---++ Detectors

• cryostat run 20100811
• POLARBEAR wafer KT7 is used
• Reconfigured (channel to channel correspondence is not right for now) :
• From last run, SqCh2-Ch15 (w1-c14), SqCh6-Ch6 (w1-c5) and SqCh8-Ch1 (w3-c0) were plucked because of shorts to ground on the wafer.

Goals

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

Planned measurements

Measurement	Result	Status	Comment
Network analysis	see pdf below	done
IV curves	see pdf below	done	able to have all 15 detectors in transition
ETF measurement	see pdf below	done
Electronic noise	see 2010/09/03	need to double check prediction (Kate has nominal noise)	my transfer function might be off
SQUID noise 5K and 10K	see 2010/09/03	done	some frequencies show high noise, probably too close to f_bias, need to check
Overbias noise Tbath > Tc	see 2010/09/03	done
Overbias noise Tbath < Tc	see 2010/09/07	done
Overbias 90% in transition	see 2010/09/09	done	some good and bad bolos
Overbias 80% in transition	see 2010/09/09	done	some good and bad bolos
Overbias 70% in transition	see 2010/09/09	done	some good and bad bolos
Dropping "good bolos" 80% in transition	see 2010/09/13	done	good stays good
Dropping "bad bolos" 80% in transition	see 2010/09/20	done	bad stays bad
One channel at a time on SqCh2	see 2010/09/20	done	same as before
One channel at a time on SqCh3	see 2010/09/21	done	same as before
One channel at a time on SqCh8	see 2010/09/22	done	same as before
Crosstalk (helper 6Hz away from c1, 9H away from c2)	see 2010/09/16	data analyzed, waiting for conclusions
Repeat 80% and 90% with no cable through RF room	see 2010/10/04	done
flip x8 and x16		Need to warm up
Verify SqCh2 bad noise alternance		done	Ch2, 4, 6, 8, 10, 12, 14 & 16 all on same LC board (6 of 8 show high noise)
compare with old measurement		Bolometer to bolometer correspondence still to be figures out (lowest f not the same bolo in bith runs)	Ch1, 3, 5, 7, 9, 11, 13 & 15 was measured in the past KT7_SqCh1_x8_noise, need to reprocess prediction, measured values comparable (M17 : 17 pA/sqrt(Hz))
check tau_etf vs bad detectors	see 2010/10/04	done	no obvious trend
check responsitivity vs detector
compare loop gain vs tickle
compare old vs new network analysis

Results

• KT7_x16_x2_netanal.pdf : Network analysis with the correct 22 uH inductors assumed
• PB_KT7_x16_x2_boloIV.pdf: Nulled IV curves. Comb F, peak #8 does not show a turnaround, may be linked to the 1 ohm resistor in series with the capacitor (detector probably latches before the IV is taken).
• KT7_x16_x2_tauETF.pdf: Electro-thermal feedback measurements.

• Demodulated current increased by 5% for non-idealities
• Vb and resistance lowered by 15% to account for nuller leakage in bolos.
• 2010/09/03 :
  • Electronic noise is 20% too low.
  • SQUID noise : demodulated frequencies might not be all far enough from bias frequencies causing high noise (predicted noise not calculated properly).
  • SQUID noise : on resonance noise predicted as off transition on these plots -> noise is therefore expected to be too high on these plots.

state	b153-w1 (x15)	b153-w2 (x8)	b154-w1 (x6 weird)	b154-w3 (x11)	pdf
Electronic (SQUID ctrl 1st stage on)					PB_KT7_x16_20100903-M1.pdf
SQUID 10K					PB_KT7_x16_20100903-M2.pdf
SQUID 5K					PB_KT7_x16_20100903-M3.pdf
SQUID 5K on resonance (noise not predicted properly)					PB_KT7_x16_20100903-M4.pdf
oberbias (800mK)					PB_KT7_x16_20100903-M5.pdf

• 2010/09/07 :
  • For the 2nd measurement, the detectors are overbiased by ~30% more vs 1st measurement to make sure detectors are overbiased properly. Re-overbiased with the previous values right after the 2nd measurement.
  • The first 2 combs were dropped 80% in transition for the 3rd measurement. Then, the other 2 combs were dropped for the 4th measurement without nothing being done to the other 2 combs (no overbias for instance).

state	b153-w1 (x15)	b153-w2 (x8)	b154-w1 (x6 weird)	b154-w3 (x11)	pdf
overbias Tbath < Tc					PB_KT7_x16_20100907-M1.pdf
overbias more					PB_KT7_x16_20100907-M2.pdf
SqCh2 & 3 80% transition					PB_KT7_x16_20100907-M3.pdf
SqCh6 & 8 80% transition					PB_KT7_x16_20100907-M4.pdf

• 2010/09/09 :
  • Detectors are always dropped in transition from low to high bias frequencies. The last measurement here was done dropping the detectors from high to low bias frequency. Detectors were overbiased between the 4th and 5th measurement to see the effect of the dropping order.

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20100909-M1.pdf
90% transition				PB_KT7_x16_20100909-M2.pdf
overbias & 80% transition				PB_KT7_x16_20100909-M3.pdf
overbias & 70% transition				PB_KT7_x16_20100909-M4.pdf
overbias & 70% transition (dropped from high to low f_bias				PB_KT7_x16_20100909-M5.pdf

• 2010/09/13 :

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20100913-M1.pdf
80% transition (high predictions) or overbias (low predictions)				PB_KT7_x16_20100913-M2.pdf

• 2010/09/16 :
  • crosstalk measurements

SqCh3 (x8)

Measurement	State		Ch2 (c1)			Ch3 (c2)
		3 Hz	6 Hz	9 Hz	3 Hz	6 Hz	9 Hz
M5	overbiased - help Ch2+6Hz	0.129	534.202	0.087	0.032	0.148	0.038
M8	overbiased - help Ch3+9Hz	0.071	0.080	0.129	0.136	0.174	529.700
M11	overbiased - help Ch2+6Hz & help Ch3+9Hz	0.164	536.149	0.129	0.181	0.220	531.792
M18	80% trasition - help Ch2+6Hz	0.173	404.667	0.181	0.030	0.279	0.030
M21	80% trasition - help Ch3+9Hz	0.045	0.050	3.738	0.059	0.085	501.886
M24	80% trasition - help Ch2+6Hz & help Ch3+9Hz	0.513	407.138	3.814	0.503	0.841	504.100
M31	70% trasition - help Ch2+6Hz	0.069	680.848	0.094	0.058	8.134	0.074
M34	70% trasition - help Ch3+9Hz	0.051	0.050	14.532	0.144	0.096	793.427
M37	70% trasition - help Ch2+6Hz & help Ch3+9Hz	0.496	684.138	13.803	0.420	7.090	796.203

SqCh8 (x11)

Measurement	State		Ch2 (c1)			Ch3 (c2)
		3 Hz	6 Hz	9 Hz	3 Hz	6 Hz	9 Hz
M5	overbiased - help Ch2+6Hz	0.104	1532.782	0.083	0.065	0.727	0.076
M8	overbiased - help Ch3+9Hz	0.050	0.054	0.753	0.116	0.100	1493.984
M11	overbiased - help Ch2+6Hz & help Ch3+9Hz	0.409	1540.184	0.659	0.413	0.294	1501.989
M18	80% trasition - help Ch2+6Hz	0.071	1130.339	0.077	0.054	4.927	0.055
M21	80% trasition - help Ch3+9Hz	0.051	0.063	7.839	0.083	0.104	2026.829
M24	80% trasition - help Ch2+6Hz & help Ch3+9Hz	1.813	1137.267	7.230	1.853	3.025	2030.365
M31	70% trasition - help Ch2+6Hz	0.065	2003.567	0.059	0.052	13.201	0.059
M34	70% trasition - help Ch3+9Hz	0.043	0.050	3.802	0.070	0.076	2636.815
M37	70% trasition - help Ch2+6Hz & help Ch3+9Hz	1.656	2013.760	3.754	1.271	12.655	2642.449

• 2010/09/20 :

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20100920-M1.pdf
				PB_KT7_x16_20100920-M2.pdf
overbias Tbath < Tc				PB_KT7_x16_20100920-M3.pdf
Ch2 90% in transition				PB_KT7_x16_20100920-M4.pdf
Ch2 80% in transition				PB_KT7_x16_20100920-M5.pdf
Ch2 70% in transition				PB_KT7_x16_20100920-M6.pdf
Ch1 90% in transition				PB_KT7_x16_20100920-M7.pdf
Ch1 80% in transition				PB_KT7_x16_20100920-M8.pdf
Ch1 70% in transition				PB_KT7_x16_20100920-M9.pdf
Ch12 90% in transition				PB_KT7_x16_20100920-M10.pdf
Ch12 80% in transition				PB_KT7_x16_20100920-M11.pdf
Ch12 70% in transition				PB_KT7_x16_20100920-M12.pdf
overbias Tbath < Tc				PB_KT7_x16_20100920-M13.pdf
Ch11 90% in transition				PB_KT7_x16_20100920-M14.pdf
Ch11 80% in transition				PB_KT7_x16_20100920-M15.pdf
Ch11 70% in transition				PB_KT7_x16_20100920-M16.pdf

• 2010/09/21 :

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20100921-M1.pdf
70% in transition				PB_KT7_x16_20100921-M2.pdf
overbias Tbath < Tc				PB_KT7_x16_20100921-M3.pdf
Ch1 90% in transition				PB_KT7_x16_20100921-M4.pdf
Ch1 80% in transition				PB_KT7_x16_20100921-M5.pdf
Ch1 70% in transition				PB_KT7_x16_20100921-M6.pdf
Ch2 90% in transition				PB_KT7_x16_20100921-M7.pdf
Ch2 80% in transition				PB_KT7_x16_20100921-M8.pdf
Ch2 70% in transition				PB_KT7_x16_20100921-M9.pdf
Ch4 90% in transition				PB_KT7_x16_20100921-M10.pdf
Ch4 80% in transition				PB_KT7_x16_20100921-M11.pdf
Ch4 70% in transition				PB_KT7_x16_20100921-M12.pdf
Ch6 90% in transition				PB_KT7_x16_20100921-M13.pdf
Ch6 80% in transition				PB_KT7_x16_20100921-M14.pdf
Ch6 70% in transition				PB_KT7_x16_20100921-M15.pdf

• 2010/09/22 :

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20100922-M1.pdf
overbias Tbath < Tc				PB_KT7_x16_20100922-M2.pdf
Ch9 90% in transition				PB_KT7_x16_20100922-M3.pdf
Ch9 80% in transition				PB_KT7_x16_20100922-M4.pdf
Ch9 70% in transition				PB_KT7_x16_20100922-M5.pdf
Ch2 90% in transition				PB_KT7_x16_20100922-M6.pdf
Ch2 80% in transition				PB_KT7_x16_20100922-M7.pdf
Ch2 70% in transition				PB_KT7_x16_20100922-M8.pdf
Ch3 90% in transition				PB_KT7_x16_20100922-M9.pdf
Ch3 80% in transition				PB_KT7_x16_20100922-M10.pdf
Ch3 70% in transition				PB_KT7_x16_20100922-M11.pdf
Ch4 90% in transition				PB_KT7_x16_20100922-M12.pdf
Ch4 80% in transition				PB_KT7_x16_20100922-M13.pdf
Ch4 70% in transition				PB_KT7_x16_20100922-M14.pdf
Ch10 90% in transition				PB_KT7_x16_20100922-M15.pdf
Ch10 80% in transition				PB_KT7_x16_20100922-M16.pdf
Ch10 70% in transition				PB_KT7_x16_20100922-M17.pdf
Ch11 90% in transition				PB_KT7_x16_20100922-M18.pdf
Ch11 80% in transition				PB_KT7_x16_20100922-M19.pdf
Ch11 70% in transition				PB_KT7_x16_20100922-M20.pdf
Ch12 90% in transition				PB_KT7_x16_20100922-M21.pdf
Ch12 80% in transition				PB_KT7_x16_20100922-M22.pdf
Ch12 70% in transition				PB_KT7_x16_20100922-M23.pdf

• 2010/10/04 :
  • retake of previous measurements making sure no wire was going through the RF room wall to make sure RF has nothing to do with any bad results before.

state	b153-w1 (x15)	b153-w2 (x8)	b154-w3 (x11)	pdf
overbias Tbath < Tc				PB_KT7_x16_20101004-M1.pdf
80% in transition				PB_KT7_x16_20101004-M2.pdf
70% in transition				PB_KT7_x16_20101004-M3.pdf

• Responsitivity * Vb vs position in transition
  • Strong correlation. It indicates we need to correct Si and tau_etf to compare them with other values.
  • 

• tau_etf vs Responsitivity * Vb
  • Strong correlation, as expected from the Si*Vb vs postion in transition and the expected dependance of tau_etf on the position in the transition (loop gain)
  • 

• Responsitivity * Vb
  • This distribution is misleading since the bolometers are at different depths in transition
  • Expect 1 for Si if responsitivity is 1/Vb
  • get (1.3 +- 0.1 ) [same result if the 8 bolos of SqCh3 not there on x8 config are removed] (note, the sqrt(2) factor Hannes has in his thesis is corrected for here)
    • 

• tau_etf vs noise ratio of 70% in transition (2010/09/09) :
  • Since tau_etf depends on the position in transition, all those bolos are at different depths and we cannot correct for it, this plot brings no conclusions.
  • 

• Responsitivity * Vb vs noise
  • Since Si depends on the position in transition, all those bolos are at different depths and we cannot correct for it, this plot brings no conclusions.
  • 

* Responsitivity * Vb & tau_etf vs bias frequency

• • Since Si and tau_etf depends on the position in transition, all those bolos are at different depths and we cannot correct for it, this plot brings no conclusions.

-- FrancoisAubin - 07 Sep 2010

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This topic: BolometerTesting > WebHome > PolarBear > 2009_PB_BoloKT7_x16_2 Topic revision: r15 - 2011-01-19 - FrancoisAubin

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