Low Temperature Xenon High Pressure Cell

Description of SSRL Xenon Pressure Cell for Cryo-cooling

The SSRL Xenon Pressure Cell for Cryo-cooling was developed and designed by SSRL scientists in collaboration with M.H.B. Stowell (CalTech). This device allows samples under moderate to high pressure xenon (or other gas) to be quickly flash-cooled ~10 sec after depressurization.

Instructions for Use of SSRL Xenon Pressure Cell

Prior to use:

Post the "Caution: Flash-Cooling Pressure Cell in Use" sign at the work area.

Operation:

• Read these directions before beginning and practice inserting and removing the cryo-pin from the cell.
• A small vial containing mother liquor, can be placed in the cell to prevent crystal dehydration. The height of the vial should not exceed ? to clear the crystal.
• Align a loop along the central axis a cryo-pin.
• Mount a crystal in the loop.
• The mounting pin is inserted into the pressure cell using the magnetic wand as demonstrated below. Remove the adapter ring for fitting Hampton style pins into the cell.

• Close the cell by screwing on the cap until hand tight.
• Close the vent valve (3).
• Close the gas input valve (4).
• Open the gas tank valve (1). The pressure in the tank will be shown on the tank pressure gauge (6). Then close the gas tank valve (1).
• The regulator valve is preset between 200 to 300 PSI and should not be adjusted.
• Carefully set the flow control valve (5) to zero.
• Open the gas input valve (4). This will slowly pressurize the cell as shown on the pressure cell gauge (8). If the pressure cell gauge does not show any pressure, contact the support staff.
• Open the gas tank valve (1) to fully pressurize the cell (200-300 PSI).
• Close the gas tank valve (1) and the gas input flow valve (4). The pressure in the cell should remain constant.
• Sample incubation times range from 2 to 20 minutes depending on mother liquor content, crystal size, etc... This requires some testing to find the best conditions for your sample.
• A fresh dewar of liquid nitrogen should be placed near the cell just before the cell is opened.
• Depressurize the cell by opening the vent valve (3) and then throttle the flow using the flow control valve (5). Although you can depressurize on the order of 5-10 seconds, this will tend to dry out your sample. However, longer depressurization times (up to ~30 seconds) may allow xenon gas to escape from the crystal.
• Watch the cell pressure gauge (8) and when the cell is depressurized, quickly remove the cap and transfer the cryo-pin directly into liquid nitrogen using the magnetic wand. The shortest time between depressurization and cryo-cooling that can be achieved using this device is ~15 sec.

Shut Down:

• remove mother liquor from cell.
• verify that the gas tank valve is closed.

Pressure Cell LT Parts And Prices

Vendor : Sunnyvale Valve & Fitting Company (408) 734-3145

ADJUSTABLE CHECK VALVE 1/4 FPT.	P/N SS-4CPA4-350	1 REQ.	$35.80 EA.
BALL VALVE 1/8 FPT.	P/N SS-42-F2	2 REQ.	$52.60 EA.
METERING VALVE 1/8 MPT - 1/8 SWAGE	P/N SS-SM2-S2-A	1 REQ.	$83.90 EA.
VERNIER HANDLE KIT FOR METERING VALVE	P/N NY-5K-S	1 REQ.	$16.10 EA.
1/8? MALE CONNECTOR MPT. - SWAGE	P/N SS-200-1-2	1 REQ.	$5.10 EA.
1/8? SWAGE NUT	P/N SS-202-1	1 REQ.	$1.53 EA.
1/8? FERRULE (FRONT)	P/N SS-203-1	1 REQ.	$0.87 EA.
1/8? FERRULE (REAR)	P/N SS-204-1	1 REQ.	$.081 EA.
TUBE ADAPTER 1/8 FPT - 1/8 TUBE	P/N SS-2-TA-7-2	1 REQ.	$5.60 EA.
CLOSE NIPPLE 1/8?	P/N SS-2-CN	1 REQ.	$3.00 EA
REDUCING ADAPTER 1/4 FPT. - 1/8 MPT.	P/N SS-4-RA-2	1 REQ.	$6.50 EA.
REDUCING BUSHING 1/8 FPT. - 1/4 MPT.	P/N SS-4-RB-2	1 REQ.	$4.10 EA.
STREET T 1/8?	P/N SS-2-ST	1 REQ.	$17.20 EA.
MALE TEE 1/8?	P/N SS-2-MT	1 REQ.	$11.60 EA.

Vendor : Beiderman (408) 956-5770

0-600 PSI. PRESSURE GAUGE SS. 1/4 MPT.	P/N 0555L-153254	1 REQ.	$24.49 EA.

Vendor : Teco (510) 426-8500

1/8 MPT. AIR DEFUSER	P/N M60-01	1 REQ.	$2.94 EA.
1/4 MPT. AIR DEFUSER	P/N M60-02	1 REQ.	$3.46 EA.

Vendor : Matheson (510) 793-2559

GAS BOTTLE RESTRAINT	P/N 510-R	1 REQ.	$76.00 EA.

Schematics of the SSRL Xenon Pressure Cell for Cryo-cooling