---++ Detectors

• cryostat run 20100519
• POLARBEAR wafer KT7 is used
• Reconfigured (channel to channel correspondence is not right for now) :

Old KT7	New KT7
comb-SqCh-ch	comb-SqCh-ch
A-1-0	B-2-0
A-1-1	B-2-1
A-1-2	B-2-2
A-1-3	B-2-3
A-1-4	B-2-4
A-1-5	B-2-5
A-1-6	B-2-6
A-1-7	B-2-7
B-2-0	B-2-8
B-2-1	B-2-9
B-2-2	B-2-10
B-2-3	B-2-11
B-2-4	B-2-12
B-2-5	B-2-13
B-2-6	B-2-14
B-2-7	B-2-15
C-3-0	C-3-0
C-3-1	C-3-1
C-3-2	C-3-2
C-3-3	C-3-3
C-3-4	C-3-4
C-3-5	C-3-5
C-3-6	C-3-6
C-3-7	C-3-7
F-3-0	F-3-0
F-3-1	F-3-1
F-3-2	F-3-2
F-3-3	F-3-3
F-3-4	F-3-4
F-3-5	F-3-5
F-3-6	F-3-6
F-3-7	F-3-7
G-1-0	H-2-0
G-1-1	H-2-1
G-1-2	H-2-2
G-1-3	H-2-3
G-1-4	H-2-4
G-1-5	H-2-5
G-1-6	H-2-6
G-1-7	H-2-7
H-2-0	H-2-8
H-2-1	H-2-9
H-2-2	H-2-10
H-2-3	H-2-11
H-2-4	H-2-12
H-2-5	H-2-13
H-2-6	H-2-14
H-2-7	H-2-15

Goals

• Show single detectors show nominal performance.
• Show 12 & 16 detectors on a SQUID can be stable.

Planned measurements

• Network analysis (done)
• IV curves (done)
• noise (to be done for at least a x8 and x16 comb)
  • 1st stage SQUID controller board (data taken, to analyze)
  • SQUID noise (data taken, to analyze)
  • overbiased noise above Tc (data taken, to analyze)
  • overbiased noise below Tc (data taken, to analyze)
  • drop c0 90% in transition [compare nulled and un-nulled IV]
  • drop c0 80% in transition
  • drop c0 70% in transition
  • drop c3 90% in transition
  • drop c3 80% in transition
  • drop c3 70% in transition
  • drop c-1 90% in transition
  • drop c-1 80% in transition
  • drop c-1 70% in transition
  • drop all 90% in transition [verify stability of all detectors in transition]
  • drop all 80% in transition (data taken, to analyze)
  • drop all 70% in transition
• crosstalk
  • put helper 6-9 Hz away
• ETF

Results

• KT7_x16_netanal.pdf: Network analysis with the correct 22 uH inductors assumed
• KT7_x16_boloIV_20100520.pdf: First round of IV
• KT7_x16_boloIV_20100521.pdf: Second round of IV
• KT7_x16_boloIV_20100715.pdf: Last run of IV

Raw ADC power spectrum

• 16384 samples recorded at 25 MHz at the ADC.
• Closed RF room.
• SqCh2, 16x

• SqCh3, 8x

• SqCh6, 8x

• SqCh8, 12x

• Peak table

Frequency	SqCh2 ampplitude	SqCh3 ampplitude	SqCh6 ampplitude	SqCh8 ampplitude
MHz
0.48				0.015
0.95	0.025
0.96				0.030
1.44				0.032
1.91	0.048	0.016		0.173
2.38	0.039
2.39		0.014	0.017	0.182
2.86	0.201
2.87		0.050	0.066	0.805
3.34	0.313
3.35		0.098	0.108	1.44
3.81	0.124
3.83		0.056	0.057	0.981
4.29	0.116
4.31		0.027	0.015	1.08
4.77	0.019
4.79				0.236

• Main peaks separated by 480 kHz.

SQUID noise

• Regular noise data recorded at demod frquencies from 0.1-2 MHz with 2 kHz spacing.
• For each frequency, white noise level averaged between 1 and 5 Hz.
• Vertical lines show bias frequencies of bolos (Ch7 of SqCh6 not shown since bolo not biased, but peak fits where this bolos would be biased)
• SqCh2, x16

• SqCh3, x8

• SqCh6, x8

Raw ADC power spectrum take 2 (2010/07/23)

• Raw ADC measurement repeated.
• Measurement done with the QMC, the opto Ethernet converter and router on (the cryo board is powered on in the RF room, but not plugged in anything). Bath temperature ~1.6 K.
  • SqCh2, x16

• • SqCh3, x8

• Measurement done with the opto Ethernet converter and router on (the cryo board is powered on in the RF room, but not plugged in anything, the QMC is off [only difference with previous measurement]). Bath temperature ~1.6 K.
  • SqCh2, x16

• • SqCh3, x8

-- FrancoisAubin - 20 May 2010

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This topic: BolometerTesting > WebHome > PolarBear > 2009_PB_BoloKT7_x16 Topic revision: r8 - 2010-07-23 - FrancoisAubin

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