report on the progress of that work.…”

Section: Introductionmentioning

confidence: 99%

Novel concept for large deformable mirrors

et al. 2006

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Large, high-bandwidth deformable mirrors ͑DMs͒ with thousands of actuators for adaptive optics are of high interest for existing large telescopes and indispensable for construction of efficient future extremely large telescopes. Different actuation and sensing principles are possible. We propose a novel concept using commercially available voice coil actuators attached to the back of the mirror with suction cups and using LVDT sensors on the actuators for local stabilization. Also, a new low-cost sensor for easy measurement of DM displacement or velocity has been developed. It has a sensitivity better than 20 nm and a bandwidth wider than 20 to 1000 Hz. Finally, studies are in progress of global, hierarchical mirror form controllers based on many parallel multiple-input, multiple-output regulators of low order.

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Development of an active carbon fiber composite mirror

Cited by 9 publications

References 0 publications

Effect of barrier layer on moisture absorption of thin carbon-fiber-reinforced plastic mirror substrates

Effect of barrier layer on moisture absorption of thin carbon-fiber-reinforced plastic mirror substrates

Carbon-fiber-reinforced polymer variable-curvature mirror used for optical zoom imaging: prototype design and experimental demonstration

Novel concept for large deformable mirrors

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