Torsten Böker TIPS May 2, 2002 NICMOS post-cooldown detector performance 1) SMOV status 2) Dark current 3) Quantum efficiency 4) “First light”, focus and image quality 5) SMOV outlook

Thermal history since NICMOS switch-on (on April 19) Transition to detector control Transition to Ne control Setpoint to 72 K Setpoint to 72.5 K

X X X X

Filter wheel test (G. Schneider, K. Noll, L. Mazzuca, E. Roberts) - NICMOS filter wheels have motion sensor only on the motors, not on the wheels themselves - Concern about breaking the wheel shaft in case of mechanical contact/blockage - careful “two step forward, one step back” approach with analysis of motor currents and flat field images - so far, so good: verified normal motion over 9/10 of a full turn - side benefit: early measurement of DQE (and more….)

NICMOS dark current (C. Xu) -preliminary measurements indicate that dark current is nominal, i.e. close to Cycle 7 - “bump” is NOT observed Mean: e - /s Mean: e - /s Mean: e - /s

Then… (1998, T=62 K) Now… (2002, T= 77K) The first flat field images NIC1 NIC2 NIC3

DQE – comparison with expectations

Serendipitous image of a crowded star field Camera 2 in H-band (F160W) FWHM: 2.17 pixels (0.163“) (very close to nominal!) (…taken out from electronic distribution as requested by HST project…)

First assessment of image quality: (G. Schneider) -VERY close to nominal focus - some coma, to be corrected with tilt adjustment of PAM (in time for ERO observations) 1997 PAM tilt grid (NIC1, F095N) Mean PSF from 2002 stellar field (NIC1, F095N)

4/19 Fri109NICMOS restarted, Ne-loop control continues 4/22 Mon112Change to mounting cup control 4/23 Tue113Return to Ne control, Filter wheel test begins 4/26 Fri116Increase control temperature to allow for seasonal margins +2 K 4/29 Mon119Begin darks every 3 rd orbit 4/30 Tue120DQE test visit 1; Control temp +0.5 K 5/02 Thu122DQE test visit 2; Control temp –1.0 K 5/03 Fri123Filter wheel test complete; Focus sweep, FOM test, Transfer function test 5/04 Sat124DQE test visit 3; Control temp +0.5 K (TBD) 5/06 Mon126DQE test visit 4; Stop darks 5/08 Thu129Final temperature set point (TBD) 5/10 Sat131EROs begin, flats, thermal background 5/16 Fri137Final focus update, GO science enabled, remaining SMOV begins NICMOS SMOV: early activities timeline

Torsten Böker TIPS May 2, 2002 Summary - NICMOS has survived its 28 month hiatus without any significant degradation - performance is nominal so far - GO science will be enabled within 2 weeks