XIS FM sensors cal. report

Hiroshi Nakajima

2004.3.16 XIS meeting@ISAS

CCD -90 deg. C was achievedwith BUS power supply of 4W

・ TEC hot side T is fixed to ~-40 deg. C・ Monitored the CCD T varying the SCL of TECfrom 110% to 40%

1.TEC cooling performance

As for S2 and S3,see the report of

Osaka Univ. on Web.(Almost the same result

was obtained.)

2. Energy resolution and Readout noise55Fe(5.89,6.49keV) MnKα 　

MainMnKβ 　Main

Si escape

Si Kα

constant

FM-S0 FM-S1 FM-S2 FM-S3

Resolution@5.9keV

(FWHM) eV

129.6 (±0.6)

136.0 (±0.4)

129.4 (±0.7)

131.0 (±1.1)

Readout noise (RMS) electrons

2.0(±0.1)

3.3 (±0.2)

1.8 (±0.1)

2.3 (±0.1)

Expected resolution and noise level for every sensor

HOC

active

3.How to measure and correct CTI with CI

• We plot the readout PH of injected charge for each column. (This should contain the info. of parallel CTI.)

• Then compensate the charge for the dependency with column. (This correct the parallel CTI.)

X (pixel)

PH

X (pixel)

PH

•We intended to adopt the following method:

•With any method, we must confirm the stabilityof the amount of injected charge first of all.

4.Amount of charge in the specific pixel

Injected Charge:4.6keV,FWHM85eV for X-ray

~70% of ⇒Ti(4.5keV,FWHM123eV)

Injected charge

cou

nts

PHDistribution of injected charge to specific pixel （ 350frames ）

PH

X (pixel)

5.Stability of the amount of injected charge•We took dark image with CI onat 3/9 and 3/10 with FM-S3 (100 frames each).

Red:03/09Green:03/10

Possible correlation was seen

6.Column dependency of the charge

Amount of injected charge

Correlation between inj. charge and 55Fe

5ch

Amount of charge of 55Fe event

5ch

•Is the dispersion of injected charge between pixels due to CTI?•If so, 55Fe events show the same pattern.

Dispersion of X-ray events is smaller⇒we cannot conclude the correlationCTI between columns?…NO

fit: slope 0.04±0.02

PH

X (pixel)

PH

X (pixel)

55F

e

Inj. charge

Parallel CTI:1-2×10-6

=2-3ch/1024 trans.

7.Causes of column-dependent dispersion

• Disperse when injected from input diode?NO. amount of charge is stable in the specific pixel.⇒

• CTI in the serial register?NO. it should result in no dispersion.⇒

• Charge were lossed when transferred from serial register to IA?

This result will be the referencefor further calibration

Do we need to adopt other method tocorrect CTI as suggested by Steve-san?

•Inject 2 or more rows varying the spacing•Make charge various up and down

8.Summary

1. TEC successfully cooled CCDto ~-90 deg. C with power supply of ~4W

2. ΔE(FWHM) ~130-135eVRead out noise ~2-3 electronsfor all FM sensors

3. We cannot see the correlation betweenthe column dependency of injected charge and 55Fe events.Do we need other method for CTIcorrection?

1.TEC cooling performance

1. CTI by 55Fe data

Mean of the data for 0<X<7

Mean of the data for 248<X<255

Y (pixel)

PH

Parallel CTI:2.04×10-6

Parallel CTI:1.06×10-6