Mannhart JRSE (3 of 3) (image) American Institute of Physics Share Print E-Mail Caption This is a micrograph of the W-grid used as gate in the test generator. The holes have a diameter of ~0.6 mm. Credit J.Mannhart/MPG.de Usage Restrictions This image may be used only with appropriate caption and credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.