Difference between revisions of "Oxford Helium Cryostat"

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== Manuals ==


On the Internal 11BM Staff staff SVN repository here:
== About ==
   
11-BM supports a Oxford closed flow Helium cryostat.  The sample is in direct contact with the cold He exchange gas. This can be used to cool small diameter capillary samples from ambient temperatures down to ~ 10 K with an in-situ spinner (or 5 K with no spinning)
https://subversion.xor.aps.anl.gov/11BMweb/Internal/trunk/staffdocuments/OxfordOptistatCF_HeliumCryostat_Documents/
 


== Helium Cryostat Image ==


[[Image:HeliumCryostatOverview.jpg|frameless|600px|Helium Cryostat Zoomed Image]]


== ordering Liquid Helium ==
== User Instructions ==


call Mary Berryman (FMS) on 2-3440 by 11 AM the day before to order Helium for next day delivery
=== Python Script to Log Cryostat Temperatures ===


normally order 100 L dewer
* Copy the file "[[CStemplog.py]]" to your User GUP directory
* Check if your directory contains an old log file named "CryoStat_Templog.txt" - if Yes, rename the old log file.
* Open a Terminal window (right click on mouse)
* At the command line - navigate to your current User GUP directory
(example: cd ~Users/GUP25248)
* At the command line, type "EPDpython CStemplog.py" to start the log scrip


leave a message if no answer; give name, full cost code, badge number, delivery location (433)




== factory default PID info ==
=== Changing Cryostat Samples ===


[[Image:OxfordITC_Cryostat_factorysetttings.png|frameless|600px|OxfordITC_Cryostat_factorysetttings]]
* Stop spinner motor (if using)


* Warm cryostat to > 280 K


== Wiring Notes ==
* Close B-Hutch Shutter


[[Image:PinDiagram_MaileView_10pin_Winchester.png|200px|frameless|PinDiagram_MaileView_10pin_Winchester.png]]
* Set cryostat control Mode to "H&G Manual" , set all 3 values to 0.


* Turn OFF power for spinner motor controller - inside left blue cabinet, motor # 5.  (if using)


* Turn OFF power to cryostat controller


* Disconnect cables on sample stick (Red = Sensor 2, Yellow = Auxiliary)


* Carefully pull sample mounting stick out of the cryostat.  Take extra care of the fragile wires and sensors.


* Cover the cryostat opening


=== Sample Stick A: Auxiliary ===
* Change samples on mounting stick - ensure new sample is the correct length.


'''Pins A,B,C,D = Phytron Stepper Motor'''
* Carefully re-insert sample mounting stick inside cryostat.
Motor Phase = Motor Wire  = 10 Pin  = Connector Wire  = Elco 
    1+          red          A          white          A
    2+          blue          B          black          C
    1-           yellow        C          red            E
    2-          green        D          brown          H
                             
              not used        E
              not used        F
                             
  '''Pins H, J, K, L = Diode Temp Sensor'''
  Diode  =  Diode Wire  = 10 Pin  = Connector Wire 
  V+        red              H          green     
  V-        white            J          white       
  I+        red/black        K          red       
  I-        white/black      L          black


=== Sample Stick B: Auxiliary  ===
* Check diode orientation with respect to the beam and sample


none
* Reconnect cables on sample stick (Red = Sensor 2, Yellow = Auxiliary)


* Turn ON power to cryostat controller


=== LakeShore Diode - ITC Sensor 3 ===
* Purge cryostat sample with Helium gas
1) turn on pump, open vacuum pump value
2) open gas cylinder, connect gas line
3) open cryostat value to sample space fully
4) close pump value, and slowly open gas value
5) bleed in Helium gas, but do NOT exceed 1 ATM pressure.
6) close gas valve, open vacuum pump
    repeat steps 4 -> 7 several times to purge sample space.
7) on last step, leave at under 1 ATM of Helium gas.
8) close gas, vacuum, and cryostat values
9) disconnect gas line, close gas cylinder
10) turn off pump


Diode = Diode Wire  = DB9 Pin =  ITC  = Connector Wire 
* Search Experimental Hutch
  V+      red          2    Input Low      green     
  V-      white        1    Input High      white       
  I+      red/black    4    Current +ve    red       
  I-      white/black  5    current -ve    black


* Turn ON power for spinner motor controller (if using)


=== Sensor 1 Notes ===
* Check sample alignment with the beam
Heaters (x2) + RhFe Resistor


'''Wiring ''' 
Pin      Function
A  -->    Heater + (x2, running in parallel)
B  -->    Heater -
C  -->    V+ Resistor
D  -->    V- Resistor
E  -->    I+ Resistor
F  -->    I- Resistor
H  -->    ?
J  -->    spare
K  -->    ?
L  -->    ?




'''Pin Resistance - NEW Cryostat ''' 
Pins        Expected (Ohm)  Measured (April 2011)
A-B  -->    15-25*            36
C-D  -->  30-40            34.5
C-E  -->  < 15              5.2
C-F  -->  30-40            34.6
E-F  -->  30-40            34.6
A-C  -->  > 1 M            open
A-GND -->  > 1 M            open
C-GRN -->  > 1 M            open
   
   
* according to Oxford, each heater is 68 Ohm.
Running parallel (1/R1+1/R2 = 1/Rtotal) gives Rtotal expected = 34 Ohms


== Manuals ==


'''Pin Resistance - OLD Cryostat ''' 
On the Internal 11BM Staff staff SVN repository here:
Pins        Expected (Ohm)  Measured (April 2011)
A-B  -->    15-25            36.5
C-D  -->  30-40            35.5
C-E  -->  < 15              6.0
C-F  -->  30-40            35.5
E-F  -->  30-40            35.5
A-C  -->  > 1 M            open
A-GND -->  > 1 M            open
C-GRN -->  > 1 M            open
   
   
https://subversion.xor.aps.anl.gov/11BMweb/Internal/trunk/staffdocuments/OxfordOptistatCF_HeliumCryostat_Documents/


== Transfer Line ==


On Cryostat - Inner Dimensions (receptacle on the cryostat)
== factory default PID info ==


<------- 38 cm ------->
[[Image:OxfordITC_Cryostat_factorysetttings.png|frameless|600px|OxfordITC_Cryostat_factorysetttings]]
<- 25 cm ->
            <- 13 cm -->
///
===========
            ===========
                      ===========
                      ===========
            ===========
===========
\\\


Transfer Line Stick Dimensions (when compression fitting correctly positioned)


<----- 36 cm ----->
== ordering Liquid Helium ==
        <8 cm > <8 cm >
///
=======
        =======   
              ||====
        =======    ^
=======  ^        |
\\\      |        |
He    return    feed


call Mary Berryman (FMS) on 2-3440 by 11 AM the day before to order Helium for next day delivery


== Python Control Software ==
normally order 100 L dewer


===SetupCryostat()===
leave a message if no answer; give name, full cost code, badge number, delivery location (433)
in robot.py
 
''Set up Oxford ITC503 Cryostat to default parameters''
 
def SetupCryostat(sensor=2, tries=5)
 
    sensor: sensor # to control against: 1=gas inlet; 2=cold block (default); 3=spare
 
    tries: number of repeats to try when sending the command before giving up (default is 5)
 
 
===GetCryostatT()===
in robot.py
 
''Read Oxford ITC503 cryostat temperatures''
 
def GetCryostatT(tries=5)
 
      input: number of times to attempt read (defaults to 5)
 
      returns a list of 3 temperatures: sensor1, sensor2, sensor3
 
 
===SetCryostatT()===
in robot.py


''Set Oxford ITC503 setpoint and optionally hold for temperature''
== 'GE' Varnish ==
'''MARCH 2013  - Dusted Grease Kapton is much better than Varnish.  Use of Varnish is NOT recommended ''' (See below)


def SetCryostatT(setpoint, WaitFlag=True, Delay=5, MaxWait=120, DeltaT=2, tries=5):
A <strike>preferred</strike> preparation method for 11-BM cryostat samples uses powder mixed with 'GE' Varnish to increase thermal transport between the sample capillary and helium exchange gas.


    setpoint (K) -- desired end T
GE Varnish is a varnish and adhesive which possesses electrical and bonding properties that make it an excellent material for cryogenic temperatures.  It can be ordered from Lakeshore under the name "VGE-7031"


    WaitFlag (default=True) -- if True the routine will return once the temperature is reached (default),
It is stable over the temperature range 0 - 423 K (150 °C)
                              False means return immediately after setting the ramp to begin


    Delay (min) -- period of time to wait after initially reaching the desired temperature in min (default is 5)
For more detail see:  http://www.lakeshore.com/products/cryogenic-accessories/varnish/Pages/Overview.aspx


    MaxWait (min) -- maximum period to wait for the selected sensor to reach the Set Point in min.
== More Details ==
                    If this period expires, an exception is thrown (defaults to 120)


    DeltaT (K) -- allowed discrepancy between the selected sensor and the desired T to start the delay period (defaults to 2)
*[[Wiring Notes]]
*[[Python Control Software]]


    tries -- number of repeats to try when sending the command before giving up (defaults to 5)




===SweepCryostatT()===
== CuFeO2 example==
in robot.py


''Sets Oxford ITC503 setpoint and optionally hold for temperature''
CuFeO2 is used at 11-BM as a low temperature "standard".  This CuFeO2 sample has been examined by several beamlines (powder and single crystal) to established a clear and abrupt transition at ~ 12 K.  Details are below.  If you prepare this powder in the same manor as your new cryostat sample you should be able to observe the transition.  If not, it may be a sign of poor heat transfer between your sealed capillary and the exchange gas - or a sign of significant beam heating.  Of course - each sample is unique, but we have found this to be a useful check.


def SweepCryostatT(startpoint, endpoint, sweeptime, WaitFlag=False, MaxWait=1.25, tries=5):
Phys. Rev. B 73, 220404(R) (2006) [4 pages]  http://prb.aps.org/abstract/PRB/v73/i22/e220404


    startpoint (K) -- desired start T for Temp
[[Image:CS_CuFeO2paper.png|frameless|600px| CuFeO2 paper]]


    endpoint (K) -- desired end T


    sweeptime (min) -- desired time for change from startpoint to endpoint (minutes)
'''11-BM data; reported temp is the exchange gas temperature as measured by sensor #1 at the end of the sample stick.
'''
[[Image:CS_CuFeO2data_Grease.png|frameless|600px| CuFeO2 Grease]]
[[Image:CS_CuFeO2data_Varnish.png|frameless|600px| CuFeO2 Varnish]]


    WaitFlag (default=False) -- if True the routine will return once the temperature is reached,
==March 2013==
                                False means return immediately after setting the ramp to begin (default)
Sample Mounting


    MaxWait (ratio) -- maximum period to wait for the sweep to complete as a ratio of the sweep time.
[[Image:CSsamplemount.png|frameless|600px|samplemount]]
                      Default is 1.25, meaning to wait 125% of sweeptime,
                      If this period expires, an exception is thrown.


    tries -- number of repeats to try when sending the command before giving up (defaults to 5)
[[Image:CS_2x_samplemount.png|frameless|600px|CS 2x samplemount]]
[[Image:CS_2x_samplemountb.png|frameless|600px|CS 2x samplemountb]]


[[Image:CS_2x_DustedSample_Mount_SpecFeScan.png|frameless|600px|CS_2x_DustedSample_Mount_SpecFeScan]]


===Example Code===
===Backgrounds===
s11bmwork% /APSshare/bin/python
Python 2.5.2 (r252:60911, Jan 28 2009, 15:33:22)
[GCC 4.1.2 20070626 (Red Hat 4.1.2-13)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path.append('/local/11BMcontrol/MailIn')
>>> import robot
>>> robot.GetCryostatT()
(1.3999999999999999, 407.80000000000001, 273.39999999999998)
>>>


>>> robot.gui.Sleep(1)
Background data for the 11-BM He cryostat are plotted below.  Intensity is plotted as '''SQRT''' scale
>>> robot.SweepCryostatT(1,2,1)
False
True
False
>>> robot.SweepCryostatT(1,2,1,WaitFlag=True)
True
False
  >>>


[[Image:CS_March2013_backgrounds.png|frameless|800px|CS_March2013_backgrounds]]


Data were collected in March 2013.


== Drawings ==
Scan parameters for all data-sets are:
# Calibrated wavelength = 0.413891
# Start 2theta (deg) =   -17.0
# End 2theta (deg) =     50.0
# 2theta step (deg) =     0.001
# Time per step (sec) =  0.01
# Calibration file =      11bmb_4771.calib


[http://s11bmsrv1.xor.aps.anl.gov/staffdocuments/Oxford_HeliumCryostat_CF1208_drawings.pdf Oxford_HeliumCryostat_CF1208_drawings.pdf]
File names/numbers are:
/mar13/11bmb_4817 = 1.5 mm Kapton/Varnish capillary, 5 K, with Al tail
/mar13/11bmb_4814 = 1.5 mm Kapton/Varnish capillary, 298 K, with Al tail
/mar13/11bmb_4774 = empty He CS, no sample capillary, 5 K, with Al tail
/mar13/11bmb_4815 = empty He CS, no sample capillary, 295 K, with Al tail
/mar13/11bmb_4816 = ambient air scatter only, nothing in beam

Latest revision as of 19:59, 28 July 2014

About

11-BM supports a Oxford closed flow Helium cryostat. The sample is in direct contact with the cold He exchange gas. This can be used to cool small diameter capillary samples from ambient temperatures down to ~ 10 K with an in-situ spinner (or 5 K with no spinning)


Helium Cryostat Image

Helium Cryostat Zoomed Image

User Instructions

Python Script to Log Cryostat Temperatures

  • Copy the file "CStemplog.py" to your User GUP directory
  • Check if your directory contains an old log file named "CryoStat_Templog.txt" - if Yes, rename the old log file.
  • Open a Terminal window (right click on mouse)
  • At the command line - navigate to your current User GUP directory

(example: cd ~Users/GUP25248)

  • At the command line, type "EPDpython CStemplog.py" to start the log scrip


Changing Cryostat Samples

  • Stop spinner motor (if using)
  • Warm cryostat to > 280 K
  • Close B-Hutch Shutter
  • Set cryostat control Mode to "H&G Manual" , set all 3 values to 0.
  • Turn OFF power for spinner motor controller - inside left blue cabinet, motor # 5. (if using)
  • Turn OFF power to cryostat controller
  • Disconnect cables on sample stick (Red = Sensor 2, Yellow = Auxiliary)
  • Carefully pull sample mounting stick out of the cryostat. Take extra care of the fragile wires and sensors.
  • Cover the cryostat opening
  • Change samples on mounting stick - ensure new sample is the correct length.
  • Carefully re-insert sample mounting stick inside cryostat.
  • Check diode orientation with respect to the beam and sample
  • Reconnect cables on sample stick (Red = Sensor 2, Yellow = Auxiliary)
  • Turn ON power to cryostat controller
  • Purge cryostat sample with Helium gas

1) turn on pump, open vacuum pump value 2) open gas cylinder, connect gas line 3) open cryostat value to sample space fully 4) close pump value, and slowly open gas value 5) bleed in Helium gas, but do NOT exceed 1 ATM pressure. 6) close gas valve, open vacuum pump repeat steps 4 -> 7 several times to purge sample space. 7) on last step, leave at under 1 ATM of Helium gas. 8) close gas, vacuum, and cryostat values 9) disconnect gas line, close gas cylinder 10) turn off pump

  • Search Experimental Hutch
  • Turn ON power for spinner motor controller (if using)
  • Check sample alignment with the beam



Manuals

On the Internal 11BM Staff staff SVN repository here:

https://subversion.xor.aps.anl.gov/11BMweb/Internal/trunk/staffdocuments/OxfordOptistatCF_HeliumCryostat_Documents/


factory default PID info

OxfordITC_Cryostat_factorysetttings


ordering Liquid Helium

call Mary Berryman (FMS) on 2-3440 by 11 AM the day before to order Helium for next day delivery

normally order 100 L dewer

leave a message if no answer; give name, full cost code, badge number, delivery location (433)

'GE' Varnish

MARCH 2013 - Dusted Grease Kapton is much better than Varnish. Use of Varnish is NOT recommended (See below)

A preferred preparation method for 11-BM cryostat samples uses powder mixed with 'GE' Varnish to increase thermal transport between the sample capillary and helium exchange gas.

GE Varnish is a varnish and adhesive which possesses electrical and bonding properties that make it an excellent material for cryogenic temperatures. It can be ordered from Lakeshore under the name "VGE-7031"

It is stable over the temperature range 0 - 423 K (150 °C)

For more detail see: http://www.lakeshore.com/products/cryogenic-accessories/varnish/Pages/Overview.aspx

More Details


CuFeO2 example

CuFeO2 is used at 11-BM as a low temperature "standard". This CuFeO2 sample has been examined by several beamlines (powder and single crystal) to established a clear and abrupt transition at ~ 12 K. Details are below. If you prepare this powder in the same manor as your new cryostat sample you should be able to observe the transition. If not, it may be a sign of poor heat transfer between your sealed capillary and the exchange gas - or a sign of significant beam heating. Of course - each sample is unique, but we have found this to be a useful check.

Phys. Rev. B 73, 220404(R) (2006) [4 pages] http://prb.aps.org/abstract/PRB/v73/i22/e220404

CuFeO2 paper


11-BM data; reported temp is the exchange gas temperature as measured by sensor #1 at the end of the sample stick. CuFeO2 Grease CuFeO2 Varnish

March 2013

Sample Mounting

samplemount

CS 2x samplemount CS 2x samplemountb

CS_2x_DustedSample_Mount_SpecFeScan

Backgrounds

Background data for the 11-BM He cryostat are plotted below. Intensity is plotted as SQRT scale

CS_March2013_backgrounds

Data were collected in March 2013.

Scan parameters for all data-sets are: 

# Calibrated wavelength = 0.413891 
# Start 2theta (deg) =    -17.0 
# End 2theta (deg) =      50.0 
# 2theta step (deg) =     0.001 
# Time per step (sec) =   0.01 
# Calibration file =      11bmb_4771.calib

File names/numbers are: 

/mar13/11bmb_4817 = 1.5 mm Kapton/Varnish capillary, 5 K, with Al tail 
/mar13/11bmb_4814 = 1.5 mm Kapton/Varnish capillary, 298 K, with Al tail 
/mar13/11bmb_4774 = empty He CS, no sample capillary, 5 K, with Al tail 
/mar13/11bmb_4815 = empty He CS, no sample capillary, 295 K, with Al tail 
/mar13/11bmb_4816 = ambient air scatter only, nothing in beam
Retrieved from "https://wiki-ext.aps.anl.gov/ug11bm/index.php?title=Oxford_Helium_Cryostat&oldid=1538"