|The EBEX field team in Ft. Sumner, NM, before the June 2010 engineering flight|
The E and B Experiment (EBEX) is a NASA-funded balloon-borne telescope designed to measure the polarization of the cosmic microwave background (CMB). The experiment will use 1432 transition edge sensor (TES) bolometric detectors read out with a frequency multiplexed SQUID readout. EBEX will observe in three frequency bands centered at 150, 250, and 410 GHz, with 768, 384, and 280 detectors in each band, respectively. This broad frequency coverage will provide valuable information about foreground emission from thermal dust. The polarimetry and signal modulation are achieved using an achromatic half wave plate (AHWP) rotating on a superconducting magnetic bearing and a fixed wire grid polarizer. The 420 square degree observing area and 8' resolution provide sensitivity to an angular power spectrum from 0.2 deg to 5 deg. This will allow EBEX to observe the primordial B-mode signal predicted by inflation on scales of about 0.5 deg and the anticipated lensing B-mode signal at smaller angular scales. Simulations show that EBEX will detect the primordial B-mode signal if the tensor to scalar ratio, r, is 0.1, or it will reduce the current upper limit to ~0.05. This limit assumes that errors due to foreground subtraction are below detector noise, and it does not include systematic uncertainties. The test flight took place in June, 2009, from Ft. Sumner, NM, and the science flight will occur over Antarctica. I will discuss the EBEX instrument and the results from the North American test flight.
For background information on EBEX and the CMB see the following links:
The photos below show the EBEX gondola being delivered from SSL to Nevis and the EBEX gondola suspended.