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Notes of LAPPD Photocathode Development

SORMA 2012

Saturday 19 May 2012 - Filed under Uncategorized

SORMA 2012-ppt

SORMA 2012-pdf

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CHARACTERIZATION OF QUANTUM EFFICIENCY AND ROBUSTNESS OF CESIUM-BASED PHOTOCATHODES

Monday 7 May 2012 - Filed under Uncategorized

Dissertation

CHARACTERIZATION OF QUANTUM EFFICIENCY AND
ROBUSTNESS OF CESIUM-BASED PHOTOCATHODES

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Chalice cathode Recesiation Test

Friday 4 May 2012 - Filed under Uncategorized

Chalice cathode #6 is baked at 140 C for 2hrs for recesiation process test.

Cathode Recesiation Test

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Cathode QE Map Comparison

Friday 4 May 2012 - Filed under Uncategorized

The comparison of QE maps for two Hamamatsu 1 inch PMTs, one Burle PMT and one chalice 4×4 cathode.

QE Map comparison

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Recipe comparison

Tuesday 1 May 2012 - Filed under Uncategorized

the difference PC production process

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chalice 6

Tuesday 1 May 2012 - Filed under Uncategorized

chalice 6 updated

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Testing Bar Chart Readout of RGA

Monday 23 April 2012 - Filed under Uncategorized

On Friday April 20 codes to read out all atomic species 1-100 on the Spectra Vacscan RGA was tested. This mode is distinguished from the User Data mode which makes on 6 user selected atomic species available. A notable difference between the two modes is that the 6 species mode can be read out very rapidly ( typically with a min of 15 seconds per readout cycle) while the Bar Chart mode can take up to several minutes at the highest Gain setting.

The Vacscan in use on the Chalice can read atomic species A=1-100. A particular annoyance is that when the gain setting is high enough to read low occurrence species, then the high occurrence species are returned as <<< and values are returned to a precision of only 2 decimal places. Thus to get a reasonable result, 4 scans a 4 different gains must be acquired and combined for plotting. A typical result is show below.

Four Runs at different Gains then normalized to Gain of 1E-7

I note that runs at different gains do not produce identical results.! It is not clear to me that this represent the inherent precision of the device or some other systematic. The next plot show the result of summing up all the species.

Sum of all spcies at two different Gains again normalized to 1E-7

The non-reproducibility with gain setting is very clear.

Bar Chart Summed Data   User Chart Data

10^-8     10^-7                  Total Presure (10^-7)

2.5           3.3                        1.7

All normalized to 10^7

Ed May

 ::  Share or discuss  ::  2012-04-23  ::  edmay

Chalice RGA record for 18 April

Monday 23 April 2012 - Filed under Uncategorized

Chalice RGA user data chart recorder record Apr 18 930-1715.

Ed May

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Sb Transmittance measurement

Tuesday 17 April 2012 - Filed under Uncategorized

Sb transmittance data

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Pumping speed

Tuesday 10 April 2012 - Filed under Uncategorized

Pumping speed evaluation

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