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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
10Na62 GTK working group meeting 12-7-2011 Marco Statera
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