Difference between revisions of "Fe55 peak shape"
(2 intermediate revisions by the same user not shown) | |||
Line 63: | Line 63: | ||
The light coloured plots were produced with the 55Fe source centred over the wire; for the darker plots the source was | The light coloured plots were produced with the 55Fe source centred over the wire; for the darker plots the source was | ||
close to the side of the tube. | close to the side of the tube. | ||
− | The operating voltage for that mix was previously chosen to be 1450V. Afterpulses are present at 1550V (delayed, so are not included in the integration). | + | The operating voltage for that mix was previously chosen to be 1450V. Afterpulses are present at 1550V (delayed, so are not included in the integration). The count rate decreased by approx 1/3 when moving the source to the side of the tube - with the 50/50 gas mix the count rate decreased by at least 1/2. |
{| border="0" cellpadding="2" | {| border="0" cellpadding="2" | ||
|width="400pt"| | |width="400pt"| | ||
[[Image:edge_9010_80_a.png|thumb|400px|max amplitude histo for 55Fe premixed 90/10 at ~80 sccm ]] | [[Image:edge_9010_80_a.png|thumb|400px|max amplitude histo for 55Fe premixed 90/10 at ~80 sccm ]] | ||
|width="400pt"| | |width="400pt"| | ||
− | [[Image:edge_9010_80_e.png|thumb|400px|energy histo for 55Fe | + | [[Image:edge_9010_80_e.png|thumb|400px|energy histo for 55Fe premixed 90/10 at ~80 sccm]] |
+ | |} | ||
+ | 90/10 premix at very approx 100 sccm<br> | ||
+ | {| border="0" cellpadding="2" | ||
+ | |width="400pt"| | ||
+ | [[Image:edge_9010_100_a.png|thumb|400px|max amplitude histo for 55Fe premixed 90/10 at ~100 sccm ]] | ||
+ | |width="400pt"| | ||
+ | [[Image:edge_9010_100_e.png|thumb|400px|energy histo for 55Fe premixed 90/10 at ~100 sccm]] | ||
+ | |} | ||
+ | 90/10 premix at 100 sccm<br> | ||
+ | {| border="0" cellpadding="2" | ||
+ | |width="400pt"| | ||
+ | [[Image:source_pos_9010_a.png|thumb|400px|max amplitude histo for 55Fe premixed 90/10 at ~100 sccm ]] | ||
+ | |width="400pt"| | ||
+ | [[Image:source_pos_9010_e.png|thumb|400px|energy histo for 55Fe premixed 90/10 at ~100 sccm ]] | ||
|} | |} |
Latest revision as of 16:05, 12 November 2010
Fe55 with 50/50 Ar/CO2, New preamp and new HVB, ADC half-range
Mixed 50/50 at 40 sccm total, moved the source (collimated as usual) across the top of the straw towards the edge.... With the source over the edge of the straw, the count rate halves and the camel disappears.
Overlaying side and edge data, the light coloured plots are with the source above the wire.
Repeated at 60 sccm
Events histograms with the source above the wire.
Events histograms with the source off the wire (above the edge of the tube).
90/10 Ar/CO2 (premixed) at approx 80 sccm
The light coloured plots were produced with the 55Fe source centred over the wire; for the darker plots the source was
close to the side of the tube.
The operating voltage for that mix was previously chosen to be 1450V. Afterpulses are present at 1550V (delayed, so are not included in the integration). The count rate decreased by approx 1/3 when moving the source to the side of the tube - with the 50/50 gas mix the count rate decreased by at least 1/2.
90/10 premix at very approx 100 sccm
90/10 premix at 100 sccm