Scintillator Optical Test: DODECANE
Test Run
Baseline(nA) Ambient Temp(C)
Test Temp(C)
Test output(nA)
Post-Baseline(nA)
Post-Temp(C)
GDT2
74.6
21.6C
0.3C
35.8
72.6
21.4C
GDT3
164.6
22.1C
0.3C
83.3
161.1
22.2C
BDT1
35.5
21.4C
0.3C
26.0
----
21.3C
BDT2
149.1
22.2C
0.3C
68.0
144.6
21.8C
BDP1
168.6
20.8C
22.6C
153.8
167.1
21.5C
BDP2
156.1
21.3C
22.7C
151.7
156.0
21.2C
RESULTS:
1.
2.
Notes:
There is a light loss of ~ 50% as a measure of the photo-diode output current due to the temperature change from ambient
to 0.3C, for both the green and blue LED’s over the four test runs performed. As both LED’s produced similar results,
there does not appear to be frequency dependence in the visible spectrum we are interested in.
There was an inconsistent (and nominal) loss of between 3-9% for the pressure tests.
The blue laser (405 nm) was unavailable for the tests GDT1 – BDP2. I will be measuring the frequency distribution for
both the green and blue LED’S to provide our working frequency coverage.
The pressure test systematics were less reliable than the temperature test systematics as a result of not having a water
bath to maintain thermal equilibrium. The test temperature data was stable but above room ambient. Future pressure
tests will have the benefit of an ambient water bath. In light of the two pressure tests reported, and looking at the
pressure pretests I performed, there does not appear to be a light output dependence on pressure. This is what we
anticipated and is welcome news.
SYSTEMATICS:
Photodiode/ Output:
 Photo-diode light sensitivity is uniform over the diode surface with an abrupt drop at the edge of the diode, consistent over two
orthogonal axes using a surface pinhole test.

Anticipated photo-diode temperature dependence was reduced/eliminated by removing the component from the system during
cool-down. It was optimally positioned only when measurements were being performed and then set aside again.

Dark current/noise was: 0.2nA

Drift was: 3nA; consistent over all power settings and across both LED’s.

The zero point readout is: 0.04nA
Optical Path/ Components:
 Optical path components movement was minimized by using a water bath over ice pack; experience showed that jostling any
of the components (exception being the photo-diode) produced immediate and lasting effects on the data and noticeably in the
post–baseline tests, on the order of 10% - 30%.
Power Sources:
 LED: Input power was maintained by setting the power and either running the test with the system power/LED on or using the
power button to turn off system and bring it back online. Any output voltage variation was below the sensitivity of the multimeter (1mv). Incidentally; on tests GDT2 and BDT2 there was a measured voltage change of 0.2v, I suspect that it was
“touched” between the beginning of the test run and the post-baseline measurement was taken.
 Laser: Input power was set to 0.2mW and consecutive tests were run using the key and switch to maintain a consistent output
power. As noted in the manual for the Crystal laser, there is a two minute warm up time before the beam is stable.
Scintillator Optical Test: SS System w/ Nitrogen fill
Test Run
Baseline
Ambient Temp(C)
Test Temp(C)
Test output
Post-Baseline(nA)
Post-Temp(C)
LN2T1
4.48 μA
21.9C
0.5C
4.47 μA
4.47 μA
21.8C
RESULTS:
There is no signal/light loss due to the SS system being cooled from ambient to 0C.
Over the same path length, the SS system reduces the direct beam signal by 25%. The SS system optical path includes two 0.25 in.
sapphire windows and the SS tubing. The transmission curve provided by the manufacturer Swiss Jewel shows 85% transmission for
synthetic Sapphire. For two windows then I expected loss on the order of 30%, so my results are consistent with the data provided by
the manufacturer.
Scintillator Optical Test: PSEUDOCUMENE
Test Run
Baseline(nA) Ambient Temp(C)
Test Temp(C)
Test output(nA)
Post-Baseline(nA)
Post-Temp(C)
B1PP1
83.0
21.6C
21.6C
79.6
80.0
21.4C
B1PT1
73.7
21.1C
0.4C
0.3
49.0
22.2C
RESULTS:
The pressure test on Pseudocumene showed less than 4% light loss. Less than 4% because the post result shows a difference of 3.75%
with the baseline and only 0.5% difference between the test result and the post. The outcome is that there is no pressure dependence
for Pseudocumene. Three nanoamps difference is insufficient to suggest otherwise.
Optical schlieren prohibited producing data with confidence. At ~ 3.5C Pseudocumene goes basically opaque. Repeated tests to more
carefully control the temperature produced similar results. There is an observable change in Pseudocumene between 3.5 and 4.0C,
light may be observed looking down the beam pipe but there is extreme distortion. Carefully and slowly raising the temperature did
not change the results below 12C.
Scintillator Optical Test: KAMLAND MIX (80/20)
Test Run
Baseline(nA) Ambient Temp(C)
Test Temp(C)
Test output(nA)
Post-Baseline(nA)
Post-Temp(C)
B1KP1
174.0
22.3C
22.4C
245.0
211.5
21.4C
B1KT1
235.5
22.4C
4.3C
-----
-------
B1KT2
151.5
20.5C
4.0C
4.6C
15.8
27.5
-----
B1KP2
265.5
19.1C
19.2C
289.6
274.5
19.2C
RESULTS:
Now this gets interesting; neither Dodecane nor Pseudocumene showed any real change in light transmission due to pressure. When
mixed and under pressure (B1KP1) there was an increase in light transmission of 40%! While the post data remained some 20%
higher than the baseline. Doubting the data I collected, I repeated the pressure test (B1KP2) and measured a smaller increase of 9%,
while the post data remained 3% above the baseline. As there were no physical changes in the system or optics, there is no systematic
explanation for why the light transmission data was higher than the baseline figures which are optimized. If there were lensing or
warping, one would reasonably expect that the results would be lower and not higher.
The temperature test for the Kamland mix went similar to the Pseudocumene. Below ~3.7C the beam path looked opaque, then there
was light once the transition point was crossed. Repeated tests of raising and lowering the temperature around 4C confirmed that there
is a definitive change in the optical properties when the sample mix cools below ~3.7C rendering the mix opaque and “clear” above
3.7C. The light transmission for the Kamland mix is only 10%. This though comes as no surprise after reviewing the data
constituents.
Scintillator Optical Test: LAB (540L)
Test Run
Baseline
Ambient Temp(C)
Test Temp(C)
Test output(nA)
Post-Baseline
Post-Temp(C)
B1540LP1
369.0nA
24.6C
24.6C
356.0nA
358.0
24.5C
L540LP2
2.79 μA
20.7C
20.7C
2.61 μA
2.78 μA
20.7C
L540LT1
2.95 μA
20.4C
5.3C
0.54 μA
2.66 μA
20.6C
RESULTS:
The pressure tests for 540L produced a transmission loss of 3.5%, consistent with the pressure tests of all prior samples.
The temperature test for 540L produced a transmission of only 18% of the signal. The same type of transition was observed ~3.7C as
in the Kamland mix and Pseudocumene. Above 3.7C the sample looked “clear”, with obvious schlieren effects creating lensing.
Scintillator Optical Tests: LAB (N501)
Test Run
Baseline
Ambient Temp(C)
Test Temp(C)
Test output(nA)
Post-Baseline
Post-Temp(C)
LN501P1
3.48 μA
21.4C
21.4C
3.53 μA
3.52 μA
21.4C
LN501T1
3.52 μA
21.4C
4.0C
6.0C
2.67 μA
2.90 μA
3.55 μA
3.55 μA
17.8C
17.8C
RESULTS:
The pressure test for the N501 showed a slight increase in transmission of 1%, but no difference from the post test value. Again no
pressure dependence is observed.
The temperature test for N501 gave the first positive results of any of the sample candidates based on the limiting constraints for the
proposed Hanohano detector. At 0C the LAB sample remained “clear”, giving hope that we would get positive results for the first
time. At our test temperature of 4.0C, 76% of the baseline measurement was observed! This is at the low end of what I would foresee
with better systematics. There was a visible Schlieren Effect “U” below the piston tube that icing the tube minimized (reduced it to a
third of the original size), but further efforts failed to eliminate it. This aberration may be expected to contribute significantly to the
24% loss in transmission. Of note; raising the laser did not improve the test signal markedly. Switching the placement of the laser
and detector also had no effect.
Reviewing the second data point at 6.0C, the measurement improved another 6% within 2 degrees, although the “U” was still there
and the same size.
Scintillator Optical Tests: PXE
Test Run
Baseline
Ambient Temp(C)
Test Temp(C)
Test output
Post-Baseline
Post-Temp(C)
LPXEP1
1.74 μA
23.2C
23.2C
1.62 μA
1.69 μA
23.1C
LPXET1
1.69 μA
23.1C
2.0C
0.66 μA
1.67 μA
21.1C
RESULTS:
The pressure test for PXE produced a 7% difference from the baseline. This value is somewhat higher than those of the other samples.
Observation showed that PXE has a longer relaxation time to get rid of the Schlieren, and even providing extra time for the sample to
stabilize under pressure did not result in a measurable change in output signal. Based on experience PXE should fall in line with each
of the other pressure measurements, having no real pressure dependence.
The temperature test for PXE resulted in a transmission of 39%. The beam morphology appeared consistent just weaker in intensity as
observed on the detector end of the system. The PXE remained “clear”, yet there was obvious Schlieren even after 8 hours of
carefully controlled cooling.
Scintillator Optical Tests: DODECANE/PXE (70/30)
Test Run
Baseline
Ambient Temp(C)
Test Temp(C)
Test output
Post-Baseline
Post-Temp(C)
LPXEP1
1.31 μA
24.4C
24.3C
1.28 μA
1.30 μA
24.3C
LPXET1
1.30 μA
24.3C
4.0C
0.18 μA
1.27 μA
23.6C
RESULTS:
No pressure dependence for the Dodecane/PXE mix.
This mix is translucent at best at 4.0C, this will not work.