Next Generation X-ray Telescope:
Science and Possible Instrumentation
with Grazing Incidence
Photon-Counting Imager
Taro Sakao
ISAS/JAXAandThe NGXT sub-WG

Grazing Incidence Imager•! Much of the sub-WG discussion on GI haveconcentrated on photon-counting-type imager.
–! NI discussion made by Shimojo-san.
–! No advantage present for photon-counting
NI imager because of poor energy resolutionof Si detectors for EUV wavelengths.
!Spectroscopic investigation of hot plasmas
can only be performed by GI.
–! Photon-integration-type GI (direct extention ofYohkoh/SXT and Hinode/XRT) yet to be investigatedin great detail.

!"#$%&''()*X-ray Spectra from the Sun(Model Output with CHIANTI V5)98&'($!:;*+,-.($/(012)
72'2)&8$"28(341(5$64)

X-ray Spectra from the Sun(Model Output with CHIANTI V5)@B&01)0$EF?('.&-2)$1)$6>/?$!G2$H=252)I,24)-)0$,&H&F1815D*$

98&'($!:;*<=252)$724)-)0$1)$">/?$!@)?4A,1()5$1B&0($C4&815D*+,-.($/(012)

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6H(,5'2?,2H1,$EF?#$72'2)&8$"28(341(5$64)

X-ray Spectra from the Sun(Model Output with CHIANTI V5)@B&01)0$EF?('.&-2)$1)$6>/?$!G2$H=252)I,24)-)0$,&H&F1815D*$

98&'($!:;*

"! Emission Linesplus"! Continuum<=252)$724)-)0$1)$">/?$-! Thermal Bremsstrahlung!@)?4A,1()5$1B&0($C4&815D*
! Independent T info. from lines+,-.($/(012)
-! Non-Thermal Bremsstrahlung! Particle acceleration
JKL$
6H(,5'2?,2H1,$EF?#$72'2)&8$"28(341(5$64)

GI Telescope: Science Targets•! Soft X-ray corona in <1 – 10 keV... Discovery space with imaging spectroscopy•! Imaging spectroscopy of hot (>5 MK) plasmasin active regions–! Can never be investigated with EUV spectroscopy–! What is the highest temperature in ARs?
! Heating and thermal energy transport

+,-.($/(012)?$&)M$341(5$64)
•! NJ:$M(5('B1)&-2)
+,-.($/(012)$!OPPQ*

O$:R Q$:R OS$:R

341(5$/(012)$!OPPQ*

O$:R Q$:R OS$:R
(Brosius et al. 1996)

NJ:$&F2.($T$:R$)25$U)2V)#

"10=IW(BH('&54'($72BH2)()5?$$&,'2??$+,-.($/(012)?$&)M$341(5$64)
"25$H8&?B&?$V15=$$5(BH('&54'($TYQ;$:R$$!B2?5$81U(8D$ZOS$:R*$$
H'(?()5$)25$2)8D$1)$$+,-.($!>I'&D$F'10=5*$$/(012)?$F45$&8?2$1)$$
5=($341(5$64)$&)M$$ 13 Aug 08 06:15 UT)(&'$5=($H28(?[$(.()$$
M4'1)0$?28&'$B1)1B4B#$!$"2V$&'($5=(D$=(&5(M\$!!$"2V$&'($5=(D$B&1)5&1)(M\$!@?=1F&?=1$;SSX*!!$%=&5$NJ:\GI Telescope: Science Targets•! Flares–! Spectral features in the global magnetic structureassociated with reconnection!Investigation of shock–! Spatial distribution and temporal evolution of
non-thermal X-rays in the early phase of flares.
–! Fe line mapping for 20-30 MK plasmas•! Accelerated particles: Manifest themselves as
NT deviation from ambient thermal plasmas! Thermal + Non-thermal emission!<1 – 10 keV energy range essential

6=2,U$+,,(8('&-2)$
2]$J8(,5'2)?$1)$
72?B1,$<8&?B&?

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<2??1F181-(?`$<&'-,8($+,,(8('&-2)$615((Tsuneta et al., Ap.J. 1996)

(Tsuneta, Ap. J. 1997)

"

Non-Thermal Imaging
Larger image dynamic range with focusing
optics as comapred to Fourier synthesis typeimagery.
! Suited for observing NT X-rays in the corona!Acceleration
at the loop top

Acceleration
at the reconnection point!+?&1$(5$&8#$;SSP`$+H#$a#$bPT[$Ob;QIObQS*AR count spectrum
Extrapolation ofnon-thermal compo.

Angular Resolution (Pixel Size)
For photon counting: 5 arcsec
For photon integration:0.5 arcsec
Temporal Resolution
For photon counting: AR – 30 s, Flare – 10 s
For photon integration:TBD
J)('0D$/&)0(

1–10 keV, with sensitivity below
1 keV desired.

GI Telescope•! Employ CMOS imager sensor as the focal-plane array–! Sarnoff CMOS sensor consired to be the baseline device.

•! Use of “segment mirror”

Instrument Features (Preliminary)
•!
•!

Focal Length & Plate Scale : ~4 m and ~0.4”/8µm pixel, respectively
X-ray Mirror:
–!
–!

•!
•!

Grazing angle: 0.9 deg. (TBD; investigation ongoing between 0.45° and 1.8°)
Exposures:
–!
–!

•!

Attenuation for photon counting exposures
Analysis filters for photon integration exposures

Detector
–!
–!

•!

Either Photon Counting mode or Photon Integration mode
P-C to be performed with ROI size of ~256x256 pixels

Focal Plane Filters
–!
–!

•!

Walter-I like GI segment mirror (1/8 segment of a cylinder)
Coating with Ir mandatory to increase high-energy response;U$c$;U

Sarnoff CMOS image sensor (front illuminated) considered as the baseline
2k!2k (TBD) 8 µm pixel size

Frame Readout Rate
–!
–!

(#0#[$;Tbc;Tb

1000 fps for photon counting mode>=10-bits A/D conversion•! Data Output Rate:-! 110 Mbps for 512x512 ROI-! 6.9 Mbps for 128x128 ROI(Preliminary; no attempt in reduction)

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OSPrX

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W#$6&U&2$I$<7In@o6,1(),(o<(']2'B&),(#HH5$

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i/(.#$+jPresence of Partial-Opening in Each Pixel

T$u

O$u

S$u

Exploring Active Regions with NGXT: Science Cases+,-.($/(012)$NJ:

61B48&5(M$+/$?H(,5'4B$V15=$F&?(81)($Gn>W:0
4564'7'8999'(<=252)$@)5(0'&-2)
61<'(?(),($2'$&F?(),($$
2]$=10=('I5(BH('&54'($$H8&?B&?$!ZkT$:R*$1)$+/?$$)25$U)2V)$4)-8$)2V#

High-T lines to be clearly
imaged for the first timewith NGXT
Cannot beinvestigatedwith EUV line
spectroscopy.

+,-.($/(012)$()('0(-,?`$•!$"2V$1?$5=('B&8$()('0D$M1?5'1F45(M$1)$+/?\$•!$%=&5$1?$5=($B&c1B4B$5(BH('&54'($5=&5$$$$$&$)2)Iv&'1)0$+/$,&)$&m&1)\$

Even better
low-T diagnostics
expected with BIor front-thinned
FI detector.

Sample pixel binningfor NGXT imaging
spectroscopy.

!"#$%&$'()*+,-.(+.)/''
0%,1')1.,.&'+.2&3&$

Exploring Flares with NGXT: Science Cases
61B48&5(M$9^$?H(,5'4B$V15=$F&?(81)($Gn>W
456,'7'899'(9(Gn>W$&,5?$&?$$
F25=$5=('B&8$$&)M$)2)I5=('B&8$$
1B&0('#Emission lines provide high-T thermal
information while the continuum
provides both non-thermal and thermal
information.

%=('($&'($5=($'(,2))(,-2)d?=2,U$$?10)&54'(?$1)$5=($082F&8$B&0)(-,$
f(8M$,2)f04'&-2)\98&'($MD)&B1,?`$•!$@).(?-0&-2)$2)$()('0D$'(8(&?([$$$$$H&'-,8($&,,(8('&-2)[$&)M$?=2,U$$$$$]2'B&-2)#$•!$7'(&-2)$2]$?4H('I=25$H8&?B&?$$$$$&)M$5=(1'$?H&-&8$'(8&-2)?=1H$$$$$V15=$GIW$?24',(?#$\$•!$"2V$&'($)2)I5=('B&8$$$$$(8(,5'2)?$?H&-&88D$M1?5'1F45(M[$$$$$&)M$1)$V=&5$?H(,5'&[$M4'1)0$$$$5=($5'100('1)0$H=&?($2]$&$v&'(\$ Rich non-thermal emission•!$N2V)$52$V=&5$()('0D$1?$v&'($$ should be imaged in the$$$GIW$(B1??12)$H'(?()5\NGXT energy range.

Improvement indetector sensitivity
EventDetection
MethodLimit from charge spreadingand event detection methodSummary
Photon Counting GI X-ray Telescope:•! Photon-counting Mode:

Moderate angular resolution but should be able toprovide new information on:–! Physics of flares–! Thermal distribution across ARs#Spectroscopic imaging observations of the hotcorona in soft X-rays•! Photon-Integration Mode:–! Imaging of the hot (>~1 MK) plasma with thehighest angular resolution (0.5”) as GI–! Temperature diagnostic with filter-ratio–! Context information for photon-counting data