1

Camera debrief

Christopher StubbsDM All-Hands meeting

12 February 2015

2

1/3 RTM test

O’Connor, Kuczewski, Juramy, Haupt2/6/2015

3

Setup• 3 CCD250 prototype sensors on

CeSiC raft baseplate• One REB2 + DREB1 in vertical slice

(TS7) cryostat– 6X ASPIC3– 6X CABAC0

• REC mockup• read_ccd_480kHz.ssf sequencer

file: – 480kpix/s, no serials during

exposure, fast clear once on startup• Clock and bias settings:

– OD/RD/GD 28/18/28– Clocks +10/0, RG

• Setpoints:– RSA -100C– coldplate -10C

4

Flatfields ~170kADU

5

Image

6

PTC with polyfit(2)

mean of sum image ADU

Var

of

diff

imag

e A

DU

2

Note: ½ of channels have different gain setting resistors populated on REB

7

Gains

0.0 0.5 1.0 1.5 2.0

0.5

00

.55

0.6

00

.65

0.7

00

.75

0.8

0

chip

ga

in, e

-/A

DU

5 10 15

0.5

00

.55

0.6

00

.65

0.7

00

.75

0.8

0

chang

ain

, e-/

AD

U

Black – chipARed – chipBGreen - chipC

Black – topRed – bot

A B C

Note: CCD B has lower sensitivity than A or C due to AR coating difference (see slide 8)Note: ½ of channels have different gain setting resistors populated on REB

8

480kpix/s gain

0 10 20 30 40

0.5

50

.60

0.6

50

.70

Index

ga

in

CCD A CCD B CCD C

9

CCD C

CCD B

CCD A

10

480kpix/s noise

0 5 10 15

56

78

9

segment

no

ise

, e-

Black – chipARed – chipBGreen - chipC

channel

11

Mean vs. exptime

Linearity

Note: ½ of channels have different gain setting resistors populated on REBCCD A one ASPIC gain setting is 2X

12

“Sampling scope” diagnostic mode• Using normal video channel

ADCs, can measure repetitive waveforms by delaying the timing of the convert pulse on successive pixel cycles.

• LPNHE-provided firmware performs this automatically

• Can set ASPIC into “transparent “ mode to visualize CCD OS waveform

• Equivalent to an 18-bit, 100MHz sampling oscilloscope

vo

ltag

e

reset feedthru

reset level

video level

ramp down

ramp up

ASPIC reset

13

Notes• REB-to-REC mounting is overconstrained

– Many REB solderjoint problems

• REB temperatures in ASPIC/CABAC/ADC region ≈Tcoldplate + 20C; DREB temperature ≈ 20C warmer than REB

• To do:– Install x-ray sources – REB temperature study– Optimize timing at 550kpix/s using sampling scope mode– Measure crosstalk matrix– Exercise:

• CCD RTD temperature sensor• Heater control• Diagnostic ADC

– Proceed to Phase 5 (full RTM)

stage on-project off-project coord & sign-off

anomaly identification sensor team

SAWG camera scientistSAWG lead

characterization & parameterization

DESC labs SAWG lead

implementation in phosim

phosim team

validation of simulations

DESC, SAWG SAWG lead, PST, TC

compensation algorithm – image and/or catalog level

DM DESC WG’s, other LSST WG’s

PST, science teams

compensation alg. assessment & validation

DM, PST DESC WG’s PST, science teams

quantify residuals and systematic error

DM, PST DESC WG’s PST, science teams

Wed

nesd

ay

Tue

sday

15

BACKUP

16

Gain and noise comparison

0 10 20 30 40

0.5

00

.55

0.6

00

.65

0.7

00

.75

0.8

0

Index

ga

in

0 10 20 30 405

67

89

Index

no

ie

Black – POCBlue - JK

17

ratios

0 10 20 30 40

0.9

00

.95

1.0

01

.05

1.1

0

Index

jk[,

3]/g

ain

0 10 20 30 400

.00

.51

.01

.52

.0

Index

jk[,

4]/n

oie

18

REB2

A

B

CDREB1

-100C

-10C ColdPlate