The receiver system of the fast ion and alpha particle diagnostic at JET

J. A. Fessey

doi:10.1117/12.2298558

30 August 1993 The receiver system of the fast ion and alpha particle diagnostic at JET

J. A. Fessey

Proceedings Volume 2104, 18th International Conference on Infrared and Millimeter Waves; 21043I (1993) https://doi.org/10.1117/12.2298558
Event: 18th International Conference on Infrared and Millimeter Waves, 1993, Colchester, United Kingdom

Abstract

A 140GHz collective Thomson scattering diagnostic is presently being built to study the distribution of fast ions and alpha- particles within the JET plasma. A technical overviews and description of the mm-wave transmission system2 are presentedin other contributions to this conference. This paper will discuss the design of the multi-channel super heterodyne receiverand dedicated data acquisition system. 140GHz radiation from a gyrotron (250kW average, 5s pulse duration) is injected intothe plasma where it is scattered by the shielding electrons moving with each ion. The receiver is designed to measure thespectral power density of the scattered radiation (10-19- 10-16W/Hz) against an electron cyclotron background emission ofmuch higher magnitude (1 0-16w/He .) This is achieved by amplitude modulating the probing beam and synchronousdetection of the scattered signal. Refraction of the beams within the plasma can be important at high densities and theposition of the scattering volume will therefore change as the plasma evolves. A system of 'slave' receivers is being developedto track this movement and to control the trajectory of the main receiver beam by adjusting the orientation of the antenna.

Citation Download Citation

J. A. Fessey "The receiver system of the fast ion and alpha particle diagnostic at JET", Proc. SPIE 2104, 18th International Conference on Infrared and Millimeter Waves, 21043I (30 August 1993); https://doi.org/10.1117/12.2298558

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available