E907 Gas Systems


General Docs

Gas Specs for All Gases (html, Excel)
Detector Gas Matrix
General Questions and Comments on the gas systems
C4F10 Information for the RICH
Freon 13B1 S&H Discussion
Control System Options

Detector Specific Information

DC and TPC Supply Diagram
DC and TPC Distribution Diagram
TPC Notes

E871 HyperCP Gas System

Control System Options

Terry Tope:

In the test beamline next door, BTeV has a modern Siemens APACS+ slow control system. They bought part of it and part of it the lab already had in spares etc. This is the system that CDF uses to control all engineering processes. This would have to be worked out obviously, but I see no reason E907 could not use part the of system. The system can handle a much higher load than either experiment will create. The system could control the ckovs, gas mixing, and anything else that needs slow controls. Some modules would have to be purchased (around $3k total) , but the initial significant cost is taken care of. For about $3900 a PC development node could be set up in the counting house that would talk to the controls. It would have a graphical interface that can be configured as desired (see attached .jpg). CKOV set points could be entered and adjusted and the chamber gas mixtures could be graphically adjusted within pre set limits. Different users could have different premissions to control processes.

The system can archive temperatures, pressures, etc. as needed. For no additional hardware cost a web server could be set up so that that status of systems could be monitored offsite as CDMS is. I think this would be a great way to control the processes in the experiment.

Terry Tope (2/27/03):

Below is info on APACS slow controls for E907. One .pdf is sort of an explanation. The others are Fermi PO's that I label in stages to describe the order in which I think stuff should be purchased.

  1. stage1.pdf
  2. stage2.pdf
  3. stage3.pdf
  4. stage4.pdf

System Specific Diagrams

DC and TPC Supply Diagram
DC and TPC Distribution Diagram
TPC Notes


See the BCKOV gas page.

Drift Chamber and TPC Supply Diagram

Drift Chamber Gas System Diagram (proposed)

Drift Chamber and TPC Distribution Diagram

Drift Chamber Gas System Diagram (proposed)


TPC Notes

Dave Northacker:

I would like to use a pair of "high precision" mechanical rotameters to actually do the mixing (as was, and will be done for the EMCal), and for getting the gas to the chamber I would like to use the same type of system I plan on using for all the other chambers - a photohelic controlled input solenoid valve. This would allow for automatic gas shutoff to the TPC in the event the chamber pressure exceeded a certain value, with flow resuming once the pressure drops. The distribution gas rack I have been planning on using (a leftover E781 rack) has 8 separate photohelic controlled output channels, which will allow all 6 DC's and the TPC to run in this fashion.

BOC just gave me a quote for $9k for 54,000 ft3 of UHP P10. This comes out to about $0.20/ft3, which is pretty close to the $0.15/ft3 we pay to mix it ourselves using argon dewars and high pressure methane cylinders. A very preliminary quote of $0.37/ft3 was recieved from Airgas, and I am still waiting for the numbers from Praxair. If we really can knock the price of the trailer gas down to this level, it should be very seriously considered. Uncertainties with mix proportions over time will be completely eliminated over the lifetime of the experiment, since one trailer should last the whole run. In addition, deleting a high pressure methane station from the gas shed would be an added bonus.

E871 HyperCP Existing Equipment

E871 HyperCP Gas System Diagram (pdf)
E871 HyperCP Gas System Diagram

MC8 Gas Shed Contents

The key component for E907 is probably the rack set up to supply 9 chambers with either Nitrogen or chamber gas.


PDB, 4/11/03