# Presentation: 502870

## Off-Axis Detector

- Quick Overview of Potential Detector Hall
- Gas Handling
- Some Soudan numbers
- ODH
- Flammable Gas

- Bill Miller, U of M

- Jan. 13,2003

## Possible Detector Hall

- Large 30 ft overburden makes it cost effective to put hall underground and use stable rock for sidewalls.
- Does raise some materials handling issues.
- More details on Detector Hall costs at meeting next week.

- Bill Miller, U of M

- Jan. 13,2003

## Detector Hall Dimensions

- Detector Area
- 100m long x 20m wide x 20m tall
- Detector hall
- This includes lifting bays, storage, office areas, egress walkways, access levels, stairs, elevators and mechanical area.
- 148m long x 28m wide x 29m tall
- Long 120m loading dock ramp to get loading bay under crane

- Bill Miller, U of M

- Jan. 13,2003

## Cross Section  Off-Axis Hall

- Bill Miller, U of M

- Jan. 13,2003

## Side view of Detector Hall

- Bill Miller, U of M

- Jan. 13,2003

## Floor Plan-Detector Area

- Bill Miller, U of M

- Jan. 13,2003

## Floor Plan-Loading Bay

- Bill Miller, U of M

- Jan. 13,2003

## Gas Handling

- Since the detector is note very far underground it is feasible to pipe from surface building.
- This makes gas delivery simple
- It is assumed that a gas mixing system would be used for the large volumes needed.

- Bill Miller, U of M

- Jan. 13,2003

## Soudan 2 Main Detector

- Argonne/15% CO2 gas mixed underground using dewers of Argonne and K bottles of CO2. We used on average about 200 cubic feet per day.
- The gas system tracked with the barometer keeping 2” water overpressure. We used a gas re-circulation system with DeOxo’s to remove oxygen.
- The detector had enough leaks the gas system did not exhaust except for very severe storms.
- We had 3600 m of gasket sealed cracks,  3600 m of 1” nylon return hose, 4500 m of 3/8” nylon supply hose, 1800 sweglock fitting, 4 gas pumps with DeOxo's and charcoal filters. Total gas volume about 9600 cubic ft.

- Bill Miller, U of M

- Jan. 13,2003

## Soudan 2 Veto Shield

- The Veto Shield consisted of roughly 1700 modules. Average size was 7 m long x 10 cm x 20 cm.  Total gas volume is about 8600 cubic ft.
- The Veto shield used a similar re-circulation system with a DeOxo to remove O2.
- The Shield had 13,600 epoxied wire connections, 6800 connections and thousands of feet of 3/8” nylon hose.
- Total leak rate was about 50 cubic ft/day

- Bill Miller, U of M

- Jan. 13,2003

## Total Soudan Gas Usage

- Approximately  18,220 cubic ft of gas volume (600 cubic meters)
- Total leak rate/top-up rate of about 250 ft/day (8.5 cubic meters)
- Volume of cavern 550,00 cubic ft (19,000 cubic meters)
- NO ODH problems

- Bill Miller, U of M

- Jan. 13,2003

## ODH in Off-Axis Hall

- Detector Volume comparison:
- Soudan=600 cubic meters
- Off-Axis=2400 cubic meters
- Detector Hall comparison
- Soudan=19,000 cubic meters
- Off-Axis=120,000 cubic meters
- Wild guess of leak rate :
- Soudan rate 8.5 cu. m/day
- Off-Axis (4x Soudan)=34 cu m/day
- Should still be OK for Oxygen levels

- Bill Miller, U of M

- Jan. 13,2003

## Flammable Gas Problems

- Gas detection devices needed
- Proper collection of leaked gas and venting out of cavern
- Emergency venting for power outages
- Mix gas in separate building on surface and pipe underground

- Bill Miller, U of M

- Jan. 13,2003