Initials





























































Revision
00
Approved






Signature on File

3/16/05

Division
Head
Date





Preparer(s): K. C. Wu

SMD-OPM 8.1.3.23



Revision 00

Category B




March 9, 2005
The only official copy of this file is the one on-line on the Superconducting Magnet Division
website. Before using a printed copy, verify that this is the most current version by
checking the document issue date on the website.


SMD-OPM 8.1.3.23
1
Revision 00
Category B
March 9, 2005

8.1.3.23 Cryogenic Operation of AGS Cold Snake Magnet in B902

1.0 Purpose

This procedure provides instruction on the following operations of testing the AGS Cold Snake
Magnet in B902.



Pump & Purge the AGS Cold Snake Magnet.


Cooldown to 80 K using Liquid Nitrogen


Cooldown to 4.5 K using Liquid Helium


4.5 K operation

Warmup


2.0
Responsibilities and Scope

Operator is responsible for the cryogenic operations associated with testing the AGS Cold Snake
magnet.

2.1
After the cold snake magnet is installed in B902, the operator needs to connect
the supply line and the return lines.

2.2
The operator is responsible for the pump & purge operation to make sure the
system is clean and leak tight.

2.3
The operator is responsible for cooling the magnet to 80 K using liquid nitrogen.
It needs an estimated 1,200 Liter of liquid nitrogen and 24 hours, at a rate of ~ 50
L/hour.

2.4
After the magnet reaches 80 K, the operator needs to use helium gas to blow out
liquid nitrogen in the snake magnet and keeps those lines under vacuum.

2.5
The operator is responsible to cool the magnet from 80 K to 4.5 K using liquid
helium and the 4 cryocoolers. This process needs approximately 660 L of liquid
helium and expect to take about 12 hours. The four cryocoolers provide little
cooling at the beginning of 4.5 K cooldown, but should eventually provide
necessary cooling for steady state operation at 4.5 K

2.6
During initial test, several magnet quenches and rapid pressure rises are expected.
The operator is responsible to prevent overpressure by venting the helium gas to
recovery tanks. Although the system is protected with safety relief. It is import
to save helium after a quench.

The only official copy of this file is the one on-line on the Superconducting Magnet Division
website. Before using a printed copy, verify that this is the most current version by
checking the document issue date on the website.


SMD-OPM 8.1.3.23
2
Revision 00
Category B
March 9, 2005
2.7
After a quench, the Snake Magnet will reach about 12 K. The operator is
responsible for cooling the magnet to 4.5 K using liquid helium. During quench
and recovery, there is no interruption on operation of the cryocoolers.

2.8
At the conclusion of the test, the operator is responsible for warming up the
magnet to room temperature using the electric heater inside the Snake Magnet
with a small amount of helium flow to keep the magnet temperature uniform.

2.9
The operator is responsible for the control of environmental aspects as defined in
course number AM-ENV-F56.

3.0 Prerequisites

3.1
Operator shall be instructed by a supervisor or designee. Instructions shall
include:

3.1.1 The operation of vacuum pump, 1000 gallon liquid helium storage dewars
and the LN2 system.

3.1.2 The Process Control PC workstation for the Snake Magnet.

3.1.3 Operation of Sumitomo Heavy Industries, SHI, cryocoolers Model RDK-
408.


3.1.4 Venting helium after a magnet quench.

4.0 Precautions

4.1 Transfer liquid helium to Snake Magnet involves pressurizing the liquid storage
dewar in use. The operator shall not over pressure the liquid storage dewar.

4.2 Ensure personnel near unit are authorized, or accompanied by authorized personnel.

5.0 Procedure

5.1
Pump & Purge Cold Snake Magnet

5.1.1 Make sure the insulating vacuum of the snake magnet is established, below
10
-4
Torr.

5.1.2 Make sure the nitrogen and helium lines are properly connected to the Cold
Snake Magnet.
The only official copy of this file is the one on-line on the Superconducting Magnet Division
website. Before using a printed copy, verify that this is the most current version by
checking the document issue date on the website.


SMD-OPM 8.1.3.23
3
Revision 00
Category B
March 9, 2005
5.1.3 The operator needs to pump the helium side using the vacuum pump for the
Magnet Test Dewars, and the nitrogen side using a portable vacuum pump.

5.1.4 Switch pressure read out to Magnet Test Dewar 2 by turning Whitey valve
located behind the control panel near the distribution header. (Connected
to the vent line of the Snake Magnet)

5.1.5
Make sure all valves in the supply and the return headers of Magnet Test
Dewars are closed.

5.1.6
Open H5467A and H5466A on the Snake Magnet.

5.1.7 Open
AOV18

5.1.8
Crack open vacuum pump valve V4 to pump on the helium side of the
Snake Magnet.

5.1.9
After the pressure decreases somewhat, fully open V4.

5.1.10 The magnet pressure, as shown on PI0189, should reach 30in about 10
minutes.

5.1.11 When the pressure is less than 200 micron, on the vacuum gauge VI0175,
close V4.

5.1.12 Crack open HE16 to fill the helium side with clean helium.

5.1.13 After the 1
st
pump down, leak check shall be performed for all piping
connections.

5.1.13.1 Crack open MOV4 (warmup) to fill Snake Magnet to 7 psi on
PI0189.

5.1.13.2 Use Leak Teck to check all joints on lines specifically
connected to the Snake Magnet for this test.

5.1.14 Repeat steps 8 through 12 three times.

5.1.15 Pump & purge for the helium side of the Cold Snake Magnet is completed
and the magnet is connected to low pressure clean helium.


The only official copy of this file is the one on-line on the Superconducting Magnet Division
website. Before using a printed copy, verify that this is the most current version by
checking the document issue date on the website.


SMD-OPM 8.1.3.23
4
Revision 00
Category B
March 9, 2005
5.1.16 The pump and purge for the nitrogen side of the Snake Magnet is to be
performed using a portable vacuum pump.

5.1.17 To pump and purge the nitrogen side, close both valves at supply (N400a
and N400b) and vent (N402a and N402b) line for the nitrogen system.

5.1.18 Use the portable vacuum pump to pump on the line through V300M.

5.1.19 After the vacuum is established (below 200 micron), close V300M (inlet
to the portable vacuum pump).

5.1.20 Fill the line with helium through a bottle, and repeat pump one more time.

5.1.21 The Pump & Purge is considered complete.

5.1.22 The nitrogen system for the Snake Magnet is ready to accept nitrogen
flow.

5.2
Cooldown to 80 K for Cold Snake Magnet

5.2.1
Make sure the Cold Snake Magnet has been properly pumped and
purged for the helium side and lines for liquid nitrogen.

5.2.2
The 80 K cooldown is performed using LN2 directly from the B902
LN2 header with N2 gas vented outside B902.

5.2.3
Open N400a, N400b, N402a and N402b.

5.2.4
Manually open the LN2 supply valve HE6 on the LN
2
heat exchanger
above PAT refrigerator (this is the taping point) to flow through LN2
lines to the magnet and the shield.

5.2.5
On the PC work station, monitor cooldown rate from temperature
sensor TT1052N and TT1053N on the return side.

5.2.6
The temperature TT1052N and TT1053N will decrease with time. It
takes about 24 hours for the Snake Magnet to reach 80 K. The
cooldown rate is approximately 10 K per hour.

5.2.7
Close liquid nitrogen supply valve HE6.


The only official copy of this file is the one on-line on the Superconducting Magnet Division
website. Before using a printed copy, verify that this is the most current version by checking
the document issue date on the website.


SMD-OPM 8.1.3.23
5
Revision 00
Category B
March 9, 2005
5.3 Pump on the LN2 lines inside the Cold Snake Magnet (prior to 4.5 K cooldown)

5.3.1 Close valves N400a and N400b on LN2 supply, and N402a and N402b on N2
vent line.

5.3.2 Blow the nitrogen out of the 80 K cooldown lines using warm bottle helium.
Set regulator on the bottle for ~ 5psi. Open M412H and M414H.

5.3.3 After 2 3 minutes. Close M412H and M414H.

5.3.4 Disconnect the N2 vent line and connect return line to the suction of vacuum
pump.

5.3.5 Turn on portable vacuum pump and open V300M.

5.3.6 Observed vacuum on VT and PT

5.3.7 After the vacuum is established (below 200 micron), close V300M

5.3.8 The LN2 lines must be kept at good vacuum during the entire test to eliminate
potential undesirable heat load.

5.4 Coolodwn to 4.5 K and 4.5 K Operation for the Cold Snake Magnet


5.4.1 After the magnet reaches 80 K and vacuum is established in the 80 K
cooldown lines, one can proceed with 4.5 K cooldown. Liquid helium in
conjunction with the four cryocoolers will be used.

Note: During the 4.5 K cooldown, helium gas will return to the low pressure clean
helium system in B902 through AOV19, AOV23 and Moore Controller.

5.4.2 Turn on cooling water to