Superconducting Detectors for X-ray Science. Antonino Miceli August 2, 2012

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1 Superconducting Detectors for X-ray Science Antonino Miceli August 2, 2012

2 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

3 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

4 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. NRIXS Huotari et al RIXS Glatzel et al

5 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 Observables. ΔL s Mul'plexing: Lithographically vary geometric inductance/ resonant frequency ΔR s 1024 pixels demonstrated in 2011 (Ben Mazin et al) People are contempla<ng 10k pixels now Limited by room temperature electronics

6 Argonne for synchrotrons The goal is energy resolu=on < 10eV with good count rate capabili=es (> 100kcps) Three Main Aspects: 1. Device Fabrica'on Fabrica=on is completely in- house Rela=vely simple pa_erning of metal (deposi=on, photolithography, etching) Film quality is very important! Ini=ally aim a simple device, then progress to more complex designs (e.g., membrane- suspended) Dedicated deposi=on system being commissioned. 2. Cryogenics and Device Characteriza'on We are mostly limited by how fast we can test devices. 3. Readout electronics Ini=ally the analog readout for characteriza=on. Digital FPGA- based array readout in the near future.

7 Anatomy of an MKID Our work (one design) 1 pixel Inductor/Absorber 15 pixels Simula=on Capacitor 1 micron WSi 2 (XSD) 2 mm First x- ray pulses at APS in January 2012! Fe- 55 and Cd- 109

8 From an empty lab. Cryostat Cryostat Cryogen Free ADR T = 100 mk for 2 days 3-4 hour recycle =me Microwave Electronics Vector Network Analyzer IQ mixing Control & Data Analysis Sodware Be window Microwave Electronics

9 From optics to detectors Tungsten Silicide MKIDs We have been searching for dense materials for x- rays. WSi x is a material with low T c, high kine'c inductance frac'on and good quality factors. T Cecil, et al., Applied Physics LeJers, (2012)

10 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., ~ pixels) Silicon Bring deposi'on system up and running MKID SiN Membrane

11 People Antonino Miceli (XSD Staff) (80%) (PI) Tom Cecil (XSD Staff) (80%) Orlando Quaranta (Post- doc) (100%) Lisa Gades (XSD Staff) (20%)

12 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.