8/12/201514th RHESSI Workshop 1 Dale E. Gary, Center for Solar-Terrestrial Research, Physics Department, NJIT

2 8/12/201514th RHESSI Workshop Central array dishes tracking the Sun. EOVSA has 13 such antennas, operating at GHz GHz 400 MHz ~ 40 MHz

8/12/201514th RHESSI Workshop 3 Model images and EOVSA simulation for 16 representative frequencies Example spectra at several points in the image data cube Theoretical fit of the spectra to obtain physical parameters, such as this map of magnetic field strength Gary et al. (2013)

8/12/201514th RHESSI Workshop 4

8/12/201514th RHESSI Workshop 5

8/12/201514th RHESSI Workshop 6

8/12/201514th RHESSI Workshop 7 Amplitude Offset FWHM Background

8/12/201514th RHESSI Workshop 8

8/12/201514th RHESSI Workshop 9

8/12/201514th RHESSI Workshop 10

8/12/201514th RHESSI Workshop 11

8/12/201514th RHESSI Workshop 12

8/12/201514th RHESSI Workshop 13

8/12/201514th RHESSI Workshop 14

8/12/201514th RHESSI Workshop 15

8/12/201514th RHESSI Workshop 16

8/12/201514th RHESSI Workshop 17

8/12/201514th RHESSI Workshop 18

8/12/201514th RHESSI Workshop 19

8/12/201514th RHESSI Workshop 20 Baseline 1-2 Baseline 1-3 Baseline 2-3 Baseline 3-4

8/12/201514th RHESSI Workshop 21 C1-level

8/12/201514th RHESSI Workshop 22

8/12/201514th RHESSI Workshop 23

8/12/201514th RHESSI Workshop 24

 To convert X, Y linear polarization to R, L circular, timing is all important.  Different cable lengths for X and Y channels must be carefully compensated.  R = X  iY,  L = X  iY  Calculation done digitally 8/12/201514th RHESSI Workshop 25 E X Y

8/12/201514th RHESSI Workshop 26

8/12/201514th RHESSI Workshop 27  Completely refurbished 27-m antennas (controller, motors, cabling, limit switches)  New He-cooled receivers—first one to be installed !  Provides sensitivity to use hundreds of calibration sources and short calibration times.

 EOVSA is a fantastically capable, solar-dedicated radio array that is now beginning to obtain science- quality data.  The fundamental challenge of sampling the entire GHz radio spectrum at 1-s cadence has been met.  There are several milestones ahead of us to reach the goal of full spectral imaging, but we expect these to come quickly over the next few months.  EOVSA plays the role of a FASR-demonstrator (10% in size and cost), and we expect it demonstrate the exciting science to come with a larger, broader-band, higher-resolution instrument. 8/12/201514th RHESSI Workshop 28