The Swedish-ESO PI Instrument (SEPIA) was successfully reinstalled at APEX last August. The instrument contains a dual polarization sideband-separating ALMA band 5 receiver (covering 159 to 211 GHz), and a new dual-polarization sideband-separating Band 9 receiver, replacing the previous double sideband receiver. This new facility receiver has an excellent sideband rejection ratio exceeding 15 dB at all frequencies, which is particularly important in Band 9 where there are many atmospheric absorption lines. In addition, the new receiver covers an extended tuning range from 578 to 738 GHz, adding 24 GHz on the lower edge and 18 GHz on the upper edge. Both receivers are offered in ESO Period 103 (see the Call for Proposals).
SEPIA Reinstalled at APEX with an Upgraded Band 9 Receiver
A new dual polarization sideband-separating Band 7 receiver covering 272 to 376 GHz is expected to be installed in early 2019 to complete the full receiver complement of SEPIA.
Image caption: Denis Meledin and Erik Sundin from the Group of Advanced Receiver Development (GARD, Gothenburg, Sweden) working on the installation of the SEPIA instrument in the Nasmyth A cabin at APEX. (Credit: Mathias Fredrixon, GARD)