The Development of THz Photometers to Observe Solar Flares from a Stratospheric Platform

P. KAUFMANN; E. CORREIA; L.O.T FERNANDES; C.G. GIMENEZ DE CASTRO; A.S. KUDAKA; J.-P. RAULIN; A. VÁLIO; R. MARCON; E.C. BORTOLUCCI; J.A. DINIZ; M.B. ZAKIA; JACOBUS W. SWART; N. MACHADO; A. ABRANTES; C. M. DA SILVA; V. NICOLAEV; A. TIMOFEEVSKY; M. LEBEDEV; A. SHIH; G. HURFORD; R. LIN; V.S. MAKHMUTOV; Y. I. STOZKHOV; A. MARUN; P.PEREYRA; R. GODOY; G. FERNANDEZ; T. VILLELA

Joao Pessoa - Paraíba

Simposio; 15º SBMO Simpósio Brasileiro de Micro-ondas e Optoeletrônica e o 10º CBMag Congresso Brasileiro de Eletromagnetismo; 2012

Sociedade Brasileira de Micro-ondas e Optoeletrônica

The newly found solar flare spectral component with intensities increasing for larger sub-THz frequencies, brings challenging constraints for interpretation. Higher THz frequencies observations are needed to understand the nature of the mechanisms involved. A two-frequency THz photometer system was developed to observe outside the terrestrial atmosphere on stratospheric balloons. Two 76 mm diameter telescopes were designed to observe the whole solar disk detecting small relative temperature changes caused by flares at localized positions at 3 and 7 THz. Golay cell detectors are preceded by low-pass filters to suppress visible and near IR radiation, bandpass filters, and choppers. It can detect temperature variations smaller than 1 K with time resolution of a fraction of a second, corresponding to small burst intensities. The photometers are assembled in a thermal controlled box to which data acquisition and telemetry systems are coupled. A laboratory THz photometer prototype was developed. The SOLAR-T flying model has been completed. It is planned to fly on board of longduration stratospheric balloon flights in 2013-2015. One will be coupled to the GRIPS gamma-ray experiment in cooperation with University of California, Berkeley, USA with one test flight in US, and a 2 weeks flight over Antarctica during local summer. Another flight over Russia (one week) is planned in cooperation with the Lebedev Physics Institute, Moscow, during local summer.