Submillimeter Instrumentation


As part of my dissertation work, I have developed the 2nd generation Redshift(z) and Early Universe Spectrometer (Figure 2; Ferkinhoff et al. 2010). My work has primarily focused on the detector and the detector readout electronics. ZEUS-2 is a moderate resolution (R~1000), echelle grating spectrometer optimized for the detection of faint and broad submillimeter lines from distant galaxies. The spectrometer employs three bolometer arrays with a total of 537 pixels that operate at ~120mK and are readout via Superconducting Quantum Interference Device (SQUID) multiplexers, adding significant complexity to read out the detetctor. Cooling is provided by a pulse-tube cooler and two-stage adiabatic demagnetization refrigerator. Using different filters in front of the detector, ZEUS-2 can observe lines in 7 different atmospheric windows from 200 to 850 microns. We successfully commissioned ZEUS-2 on the Attacama Pathfinder EXperiment (APEX) in November 2012 detecting the [CII] line from a galaxy at z~1.8 (Ferkinhoff et al. 2014)




(left) ZEUS-2 mounted in the reciever cabin of the Atacama Pathfinder Experiment (APEX) in the Atacama Desert of Chile. (right) First light ZEUS-2 spectrum of the [CII] 158 micron line from the high-z galaxy SDP11.