Superconducting Cold-Electron Bolometer with SIS´ and Josephson Tunnel Junctions and JFET Readout Leonid Kuzmin Chalmers University of Technology, MC2 Bolometer Group LTD12, Paris Through the thorns to the stars! Igenom törnen mot stjärnorna! Через тернии к звездам! In cooperation with: Rome University (Paolo de Bernardis) and Cardiff University (Phillip Mauskopf)

Cosmic Microwave Background (CMB) radiation

BOOMERANG-3 - balloon telescope Measurements of the CMB Polarization CEB for 350 GHz, 90 channels, CHALMERS is the only provider! CEB for 150 GHz, 9 channels (old JPL bolometers available) The BOOMERANG2 telescope hanging from the NASA Delta launch vehicle, ready for launch. January 2003

The He3 refrigerator for BOOMERANG detectors from the temperature of at 0.3 K Focal plane

Balloon telescope BOOMERANG Channel II: 350 GHz Background Power load : P 0 = 5 pW Photon noise: Total NEP of bolometer should be less than photon noise: NEPtot < NEPphot. Polarization rezolution > 40dB Launch From Paolo de Bernardis, March 29, 2007, Rome

Cold-Electron Bolometer (CEB) with Capacitive Coupling to the Antenna Kuzmin – ISSTT-98

Noise characterization of the CEB I. Agulo, L. Kuzmin, and M. Tarasov Room T amplifier - AD743 Power load – 20 fW

Optimal CEB with an SIN Tunnel Junction and Andreev SN Contact Kuzmin – ISSTT, Paris 2006 SN-NIS

Superconducting Cold-Electron Bolometer (SCEB) with SIS´ and Josephson Tunnel Junctions and JFET readout for BOOMERanG Balloon Telescope SIS´-S´IS

4 SCEBs with JFET readout for each polarization component - Circle waveguide is coupled to 4 coplanar lines - 2 opposite coplanar lines are combined for one readout for polarization measurements HF part is similar to “SCEB for OLIMPO” L. Kuzmin, P. Mauskopf and D. Golubev, EUCAS-2005

Cold-Electron Bolometer Noise NEP e-ph 2 = 10 k B  V (T ph 6 + T e 6 ) (Jochum et al. – 1998)

JFET amplifier noise We need matching with We need

NEP for 4 SCEBs with JFET readout NEP tot < NEP phot S=1  m2 R=0.5 kOhm, Vol=0.02  m3, T=300 mK I JFET =10 fA/Hz 1/2 V JFET =3 nV/Hz 1/2 Power load = GHz SIS´: Tc1=1.2K, Tc2=0.5K

350 GHz. NEP for 4 SCEBs with JFET readout NEPtot < NEPphot S=1  m2 R=0.5 kOhm, Vol=0.02  m3, T=300 mK I JFET =10 fA/Hz 1/2 V JFET =3 nV/Hz 1/2 Power load = 5 pW SIS´: Tc1=1.2K, Tc2=0.5K

Dependence of NEP components on volume of the superconducting absorber Total NEP < NEPphot S=1  m2 R=0.5 kOhm, Vol=( )  m 3, T=300 mK I JFET =10 fA/Hz 1/2 V JFET =3 nV/Hz 1/2 350 GHz. Power load = 5 pW

Cascade Quasiparticle Amplifier L. Kuzmin, Physica C. 372, 457 (2002)

Superconducting Cold-Electron Bolometer with SIS´ & Josephson Junctions for BOOMERanG Leonid Kuzmin, Paola Feodino, Katarina Olsson, Michael Tarasov, Nassar Abusitta, Ernst Otto, Phillip Mauskopf, Paolo de Bernardis LTD12, Paris Chalmers University, Rome University and Cardiff University Planar Si substrate

Conclusions New generation of detectors is needed to measure polarization of Cosmic Microwave Background BOOMERanG: 350 GHz, P 0 =10pW, JFET readout, photon noise sensitivity & high polarization rezolution Superconducting Cold-Electron Bolometer with SIS´ and Josephson junctions – the most effective and reliable decision