XEUS Cryogenic Instrument 26 - 27 October 2004

Cryogenic X-ray sensor development in US, Europe and Japan

Micro-calorimeters

• Doped - thermistors

Astro-E2 6 x 6 pixel array (GSFC/Wisconsin/JAXA)

Single pixel work also at Harvard – Smithsonian in collaboration with INAF, Palermo

Sub-mm and IR-bolometers (spiderweb) at JPL/Caltech, MPIfR, Bonn and CEA/Saclay (CEA also arrays)

- doped-Si or doped-Ge thermometers - HgTe or Sn absorbers - Typical pixels of 0.25 – 1mm square - J-FET read-out (no multiplexing)/MOSFET’s - E ≥ 4 eV @ 1 – 6 keV with τ ≈ 1 – 10 ms

Pro: proven technology

Con: difficulty making large arrays due to fabrication by hand and absence of low-noise multiplexed read-out; limitations in speed and resolution

XEUS Cryogenic Instrument 26 - 27 October 2004

Cryogenic X-ray sensor development in US, Europe and Japan

Micro-calorimeters– Phase-transition thermometers (TES)

• X-Ray applicationsCon-X (arrays/TDM/cryogenics) preparations – NIST/GSFC/WisconsinTES gamma-ray sensors (single pixels) – LLNLXEUS (arrays/FDM) preparations - SRON/MESA/VTTTES single X-ray pixel development – INFN, GenuaNEXT/DIOS/XEUS (arrays/FDM) - ISAS/Metropolitan/Waseda

• Sub-mm applicationsScuba II sub-mm 10.000 pixel array (2005) – NIST/ATCGround-based sub-mm arrays with TDM – GSFC/NISTSub-mm bolometer arrays/filters and FDM - UCBerkeley Stanford Optical TES

Sub-mm bolometer arrays and read-out - MPIfR, Bonn/JENA Sub-mm TES array/filter development - Cardiff/Cambridge/SRON

XEUS Cryogenic Instrument 26 - 27 October 2004

Cryogenic X-ray sensor development in US, Europe and JapanMicro-calorimeters

– Phase-transition thermometers (TES)Characteristics

• MoCu, TiAu and IrAu TES• Bi absorbers• Typical pixel size 250 x 250 μm2

• Array size up to 8 x 8 E > 2.8 eV @ 5.9 keV, τ ≈ 0.1 – 1 ms• SQUID amplifiers with TDM or FDM

Pro and Con’s

Pro: TES is maturing in the 2000 – 2010 timeframe, Large arrays possible from manufacturing and read-out point of view. Potential energy resolution improvement by factor 3:

)(34.0)(FWHM

keVEeVE SATCon: speed limited to about 0.1 ms, pixels larger than 0.5 mm difficult without loss of resolution

XEUS Cryogenic Instrument 26 - 27 October 2004

Cryogenic X-ray sensor development in US, Europe and Japan

Micro-calorimeters:– Magnetic calorimeters (single pixels so far)

Brown Univ/Heidelberg UnivNIST(recently also GSFC started)CharacteristicsAu:Er thermometersMetallic (Au) absorbersE = 3.4 eV @ 5.9 keV, τ = 60 ms, T = 35 mK, B = 3mT

Pro and Cons:Prospect for ≈ 1 eV energy resolution with large absorbers

Cons:Sensor speed limited to 0.1 – 1 ms by large heat capacity and e-

ph coupling to the bath

XEUS Cryogenic Instrument 26 - 27 October 2004

Cryogenic X-ray sensor development in US, Europe and Japan

Non-equilibrium sensors:– Superconductive tunnel junctions

USA - LLNL (single pixels); Yale (1-D structures)Europe - ESTEC for optical and X-ray applications (single pixels, 1-D/2-D structures, and arrays)

PSI, Villigen; TUM, Munich; CNR, NapoliJAPAN - IAST,Tsukuba; Riken, Tokio

Characteristics• Ta/AlO/Ta structures most successful• Arrays made up to 18 x 32 E ≈ 2 eV @ 1 keV and 6 eV @ 6 keV obtained• Typical 25 – 50 micron pixels• Τ ≈ 10 μs

Pros:Fast response time and good energy resolution for E < 2 keV

Con’s:Difficulty to make large pixels while retaining energy resolution and speedRead-out of large arrays difficult due to magnetic field requirement and lack

of adequate multiplexing