Difference between revisions of "Flow rate"

Revision as of 16:29, 2 November 2010

Fe55 with premixed 50/50 Ar/CO₂, New preamp and new HVB, ADC half-range, for a range of HV and (later) gas flow rate
From New HVB:

New preamp and HVB - max amplitude histo for 55Fe

New preamp and HVB - energy histo for 55Fe

Mixed 50/50 at 80 sccm total, less HV

max amplitude histo for 55Fe mixed 50/50 at 80 sccm

energy histo for 55Fe mixed 50/50 at 80 sccm

Mixed 50/50 at 40 sccm total - note the change in x-axis scale. The 2050V run was wrong initially, corrected 1340 Oct 27.

max amplitude histo for 55Fe mixed 50/50 at 40 sccm

energy histo for 55Fe mixed 50/50 at 40 sccm

Various gas flow rates at 1850V (left) and 2050V (right)

energy histo for 55Fe mixed 50/50 at 1850V

energy histo for 55Fe mixed 50/50 at 2050V

Events at 80 sccm total, 1850V (left) and 2050V (right)

energy histo for 55Fe mixed 50/50 at 1850V

energy histo for 55Fe mixed 50/50 at 2050V

Events at 40 sccm total, 1850V (left) and 2050V (right)

energy histo for 55Fe mixed 50/50 at 1850V

energy histo for 55Fe mixed 50/50 at 2050V

As above, zoomed in on pedestal... 80 sccm total, 1850V (left) and 2050V (right)

energy histo for 55Fe mixed 50/50 at 1850V

energy histo for 55Fe mixed 50/50 at 2050V

40 sccm total, 1850V (left) and 2050V (right) The little blip at ~ch 250 in the RH plot is an afterpulse, this is not noticeable at 2000V.

energy histo for 55Fe mixed 50/50 at 1850V

energy histo for 55Fe mixed 50/50 at 2050V

Premixed gas at different flow rates, cylinder -> small flowmeter -> CDC prototype.
I used the small flowmeter and the bubble count to very approximately match the flow rates to those from the mixer (only for reference to other results where the mixer was used; the premixed gas did not go through the mixer)...

80sccm from the mixer ~ off the top of the small flowmeter ~ 1.9 ± 0.2 bubbles/s
40sccm from the mixer ~ small flowmeter measures 57 ± 2 ~ 1.1 ± 0.2 bubbles/s
estimated c. 20sccm from the mixer ~ small flowmeter measures 27 ± 2 ~ 0.25 ± 0.02 bubbles/s - the prototype used to bubble at about this rate before we cooked it.
estimated c. 10sccm from the mixer ~ small flowmeter measures 15 ± 2 ~ 0.04 ± 0.02 bubbles/s

The non-linearity between flowmeter readings and bubble rate implies that the prototype is leaking at or below 40sccm. At higher flow rates, non-linearity between mixer readings and bubble rate might be caused by the small flowmeter obstructing the gas flow.

1850V, amplitude (left) and energy (right)

amplitude histo for 55Fe premixed 50/50 at 1850V

energy histo for 55Fe premixed 50/50 at 1850V

1950V, amplitude (left) and energy (right)

amplitude histo for 55Fe premixed 50/50 at 1950V

energy histo for 55Fe premixed 50/50 at 1950V

2050V, amplitude (left) and energy (right)

amplitude histo for 55Fe premixed 50/50 at 2050V

energy histo for 55Fe premixed 50/50 at 2050V