*GlowStick* GS4 run [UPDATE#5 - GS4 takedown]

Alan Goldwater says he is setting up to run the first GlowStick 4 experiments.

The cell will use a Coorstek mullite tube in differential configuration like GS3: two zone heater coil, one side filled with an alumina rod and the other with fuel.

The instrumentation and power control will be like GS3: sine wave AC with variac and PID controller, temperature sensed from K-Type thermocouple. As Alan does not have a suitable power analyser, this is the method available that will yield meaningful power measurements.

The Voltcraft IR meter will be used to check the thermocouple accuracy only and for other spot temperature measurements.

Thermal calibration with a null fuel load will establish a baseline data set.

The fuel will be Ni and LiAlH4, 10:1 by mass. Both powders were supplied by Alexander Parkhomov.

In addition to deciding quantity, there are some options to be considered for fuel preparation:

In preparation for this run, we asked Alexander Parkhomov for more detail on his material preparation and he duly obliged with the following information.

"The mixing and grinding of the fuel mixture I make in a porcelain mortar porcelain pestle with a duration of several minutes. You should check whether suitable LiAlH4 (whether is violent reaction with water). Preferably the Nickel before applying to dry, warming it at a temperature of 200 ° C for several hours."

The above information is important to all replicators and has been added to the "To Russia with Love" document.

The fuel will also be enclosed in a metal cartridge. Alan has 0.08 mm (.003") pure Ni foil available to make it. The material is rather stiff, but annealing may help before rolling it into a tube. Etching in HCl or FeCl3 after annealing may be needed to remove surface oxides, probably HCl would be better as both elements already exist in the Parkhomov LiAlH4.

Skip will be here to help with the long run time we hope to achieve.

The plan is to start around 24th August.

UPDATE#1 - Cell schematic and data feed

Here is the Schematic of Alan's latest variant of the *GlowStick*

Note that by adding a T piece to the pressure transducer, 2.5ml of dead volume has been introduced into the cell, meeting the requirements of Alexander Parkhomov suggested after the first heating of the Padua cell. By having the free volume and potential water formed condensing here may lower cell pressure. If the cell remains gas-tight, it may be interesting to see if noticeable water collects at the plug at the end of the experiment.

We are also very happy that the data for the GS4 will be live on HUGNetLab - this will allow followers the opportunity to track all the various parameters over time, with averaging - giving us all the insight that crowd analysis during a run can enable. You can see the data feed even before the experiment begins - here is a snapshot.

UPDATE#2 - GS4 first calibration is now running

A 5 hour ramp from ambient to 900 C (Outside Heater) was started an hour ago. The relevant data for this calibration is outside heater temp vs. core temp. and input power. and can be found on

http://data.hugnetlab.com/

Click the "view" button to the left of GS4

During calibration, the pressure sensor is not installed on the cell.

There is a dummy fuel load consisting of 1g. of Chinese Ni power (unknown quality) mixed with ~0.1 g. of Al2O3 powder. The cell is not sealed.

UPDATE#3 - GS4 Live run now

Stream here

https://www.youtube.com/watch?v=MqIJPG3bMF4

UPDATE#4 - Power analyser and re-heat

In Alan's own words

"The GS4 cell pressure has dropped to zero (gauge) after 10 days idle. If it continues dropping, permeation through or reaction with the mullite will be confirmed as the cause. Conversely, stopping at ambient pressure will indicate a leak big enough to admit air.

The PA1000 shoud be delivered today. After the pressure issue is resolved, I'll connect it to the intact cell and compare its readings to those of the DAQ system. I'll initially reheat the cell to 200 °C and hold for a day or so, then bump to 500 °C, or whatever profile is recommended from recent knowledge."

The pictures tell the story."