Mon 14 Sep 09:50

Jordan moved the TC08 picolog 2 away from the chamber and built a makeshit heatshield. 
Picolog 2 was facing a slit in the cloth thorugh which the scroll pump flexible hose is connected.
Baking restarted in automatic mode from 80 C

12:09
Baking progressed OK - see attached.

~13:00
CJC 2 getting too high again. Baking went off. Jordan caught it and temporarily set in manual mode.
Moved picolog 2 further away. Increased amount of heatshield. Restarted in auto

17:30
Baking continues OK - see attached.
Will leave overnight.

19:30
Baking continues OK, T=124C , see attached.
However rates shown on Baking.x program appear nonsensical. Too high, too low, sometimes they all go to zero.
Clearly a bug in the code. Should not affect baking for now.
Will try to debug.

Sun 13 Sep 08:06

Baking reached 93 C yesterday afternoon at 16:18 and paused as a result of a percieved temperature gradient in
the octagon. 
See attached.

Left system overnight to check whether octagon gradient was going to equilibrate via convection. 
No changes this morning.
Thermocouple 1-8 labeled "Octagon (side)" likely is not in thermal contact with the octagon. 
It appears to have a temperature lower than room temperature. Possibly sits outside the tent? Gradient will not
decrease with time.

Temporarily overrode automatic mode, set temperature to 100 C, restarted automatic mode. Will keep monitoring.


Sun 13 Sep 10:00

Vessel reached 100 C, no gradients. All OK, except octagon gradient (ignoring).
Manually increased temperature to 110 C. Restored automatic mode.

Sun 13 Sep 12:00

Baking stopped automatically at 10:30 due to CJC temperature (aka room temperature 2) in TC-08 Picolog 2
exceeding 40 C.
Max operating temperature of picolog TC08 is 50 C, and accuracy is lost above 30 C.
https://www.picotech.com/data-logger/tc-08/usb-tc-08-specifications

Stopped baking. Removed thermocouple 1-8 "Octagon (side)" from Octagon gradient calculation and recompiled.
Restarted manually at T = 80 C

Please move picolog away from the tent tomorrow, and we can then increase temperature. Tent does not need to be
opened.

Sun 13 Sep 19:00
Vessel temperature at 80 C stable. 
Other temperatures stable. 
Leaving at 80 C overnight.

Saturday 12 Sep 08:43

Remotely checked status of baking. See attached.

Baking appears to be proceeding OK. No thermocouples disconnected.

Speed is slower than previously observed, limited by thermal gradients observed across both octagon and CARME
vessel as a result of new thermocouple placement.
Octagon gradient may not be real, and could be a result of placement of Octagon side thermocouple?

Main concern is temperature recorded by CJC in Picolog2 (aka Room temperature 2) at 31 C, increasing. 
The second picolog may be too close to the tent. If the temperature keeps increasing it may stop working. Will
keep monitoring.

All neg feed-throughs have now been fully installed, with ground tags 
and power wires crimped and attached to the correct pins. Feed-throughs 
are installed as seen in Image 
1 of zip file, with mark at the top of the feed-through. The pin 
assignment is seen in Image 2. The pins are assigned letters A to F, 
with F the top pin and C the bottom 
pin as installed(refer to images 1+2). The ground is pin c, with the 
two power wires connected to the bottom pins either side of the ground 
(pins b and d). Connections of 
wires from the negs to the feed-through is seen in image 3. Feed-
throughs have been electrically checked. The ground pin is checked 
against the chamber giving 
approx 0.5 ohms and the power pins are checked together giving 5-10 
ohms. Each of the power pins are open circuit with respect to the 
ground. A 
thermocouple has been attached under the bolt of one of the neg pumps 
(image 4).

Pirani gauge and hot cathode gauge have been installed on the chamber 
(images 5,6,7,8) on the section furthest from the turbos. 

Upper valve, turbo and supports have all now been installed (images 
9,10,11). Images 12,13 are of the internal of the turbo and turbo 
ports. The lower valve supports 
produced by the Daresbury group (image 14) are also now attached. These 
supports were required as the lower valve sits higher than anticipated 
due to shorter right-angled 
flanges.

Chamber is now ready to close and leak test!

4/6 of the neg feedthroughs installed. Continuity between the power pins, ground pin and the chamber has been checked, we observe 5-10 ohms between the power pins similar to previous checks on the heaters. Also attached are the crimps for the ground tag and feedthrough connector pins.  

Bakeout test completed. Maximum temperature reached within baking volume was 120 degrees, with baking stopped by the program due to detection of negative temperature gradients. Negative temperature gradients due to a couple of thermocouples becoming unsecured and moving to cooler part of baking volume. Attached documents show temperatures of thermocouples. The colour of plots are linked (all of chamber temperatures are blue etc). Temperature gradient across the chamber is low (less than 10 degrees). Heat loss at the front of the chamber is apparent in the air temperature gradient across the baking volume and between the RE72 temperatures. 

Thermocouples have been resecured (extra tape so hopefully won't fall again) and some repositioned. Heating jacket has been remounted at the front to prevent heat losses seen in first test. Quick heating test was performed this morning up to 50 degrees and it appears heat loss at the front of the baking volume is much reduced. 

Weeklong bakeout will begin monday morning. 

Initial bakeout started which will run until friday, temperature had reached 44 degrees when I left the lab. 

The bottom valve has now been installed on the main chamber

Internal neg installs completed and electrically checked. 

Using a digital multimeter confirmed continuity for SAES-supplied 
power cable (Amphenol (circular) 6-pin plug to Han 05 plug) for
the following pins

pin A - pin 5
pin F - pin 3

which correspond to the type K chromel/alumel thermocouple contacts
and Neg PSU output connector pins for the thermocouple (e.g. see p.34
of Neg PSU manual).

Week ending friday 14/08/20

CARME chamber securely mounted upon aluminium frame and support skis. Neg-ion pumps and right angled flanges installed. Neg pumps installed in the wall detector section of the chamber. Neg pumps continuity checked and are electically isolated from the chamber. 

Test