Superconducting Detectors for X-ray Science...The leaders of the field are in the US! !...
Transcript of Superconducting Detectors for X-ray Science...The leaders of the field are in the US! !...
Superconducting Detectors for X-ray
Science
Antonino Miceli August 2, 2012
The leaders of the field are in the US!
§ Transi'on Edge Sensors à Joel Ullom et al
§ Microwave Kine'c Inductance Detectors à Ben Mazin et al
Superconductors Detectors for X-ray Detector R&D
§ Energy dispersive semiconductor detectors have almost reached their theore'cal limits – e.g., Silicon Dri7 Diodes have energy resolu=on ~ 150 eV at 6 keV
§ Limited R&D on spectroscopic detectors – Only effort is Silicon array detector of Peter Siddons (BNL) and Chris Ryan
(Australia) • Using silicon arrays to achieve large collec=on solid angles for micro-‐probe XRF
experiments.
– Can impact x-‐ray spectroscopy and diffrac=on.
§ Leverages local facili'es and exis'ng projects. – Argonne’s Nanocenter (CNM) for device fabrica=on – Many groups with thin film deposi=on experience – APS RF group (3D EM simula=on, Low-‐level RF electronics)
– Superconduc=ng Transi=on Edge Sensors for UChicago’s SPTpol
Applications for superconducting x-ray detectors?
§ X-‐ray Inelas'c ScaJering – “Photon-‐in Photon-‐out X-‐ray Spectroscopy” – Access wide range of excita=ons.
• Compton Sca_ering (e.g., measure bulk Fermi surface) • EXAFS of low-‐Z materials with hard x-‐rays • RIXS/XANES (remove pre-‐edge features using RIXS) • X-‐ray Emission Spectroscopy (XES)
– Superconduc=ng detectors allows broadband and efficient measurement compared to crystal analyzers (i.e., SBCAs).
• Possibly need high-‐mosaic crystal pre-‐filter to suppress elas=c peak (e.g., logarithmic spiral filters, Bunker et al)
§ Energy Dispersive XRD (white beam diffrac'on) – Versus angle-‐dispersive diffrac=on
• Using monochroma=c incoming beam and area detector
– Complex sample environments for in-‐situ studies (e.g., high-‐pressure cells, ba_ery research)
§ Need to perform proof-‐of-‐principle experiments and engage beamline scien'sts.
RIXS
Glatzel et al
NRIXS
Huotari et al
Microwave Kinetic Inductance Detectors § Quasipar'cle (or ΔT) generated by x-‐ray
causes an inductance increase (i.e., “kine'c inductance”) – Measure inductance change in a LC resona'ng
circuit
Mul'plexing: Lithographically vary geometric inductance/resonant frequency…
ΔLs
ΔRs
Observables….
Ø 1024 pixels demonstrated in 2011 (Ben Mazin et al) Ø People are contempla<ng 10k pixels now
• Limited by room temperature electronics
MKIDs @ Argonne for synchrotrons § The goal is energy resolu=on < 10eV with good count rate capabili=es (>
100kcps) § Three Main Aspects:
1. Device Fabrica'on Ø Fabrica=on is completely in-‐house Ø Rela=vely “simple”… pa_erning of metal (deposi=on, photolithography, etching)
Ø Film quality is very important! Ø Ini=ally aim a simple device, then progress to more complex designs (e.g., membrane-‐
suspended) Ø Dedicated deposi=on system being commissioned.
2. Cryogenics and Device Characteriza'on Ø We are mostly limited by how fast we can test devices.
3. Readout electronics Ø Ini=ally the analog readout for characteriza=on. Ø Digital FPGA-‐based array readout in the near future.
Anatomy of an MKID – Our work (one design)
1 pixel
15 pixels 2 mm
Ø First x-‐ray pulses at APS in January 2012!
Ø Fe-‐55 and Cd-‐109
1 micron WSi2 (XSD)
Inductor/Absorber
Capacitor Simula=on
From an empty lab….
Be window
Cryostat
Microwave Electronics
§ Cryostat Ø Cryogen Free ADR Ø T = 100 mK for 2 days Ø 3-‐4 hour recycle =me
§ Microwave Electronics § Vector Network Analyzer § IQ mixing
§ Control & Data Analysis Sodware
From optics to detectors… Tungsten Silicide MKIDs
§ We have been searching for dense materials for x-‐rays. § WSix is a material with low Tc, high kine'c inductance frac'on and good quality factors.
T Cecil, et al., Applied Physics LeJers, (2012)
Near-Term Activities
§ Focused on itera'ng on x-‐ray pixel designs – Detector Design Goals
• Energy resolu=on – 1 year goal < 60eV (Al/Ta CPW geometry) – 2 year goal < 30eV – 3 year goal < 5eV (SiN membrane suspended)
• Count rate capabili=es (> 100kcps) (i.e., ~200-‐500 pixels)
§ Bring deposi'on system up and running
SiN Membrane Silicon
MKID
People
§ Antonino Miceli (XSD Staff) (80%) (PI) § Tom Cecil (XSD Staff) (80%) § Orlando Quaranta (Post-‐doc) (100%) § Lisa Gades (XSD Staff) (20%)
Conclusions
§ Superconduc=ng detector development has started at the APS. – Tes=ng infrastructure (cryo, electronics, analysis so7ware) is complete. – Now focusing on device fabrica=on and itera=ng on designs
§ MKIDs are a path towards high count rates and higher solid angle coverage. – Has the poten=al to provide a very unique capability (detector/instrument). – Can impact x-‐ray spectroscopy and diffrac=on.
§ MKIDs are a rela=vely young technology and there is room for improvements.