GTK gas cooling system statusMarco Statera, Vittore Carassiti, Ferruccio Petrucci, Luca Landi

NA62 - GTK working group meeting 12-7-2011

OUTLINE

• installation• gas cooling system• working parameters

Na62 GTK working group meeting 12-7-2011 Marco Statera 2

installation

• three separate cooling stations• two trenches are fine, three are better• short lines: cheaper – lower losses• installation side: Jura - Saleve

3NA62 GTK working group meeting 12-7-2011 Marco Statera

SCHEME - liquid

Pro• liquid is a reserve of

gas• fast restart time after

an emergency stop• SHI CH-110 coldhead

170W@77K (+20%)

Cons• needs cryogenic

liquid• pumping vapour

(not only gas)

COST

• cryostat about 10k€

• engineering,blower and DC controller: 140k€

• cold head 16k€

• lines about 15 k€

• delivery 9 months 4Na62 GTK working group meeting 12-7-2011 Marco Statera

SCHEME – gas only

Pro• More flexible gas

temperature selection

• No liquid involved• Gas selection (He or N2)• Higher flow possible

Cons• refill by outer bottle• time between

emergengy stop and restart

• pressure 3-4 bara

COST

• vacuum, heat exchanger and pump 70 k€

• cold head 16 k€

• lines about 15 k€

• delivery 5 months

5Na62 GTK working group meeting 12-7-2011 Marco Statera

COST REDUCTION

• different suppliers• engineering and design (vacuum,

cryogenics, heat exchanger …)• Investigate a hybrid solution

6Na62 GTK working group meeting 12-7-2011 Marco Statera

TYPICAL MEASUREMENT

cooldown measure

warm upFLOW

Ta

TcTb

7Na62 GTK working group meeting 12-7-2011 Marco Statera

Nov 2010

COOLDOWNMay 2011Celsius – l/min

seconds

• manual regulation• the system is sensitive to flow regulation• a heater at the GTK inlet can regulate the lower temperature about 20 °C below the temperature during operation• even a 100 °C gradient introduces a maximum offset of

8Na62 GTK working group meeting 12-7-2011 Marco Statera

material α 10-6 1/K

Aluminum 22

Kapton 20

Silicon 5

Copper 17

G10 – FR4 11

€

(22− 5)10−6Δll ⋅K

100K ⋅30mm = 51μm

WARM UP

• self warm up – cooling turned off• max warming speed about 40 K/h• heating not required

9Na62 GTK working group meeting 12-7-2011 Marco Statera

Nov 2010

emergency

• about 25 seconds with the valve closed: temperature rise 4 K/s • @25 seconds power is stopped • no need of very fast interlock: about 1 second

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May 2011

CONCLUSIONS

• gas cooling systems can be installed in the cavern

• comparison of different cooling system• cost analisys of the gas cooling systems• standard cooldown and warmup data and

procedure shown• emergency state parameters were

investigated: response time ≈ 1 second

Na62 GTK working group meeting 12-7-2011 Marco Statera 11