Status report of the Hard X-ray Detector

Shinya Yamada, RIKEN on behalf of the HXD team

The 4th Suzaku Conference 2011 @SLAC

2004

Wide-band Spectra of Suzaku

2

AXP 0142+61 (NS)

Cyg X-1 (BH)

Energy (keV)

10 1

0.1

0.01

1 10 100

GC

vFv

(from Max’s presen)

XIS (CCD) HXD-PIN HXD-GSO

Overview of Hard X-ray Detector (HXD)

3

HXD-PIN (64) 10~60 keV

HXD-GSO (16) 50~300 keV

HXD-WAM (20) Ohno’s talk

X-ray

Overview of Hard X-ray Detector (HXD)

4

W0 HXD-PIN (64) 10~60 keV

HXD-GSO (16) 50~300 keV

HXD-WAM (20) Ohno’s talk

Overview of Hard X-ray Detector (HXD)

5

HXD-PIN 10~60 keV

HXD-GSO 50~300 keV

HXD-WAM

W00

Overview of Hard X-ray Detector (HXD)

6

HXD-PIN 10~60 keV

HXD-GSO 50~300 keV

HXD-WAM

W00p0

Status of the HXD u  Overview ~ all 116 sensors working well ~

u  PIN (64 units) u  taking measures for increase in thermal noise.

u  GSO (16 units) u  energy scale improved

u  gain history updated u  responses updated

u  detailed analysis of Crab spectra (Kozu’s poster)

u  BGO (16 units) u  working properly.

u  WAM(20) u working properly (Ohno’s talk)

7

Operations for HXD since June of 2009 u  2009, Sep. 13

u  Count rate of HXD W01p3 suddenly flares up. u  　calmed down spontaneously.

u  2010, Jan. 16 u  need to reduce FIFO-full and buffer flush in W3

u  W3 PIN analog LD was increased. u  PIN response epoch 7

u  need to reduce buffer flush in W21p1 u  in-orbit software LD was increased.

u  2010, Feb. 2 u  need to reduce FIFO-full and buffer flush in W2

u  W2 PIN analog LD was increased. u  PIN response epoch 8

u  2010, Apr. 3 u  need to reduce FIFO-full and buffer flush in W0

u  W0 PIN analog LD was increased. u  PIN response epoch 9

u  2010, Dec. 16 u  LD cut in on-board DE (CPU) were increased for most of PIN.

u  no effects for analysis

u  2011, May 25 u  Need to reduce FIFO-full and buffer flush in W1 and W3

u  W1 and W3 PIN analog LD was increased. u  PIN response epoch 11

8

Calibration of HXD-PIN

Sho Nishino (Hiroshima U.)+, 2010, SPIE

9

Long-term count rates trend of 4 PINs in W32

10

Analog-LD ↓ was raised.

2005 2011

INPUT: Sho Nishino @Hiroshima U.

Long-term spectral variation of W22P2

11 15 keV 7.5 keV

Thermal noise increases with time.

Temperature-sorted spectra of W32P1

12 15 keV 7.5 keV

Higher temperature, larger thermal noise.

13

LD distribution for 64 PINs INPUT: Sho Nishino @Hiroshima U.

LD is increasing..

Gain & Energy resolution of 64 PINs

14

ΔE @Gd-K 43 keV

PI @Gd-K 43 keV

~ 2005

~ 2010

3.8 keV ~2005

4.7 keV ~ 2010

Gain shift << 1%

15

The Leakage Currents of PIN INPUT: Sho Nishino @Hiroshima U.

Sugizaki+97’ Sugiho Master thesis

Mostly electronics unchanged

Leak current

ΔE increases explained by increase of leak current.

Calibration of HXD-GSO

Yamada, Makishima+, 2011, PASJ

16

Before calibration…

17

Kokubun+ 2007

A single powelaw fit… something wrong but what? We’d been struggling for studying its cause for more then 2 years since the launch….

The Background Spectrum of HXD-GSO

18

e+e- 511 keV

α decay natural 152Gd ~ 350 keV

IC 151m Eu ~ 200 keV?

EC 153Gd ~ 150 keV?

EC 151Gd ~ 70 keV?

Kokubun+ 2007

(1) The non-linear effect of light yields in GSO

19 19

e - response (Uchiyama 1998)

Photon response (Kitaguchi 2006)

Annihilation line à  Single γ 511 keV Activation lines à Multiple γ , e -

“70 keV” lowered by ~6 %, “150 keV” by ~ 5%, “196 keV” by ~ 3 %

151Gd 20 keV

151Eu

EC Ex). 70 keV

Eu K binding E ~ 50 keV γ decay

Several e- or γ reduces light yeilds, considering all decay probability, The correct energy are,

Fluorescence or Auger e-

gamma-ray or IC e-

E vs. light yeilds relation in GSO

Num

ber o

f Wel

l uni

ts

ADC channel70 80 90

0

2

4

6

8

(2) The Analog Offset (so-called pedestal) Shift

20

Laboratory Power June, 2004

Satellite Power, Aug. 2004

Satellite Power Aug. 2006 （In orbit）

After using the satellite power, the analog offset changed by ~ 8 ch lower cf. 8 ch << 4096 ch (the maximum ADC channels of GSO)

pedestal

Agreement with On-Ground measurements

21 100 200 300 500500.9

1.0

1.0

1.1

1.0

1.1

1000

2000

200

500

1.1

Ratio

Ratio

Ratio

H - !

H (A

DC ch

anne

l)

Q (channel)

on ground

(1) inc. light yeild

(2) inc. analog offset Energy (keV)

GSO

bra

nch

wid

th (k

eV)

30 50 200100 500

2

5

10

in orbit (new) on ground

simulation

in orbit (old)

In-orbit data agrees with both simulation and on-ground data. (Yamada, Makishima+11, PASJ)

in orbit (old)

Input charge vs. ADC plot

Both agrees.

Improvement on reproducing gain history

22

The remote pass from SAA The 1st SAA pass The 5th SAA pass

Gain recovery depending on the order of SAA pass will enable us to improve a modeling of gain history.

1 orbit

(~15 orbits/day)

Crab Nebula

Kozu’s poster, and her paper is in progress.

23

10 3

0.01

0.1

1

norm

aliz

ed c

ount

s s

keV

10020 50 2000.5

1

1.5

ratio

Energy (keV)

HXD Spectra of the Crab Nebula

24 Kouzu’s poster

Now that the best-fit parameters with broken powerwlaw Γ1 ~ 2.08-2.12, Eb ~ 110-160, Γ2 ~ 2.2-2.3

Ratio

Counts/ s/keV

500

The ratio to a single powerlaw with Γ = 2.1

Long-term HXD flux trend of the Crab Nebula

25

HXD  

12-­50  keV  (erg/s/cm2)  

50-­100  keV  (erg/s/cm2)  

100-­500  keV  (cnt/s  stat&sys  err)  

2005 2010

(Kouzu’s poster)

Aug 27, 2008

Energy (keV)

cnt/s

/cm

2 /keV

20 50 100 500

1

10-2

10-4

1 0.5

1.5

ratio

Ratio to best fit power law

Aug 27, 2008

Energy (keV)

cnt/s

/cm

2 /keV

20 50 100 500

1

10-2

10-4

1 0.5

1.5

ratio

Ratio to best fit power law

The HXD fluxes follows with those of other missions.

Long-term spectral change of Crab Nelula

26

1.5  

1.0  

20   50   100   200  

Energy  (keV)  

ratio  

(Aug.  08:  Bright)  /  (Feb.  10:Dim)  

0.5  

500  

PIN   GSO  

Best  fit  constant  

More significant change in higher energy E > 200 keV

(Kouzu’s poster)

Summary

u  HXD on board Suzaku has realized the wide-band and high-quality observation without any problems.

u  Adequate operation for LD of HXD-PIN have been performed, so that all units can be properly analyzed.

u  The new HXD-GSO energy scale are obtained by utilizing the calculation of light yield and the shift of an analog offset. Corresponding responses and software have been released.

u  Now that we can quantify not only the detailed shape of the Crab Nebula, but also its variation with time.

27

28

Thank you (photo; 2004/04/30 HXD completed)

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29

Wide-Band Spectra of Suzaku XIS (CCD) HXD-PIN HXD-GSO

Cra

b R

atio

Ada+ (2008)

Response Simulator includes Light yields

30

Incident X-ray into HXD

Calculate E deposited in HXD

Accumulate deposited E ≠ Light Yield

SimHXD : Framework of Response Generator ( Terada et al. 2005 )

Calculate E of secondary e- or γ in GSO 　

Convert each E into light yield by using E vs. LY. relation in GSO

Accumulate Light Yields

　New GSO response have been released since April of 2010

new previous

Geant 4 ANL