IFR Remediation 2002

SEXTANT 5 (Pre-remediation of August)

SEXTANT 5 (Official remediation)

List of remediated modules:

	Mod.1	Mod.2	Mod.3
Layer 19	POS	---	---
Layer 18	NEG	POS	POS
Layer 17	---	POS	NEG
Layer 16	---	---	---
Layer 15	NEG	POS	NEG
Layer 14	---	---	---
Layer 13	NEG	POS	NEG
Layer 12	---	---	---
Layer 11	---	POS	---
Layer 10	NEG	POS	---
Layer 9	NEG	POS	---
Layer 8	POS	POS	---
Layer 7	NEG	POS	NEG
Layer 6	---	---	---
Layer 5	POS	---	---
Layer 4	---	POS	NEG
Layer 3	---	---	---
Layer 2	---	POS	---
Layer 1	NEG	POS	NEG

Pre-remediation cosmic runs taken on Aug.21st:

Run 29740	6400 V
Run 29741	6600 V
Run 29742	6800 V
Run 29743	7000 V
Run 29744	7200 V
Run 29745	7400 V
Run 29746	7600 V
Run 29747	7800 V
Run 29748	8000 V
Run 29749	8200 V

Summary of remediation on sextant 5 here.

Plots of current and integrated charge here. Time in plots starts on Aug.22 at 13:00.

Stratigraphic view here.

Post-remediation cosmic runs for efficiency comparison, at 7.6 kV, are:

Run 29925	300kevts
Run 29940	1600kevts!?

SEXTANT 3

List of remediated modules:

	Mod.1	Mod.2	Mod.3
Layer 19	---	NEG	NEG
Layer 18	NEG	NEG	POS
Layer 17	---	---	---
Layer 16	---	---	---
Layer 15	POS	NEG	POS
Layer 14	---	---	---
Layer 13	---	---	---
Layer 12	POS	NEG	---
Layer 11	---	---	---
Layer 10	POS	NEG	POS
Layer 9	POS	NEG	POS
Layer 8	POS	NEG	---
Layer 7	POS	---	POS
Layer 6	POS	---	---
Layer 5	POS	NEG	---
Layer 4	POS	---	POS
Layer 3	---	---	---
Layer 2	POS	NEG	---
Layer 1	POS	NEG	---

Pre-remediation cosmic runs taken on Aug.23rd:

Run 29817	6400 V
Run 29818	6600 V
Run 29819	6800 V
Run 29820	7000 V
Run 29821	7200 V
Run 29822	7400 V
Run 29823	7600 V
Run 29824	7800 V
Run 29825	8000 V
Run 29826	8200 V

Summary of remediation on sextant 3 here.

Plots of current and integrated charge here. Time in plots starts on Aug.24 at 11:30.

Stratigraphic view here.

Post-remediation cosmic runs at 7600 V only:

Run 29944	500kevts
Run 29945	500kevts

SEXTANT 2

Pre-remediation cosmic run for efficiency comparison is #29986 at 7600V, with 500,000 evts.

Here is the list of remediating RPCs, the currents at nominal HV and mixture before start of remediation, and cartoons for the backward and forward sextant 2, showing past efficiency histories. HV channels PWR1-2-3 (red in the cartoons) were negative, PWR4-5-6 (blue in the cartoons) positive.

Final remediation currents and integrated charges in Sextant 2. Stratigraphic view here. Time in plots starts on Sep.24 at 12:00 (noon).

Summary of remediation on sextant 2 here.

Not all RPC's have integrated as much charge as needed, some for want of Ar flow and some for want of time. Based on the plots, I would recommend to consider for efficiency comparisons only these: 2-7-1, 2-16-1, 2-17-1, 2-18-1, 2-4-2, 2-5-2, 2-12-2, 2-14-2, 2-15-2, 2-16-2, 2-17-2, 2-18-2, 2-11-3, 2-16-3. This is not an official decision, just my feeling.

Post-remediation cosmic run for efficiency comparison is #30167 at 7600V, with ~106,000 evts.

SEXTANT 0

Pre-remediation cosmic runs for efficiency comparison are

Run#	HV
30070	7250
30071	7500
30072	7750
30073	8000

RPC's on negative remediation are: 0-4-1, 0-5-1, 0-6-1, 0-7-1, 0-8-1, 0-9-1, 0-10-1, 0-11-1, 0-12-1, 0-14-1, 0-15-1, 0-17-1, 0-18-1, 0-13-2, 0-14-2, 0-15-2, 0-16-2, 0-17-2, 0-18-2

RPC's on positive remediation are: 0-2-2, 0-4-2, 0-6-2, 0-8-2, 0-9-2, 0-10-2, 0-16-1, 0-2-3, 0-6-3, 0-8-3, 0-10-3, 0-13-3, 0-14-3, 0-15-3, 0-16-3, 0-17-3

Remediation for Sextant 0 ended today at 9:00 AM. Final plots for currents and integrated charges are below. (10/14 09:00AM) Remediation currents and integrated charges in Sextant 0. Stratigraphic view here.

Summary of remediation on sextant 0 here.

The Babar gas was restored to Sestant 0 at 2:00 PM and current monitoring has been going on since.

Post-remediation cosmic runs for efficiency comparison are

Run 30254	6800V	40kevents	trigg rate 50 Hz.
Run 30255	7000V	100kevents	trigg rate 100 Hz.
Run 30256	7200V	100kevents	trigg rate 150 Hz.
Run 30257	7400V	100kevents	trigg rate 200 Hz.
Run 30258	7600V	100kevents	trigg rate 200 Hz.
Run 30259	7800V	100kevents	trigg rate 200 Hz.
Run 30260	8000V	100kevents	trigg rate 220 Hz.

A second set of after remediation runs was taken on Oct. 18th to compare directly ( runs were taken at the same voltage) to the data collected on Oct. 4th.

Run#	HV
30346	7250
30349	7500
30350	7750
30351	8000

All these runs have 200 Kevents.

Pre-remediation cosmic runs taken on 10/13/2002 for efficiency comparison are

Run#	HV
30261	6800
30262	7000
30263	7200
30264	7400
30265	7600
30266	7800
30267	8000

Sextant 1 gas was changed to pure Argon today (10/14/2002) at 6:30 PM. Modules under remediation are :

Sextant 1

1-1(+) , 1-2(-) , 1-3(+)

2-2(-)

4-1(+)

5-2(-), 5-3(+)

7-1(+),7-2(-),7-3(+)

8-2(-), 8-3(+)

9-2(-)

10-1(+)

12-1(+), 12-2(-)

15-1(-)

16-2(-),16-3(-)

17-3(+)

18-1(-), 18-2(-), 18-3(-)

19-2(+),19-3(+)

Out of these 25 modules 1-17-3 was shorted out, so it was not possible to power it up; 1-19-3 is connected on H.V. distr. box F2 and, as of now, the relative GMB (together with other 3 GMB from CAN01) is not talking. We'll be working to fix this problem so that 24 modules total will be under controlled remediation. Remediation for Sextant 1 ended on 10/24 8:45 AM. After restoring the H.V. and monitoring connection the Sextant was switched to normal gas at 12:15 PM. H.V. was restored around 15:30; the sextant current was too high for the relevant pods before then. The current drop will allow us to measure the flow rate of the (normal) gas into the modules. It is worth noticing that Layers 7,8,13 and 19 that were fed gas both from the input and the output side were NOT restored to this condition, as it was not possible, as of now, to determine from where the gas, fed to the output leg, was coming from.

Remediation currents and integrated charges in Sextant 1 as of the last update below are shown. Stratigraphic view here.

An interesting set of plots can be found here : time history of the individual currents as normal gas is restored to the sextant gives us a better understanding of the gas flow in the sextant layers.

Post-remediation cosmic runs for efficiency comparison are

Run 30462	6800V
Run 30463	7000V
Run 30464	7200V
Run 30465	7400V
Run 30466	7600V
Run 30467	7800V
Run 30468	8000V

Pre-remediation cosmic runs taken on 10/19/2002 for efficiency comparison are

Run#	HV
30373	6800
30374	7000
30375	7200
30376	7400
30377	7600
30378	7800
30379	8000

To a first analysis of the reference data, the modules in sextant 4 can be classified as : 0.K. 29, completely dead 8, remediable 20. The situation from the latest data seems better that the one we had at the end of June. Modules that will undergo remediation are : 2-2,3-2,4-1,5-1,5-2,5-3,7-3,8-1,8-2,9-2,9-3,10-1,10-2,13-1,15-1,16-1,18-3,19-1,19-2,19-3.

The breakdown per layer is:

4-2-2 (-)
4-3-2 (-)
4-4-1(-)
4-5-1(-) 4-5-2(-) 4-5-3(+)
4-7-3(+)
4-8-1(-) 4-8-2(-)
4-9-2(-) 4-9-3(+)
4-10-1(-) 4-10-2(-)
4-13-1(-)
4-15-1(-)
4-16-1(-)
4-18-3(+)
4-19-1(+),4-19-2(+),4-19-3(+)

I concentrated the + in the forward and the - in the back. Of the 20 modules I plan to work on, 13 will go negative and 7 positive.

Remediation for Sextant 4 started on 10/24/2002. The new H.V. configuration was implemented at 11:00 AM and currents were recorded with normal gas at 5000V. At 15:00 the sextant was switched to Argon. As for sextant 1 four layers had a double gas feed: 10,13,15 and 19. During Argon flushing the double feed were disconnected.

Remediation currents and integrated charges in Sextant 4 as of the last update below are shown. Stratigraphic view here.

A very preliminary analysis of the module efficiencies can be found in here.

Last update on 11/03/2002 by M.Piccolo