1

LBNL Hardware R&D Effort Towards CMB S-4

LBNL CMB Group

March 09th 2016

3/9/2016

Team

3/9/2016 2

Darcy BarronChris BebekAri CukiermanMaurice GarciaJohn GrohCharlie HillSteve HollandBill HolzapfelOliver JeongRhonda Witharm

Akito KusakaAdrian LeeMia NakajimaNick PalaioNatalie RoeKaja RotermundIan ShirleyLeo SteinmetzAritoki SuzukiCo Tran

LBNL CMB Hardware R&D Activity

3

Expanding frequency coverage efficientlyQ: How to guard against foreground?

• Multi-chroic lenslet coupled sinuous antenna • Mapping speed doesn’t drop off quickly, 3 color still gives boost in mapping speed

150

22095

Fλ

Norm

aliz

ed M

appin

g S

peed

Halverson 2005

Diplexer

Triplexer

3/9/2016

150 GHz: Angular responseSpectral responseSi lenslet coupled sinuous antenna

5.346 mm

• Covers multiple frequency bands with one pixel

• Efficient pixel design for CMB observation and foreground monitoring

• POLARBEAR-2/Simons Array (2-colors) and SPT-3G (3-colors)

Lenslet Coupled Multi-Chroic Pixel

1.5 mm

Detector wafer in an invar holder

130 mm

POLARBEAR-2 Detector ModuleSinuous antenna and TES bolometers

43/9/2016

LBNL CMB Hardware R&D Activity Cont.

5

Enabling a Factor 10-100 Increase in Detector CountQ: How to fabricate and read-out 500,000+ detectors in reasonable time/cost?

• Detector fabrication with industry• Automatic probe station• Automatic wire bonding • Quick application of anti-reflection coating on refractive optics with thermal spray• Monolithic superconducting resonator for read-out• High frequency (~50 MHz) multiplexing• Integration of read-out resonator and detector

Industry, Automation, Integration

Reducing 1/f noise, Systematics controlQ: How to reach low ell? How to reduce systematics?

• Continuously rotating cryogenic half-wave plate

3/9/2016

Industry Detector Fabrication

6

TES bolometer islandProto-type die from 6” wafer

3/9/2016

• 500,000 detector more than 1,000 wafers

• Industry fabrication to mass fabricate detectors LBNL CCD group’s experience with DALSA

• Fabricated simplified version of CMB detector• Optically active antenna coupled TES bolometer• Integrated inductors and capacitors within die space

20 mm

Chip overview

Sinuous feed

Nb

Pd

AlNitride leg

TES Bolo

ID capacitor50 um

25 um

400 um

CMB Detector R&D at LBNL

• Installing micro fabrication equipment for detector R&D

73/9/2016

Automated Quality Control and Packaging

• Automation faster, consistent quality, tighter packing density• Developed automatic proving station to check DC connectivity of detector wafer• Developed automatic wire bond to make 100 um pitch wire bond

8

Automatic probing station Automatic wire bond

3/9/2016

Scalable Anti-Reflection Coating

9

Thermal spray coating• Melt and accelerate dielectric powder with hot plasma• Tune dielectric constant by controlling filling factor• Coat over large area (reimaging lens) or small structure (lenslets)

Thermal sprayed alumina puck

Thermal sprayed silicon lenslets

50 mm

6 mm

Transmission through 2-layer thermal spray + Teflon coating on alumina

Dielectric constanttunability

3/9/2016

M&M Thermal Spray Coating Process

10

• Used same coating method as M&M candy• Coating uniformity, 0.5 mil

M&M coaing with mm scale ruler How M&M chocolates are coated Thermal spraying ceramic powder to alumina sphere

Coated alumina sphere Grinded to hemisphere Zoom in at coating

3/9/2016

6 mm

Readout Electronics – Superconducting Resonators

• Monolithic lithographed superconducting resonators for fMux readout• Demonstrated high yield. (MSL Class 10~100)• Automatic wire bonder for wire bonding• Demonstrating mass production capability with S-3 experiments (PB/SA & SPT3G)

POLARBEAR/ Simons Array (x40 mux) SPT-3G (x68 mux)

Network Analysis of Superconducting Resonators

113/9/2016

50 mm

High Frequency LC, LC & Detector Integration

12

• Pushing frequency MUX• Higher frequency resonators to increase total readout bandwidth

• Fabricated resonators ~50 MHz smaller size• Integrate readout resonators and detectors on same chip

Industry fabricated chip LC resonators on chip 2 um line, 2 um gap lines

3/9/2016

1.5 mm

20 mm

YBCO ring

Prototype fabrication & evaluationConcept design

Sapphire HWP

Magnetic drive

High-Tc superconducting bearing

• Established design concept through a small prototype

• Will fabricate full-scale system and test/evaluate with Simons Array as a test platform

• LBNL’s expertize in high-Tc SC (ATAP) and cryogenic engineering.

Cryogenic Half-Wave Plate

133/9/2016