high-temp life test #1 update jason mcphate lapp tuesday telecon 17 may 2011

High-Temp Life Test #1 Update

Jason McPhateLAPP Tuesday Telecon

17 May 2011

Dual MCP, High Temp Build

• All detector parts compatible with tube processing temperatures (350°C)

• Pair of Arradiance functionalized MCPs– INCOM “first batch” substrates, 33mm, 20µm, 60:1, 60%

OAR, 8°– Arradiance S/Ns S00613 (top), S00612 (bot). Resistance

matched (458 MΩ and 431 MΩ, respectively)– No inter-plate gap

217 May 2011 J. McPhate – LAPP Tuesday Telecon

Pre-Scrub 350°C Bake-Out

3

0 6 12 18 24 30 360

50

100

150

200

250

300

350

400

450Life Test Detector

Bakeout Small FlangeLarge Flange

Bake Time (hour)

Tem

pera

ture

(°C)


Principal outgassing component is hydrogen – dominant source would be stainless vessel• Bake performed on turbo pump

• Detector “pot” heated with two heater collars

• Temp at or over 350° for ~16 hours• RGA monitoring outgassing• RGA not pre-baked (error)

Photo-Current vs. Time

4

0 50 100 150 200 250 3000.00.20.40.60.81.01.21.41.61.82.02.22.42.62.83.03.2

Arradiance S613/S612 Scrub Current vs. Time

Scrub Time (Hour)

Scru

b Cu

rren

t (µA

)

Pretty flat


Begin at ~1 µAbump voltage to stay there

Bump Voltageto get ~2 µA

Now at ~3 µA

Ga

in v

s. V

olta

ge

RG

A O

utg

ass

ing

Ch

eck

Relative Gain vs. Extracted Charge

5

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.450%

20%

40%

60%

80%

100%

Arradiance S613/S612 Scrub Relative Gain vs. Extracted Charge

Extracted Charge (C/cm2)

Rela

tive

Gai

n 1 µA

2 µA3 µA


Despite bake-out, there is still significant initial gain drop from outgassing

Comparison to Commercial MCPs


• Both matched pairs of similar pore diameter

• Different L/D ratios• Both put through similar bake-out procedures

• Similar scrub extractions

• Scrub-down behavior is similar• Perhaps quicker stabilization for ALD MCPs

Extended Gain vs. Voltage

7

1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 30001E+1

1E+2

1E+3

1E+4

1E+5

1E+6

1E+7

Gain vs. Voltage @ 0.07 C/cm2(S000613/S000612)

MCP Voltage

Gain


• Measure gain in photon counting mode

• Switch to photo-current collection to extend to lower gain

• Increase flux to go even lower• Repeat

• Scrub gain about 200-300x lower than operational gain (when at 1µA scrub current)

RGA Scans at Start of 3µA Scrubbing


Scrub On-Off RGA Comparison


Principal MCP outgas component appears to be H2

high-temp life test #1 update jason mcphate lapp tuesday telecon 17 may 2011

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