Balloon-borne heterodyne stratospheric limb sounder TELIS ready for flight

摘要

TELIS (TErahertz and submm LImb Sounder) is a three-channel balloon-borne heterodyne spectrometer for atmospheric research. The observational techniques of TELIS can be compared to the presently flying MLS instrument on board NASA's EOS-Aura satellite, but TELIS is built with a new generation of cryogenic heterodyne detectors and novel compact systems suitable for integration into the confined space of a balloon borne cryostat. TELIS will fly on the MIPAS-B2 gondola. The two instruments together will yield the most complete set of stratospheric constituents, measured so far. TELIS is a cooperation between the European institutes DLR (Pi-institute), RAL and SRON. First flight foreseen in the spring of 2008 from Teresina, Brasil. The three TELIS receivers provide simultaneous vertical profile measurement of a range of molecules. The 500 GHz channel is developed by RAL and will produce vertical profiles of BrO, ClO, O_3 and N_2O. The 1.8 THz channel is developed by DLR and will mainly target the OH radical, and will also measure HO_2, HCl, NO, NO_2, O_3, H_2O, O_2 and HOCl. Finally the 480 - 650 GHz channel is developed by SRON and IREE and will measure profiles of ClO, BrO, O_3, HCl, HOCl, H_2O and its 3 isotopomers, H_2O_2, NO, N_2O, HNO_3, CH_3Cl and HCN.In this paper, the science and technology of TELIS will be discussed with emphasis on the channel developed by SRON. It contains a Superconducting Integrated Receiver (SIR), which combines on a 4 × 4 mm~2 chip the low-noise SIS mixer and its quasioptical antenna, a superconducting phase-locked Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and a SIS harmonic mixer (HM) for FFO phase locking. The latest results from the pre-flight test and integration campaigns will be presented.