Frequently Asked Questions

Thank you for your interest in our systems. The list of questions below is intended to serve as a guide for learning more about the system and confirming operational features for your experimental needs. Our goal is to ensure your goals and expectations are met throughout the process. If you cannot find the answer you are looking for in the links below or in other sections of our website, please call or email your sales representative to discuss directly.

We realize that for a system with many options and configurations, you may not know all of the questions to ask. Similarly, we may not have a complete and clear picture of your specific research goals, so we may not always know what to point out as particularly relevant to your unique requirements. 

To narrow the gap between these levels of understanding, and to help ensure all of your most important questions are answered throughout the process, we've also included additional "suggested" questions you may want to ask us. These are particularly relevant if your situation is unique or different from a standard purchase, or if any of your requirements in these areas differ from our standard procedures.

Getting Started

Having an instrument you can simply bolt to an optical table, insert a sample, push “cool down” and not even think about vibrations, temperature stability, or liquid cryogens was the goal when developing the Montana Instruments Cryostation. This makes it simple and efficient for the researcher or graduate student who is new to cryogenics, as well as the expert in cryogenics. There are a few basic techniques to learn, such as sample mounting and wiring best practices, but you're not on your own. The experts at Montana Instruments are here to help. 

View our Selecting a Research Platform guide for tips on a choosing a system to fit your experimental needs. If you are unsure, or just want assistance evaluating the various platforms and configuration options, contact us to talk directly with a design engineer or applications specialist.

Base Platform Components

The Cryostation Base Platforms include:

  • Cryostat (cold head and sample chamber) - the unique design allows the cryostat to be mounted on any optical table; most systems can be mounted at 45° or 90° on inch or metric tables (90° not available on all configurations)
  • Control Unit (electronics & vacuum pump) - can be placed on the floor, under the optical table, or on a nearby shelf
  • Variable Flow Helium Compressor - can be placed on the floor, under the optical table, or in a nearby space (may require long hose option)
  • User Interface PC (laptop with system monitoring and control software, connected via USB) - can alternatively be controlled via Ethernet remote interface

See Cryostation Base Platform Features for a more detailed overview of each component. 

No, we do not offer a water cooled compressor option. Having an air-cooled system gives the user more freedom to position the unit without restrictions of water proximity. Some users prefer to place the compressor in a utility closet or service hall; for this we offer 30 or 50 foot helium hoses and communication cables. This places the compressor out of the lab and prevents any warming of the laboratory environment. Some users who do not have access to an external room route the warm air coming from the back of the compressor directly into the HVAC system. Please contact Montana Instruments to explore these solutions.

No, it is integrated into the system. The system electronics include both system and user thermometry, which is fully functional and calibrated. Utilizing this thermometry, the system will automatically stabilize at the input temperature set point, based off of the PID of the platform thermometer. There are also several options to give the user additional control over the temperature of the system closer to the sample (learn more).

Yes, the included Control Unit has a diaphragm pump which automatically pulls a vacuum prior to the cool down. The pump and other controls may also be operated manually from the manual operations tab of the User Interface. In some cases, you may also want to use a Turbo pump to pull a vacuum before cooldown. See Montana Instruments Vacuum System for more details.

The cryo-cooler is an SHI RDK-101D, which is a Gifford-McMahon style. GM machines offer two main advantages: 1) They are more efficient than pulse tube cryo-coolers, and can be run on approximately 2kW of input power in standard operation (max 3.3kW); 2) The operating frequency can be varied for faster cool down. The cooler is suspended to keep vibrations off the table. The Montana Instruments systems utilize a proprietary design approach to ensure much lower vibrations than other technologies utilizing GM cryo-coolers.

System Operation & Remote Control

Yes! The User Interface PC (laptop) runs a Windows based utility to control the system. With internet access, the system can be controlled from another computer via network connection. This remote interface also allows a Montana Instruments service engineer to network into the system for real-time troubleshooting and diagnostic assistance. 

If the power goes out briefly, the inverters in the compressor will disrupt power to the cold head, causing the system to turn off for a few moments. It should start-up again on its own, but may lose communication. To regain communication, restart the software. If there is an extended power outage, power off the components and unplug them from the wall. This will avoid any sharp spikes in current when the system turns back on. The system will safely warm up on its own without heaters. Once the power is back on, plug everything in and restart the system as normal.

Yes, using LabView or any other code supporting TCP/IP communication, the user can build in temperature control of the system with their other experiments. Montana Instruments provides sample LabView VIs and DLLs for the user.

See How to Use LabView with Montana Instruments Software for more information. Many manual mode functions are not accessible via remote control, however, states can be read (for instance, if the pump is on or off).

Although we don’t provide specific support for Python and C++, both programming languages are capable of sending TCP/IP commands that are supported by the software.

Testing & Performance

We believe you need to see the key performance measures for your particular system, so we provide a Certificate of Performance on each system that is shipped. Every assembled system goes through a burn in of multiple cooldowns and warmups to ensure proper performance. We also run a comprehensive Built-In-Test program to test all of the core functions of the system and identify any potential problems prior to shipment. 

You can run the same Built-In-Test program as a diagnostic; we also have a diagnostics screen within the software to show you expectations that occur. Depending on your situation, our service and support team may recommend other tests.

Performance should be within specification and close to factory results. If you are experiencing large deviations in performance, please contact our service and support team for assistance. 

Our low vibrations platforms combine a series of clever and patented design approaches to minimize the trade-offs associated with typical closed-cycle systems. To address the challenges of moving components due to vacuum, the Cryostation uses symmetric bellows to create a net zero force on the sample chamber due to the vacuum inside the flexible bellows (see figure below). In the center is the tall cryo-cooler assembly, with a horizontal cold finger reaching into the sample chamber on the right. Two bellows are placed symmetrically at the base of the cooler support in the direction of the cold finger axis. If the system had a single bellows on the right, the drop in pressure to a vacuum would compress the bellows and exaggerate the motion of the cold finger laterally.  This not only would cause a displacement of thermal components, but would also require an equal and opposite force from springs or dampers, which only add to the force transmission across the bellows and increases vibration of the sample chamber. With two bellows in place, the pressure differential is balanced such that there is no lateral force on the sample chamber, no displacement of thermal components even when vacuum levels change, and minimal force transmission across thin bellows. The patent claims are detailed more in US patent 8746008 B1, “Low vibration cryo-cooled system for low temperature microscopy and spectroscopy applications.”

The integration of certain options, such as piezo nanopositioners or wiring, can affect base platform performance specifications. If you are concerned about base temperature and/or vibrations, please discuss your desired performance requirements with your sales representative or design engineer. They will be able to help approximate performance trade-offs for your unique system design. 

The power the system can dissipate depends on the temperature of the platform. The cooling power also varies across the different base platforms (see Cryostation Specifications for details). For assistance estimating the working temperature with your anticipated loads, contact our engineers and/or refer to the system Heat Load Maps.

Note: Our direct cooling design requires much less cooling power than some other cryocoolers, primarily due to how we handle thermal conductance through the system. We often notice other cryostats on the market that have much higher sample temperatures yet sill use much higher power. Our 100mW cooler can often cool samples better than a 2W cooler on another system.

The cool down time varies across the different base platforms (see Cryostation Specifications for details) and depends largely on the mass placed on the platform. If your system has added options, such as RF coax, wiring, or positioners, it will take longer to reach base temperature depending on the heat load added. Consult with your sales representative if you are concerned about cool down time. 

If the user connects a nitrogen tank or line to the Control Unit, the system will automatically purge and vent the cryostat with dry nitrogen upon warm up. A positive flow of nitrogen can also be maintained while changing the sample if the user wishes to keep the system free of moisture and contaminates. When the system is not in use, some users keep the system under vacuum. All base platforms pull a High Vacuum of about 1E-8 torr. 

Shipping

Delivery timelines can be influenced by a number of factors, including system complexity and options, production backlog, installation scheduling, and other design details. Upon receipt of an order and approval of any custom features, your sales representative should provide you with an estimated shipping date. If you need the system by a specific date, please discuss this with your sales representative prior to placing the order. 

Installation & Setup

See Preparing for a Cryostation Installation for a list of the main weights and dimensions of the system components.

This depends on a number of factorings, including the size of your room and the quality of your HVAC system setup. Our system generates about 3kW during cooldown, and about 2kW once cool.

See Unpacking & Setting Up the System for information on how to properly route cables and helium hoses during setup. The system manual will also include instructions on this. 

See Unpacking and Setting Up the System for detailed installation instructions (also includes a step by step video). Depending on the options involved, most users can unpack and setup a system in approximately 1/2 day. For systems with more than 3 options or custom design work, we strongly recommend the purchase of an installation. In the case of complex customizations, installation may be required to assure success. The installation will be bid as a separate line item on the quote.

Service

If you have questions during your installation, contact our service and support team for assistance.

Contact our service and support team anytime with questions about your system performance or setup.

Service and support is still available after your warranty expires. General troubleshooting and diagnostic assistance via email and phone is available for the lifetime of your system. After the warranty period, repair parts and labor are charged at standard rates.

Yes; contact your sales representative for information on our extended warranty packages.

Training

Yes, we have several videos and help articles online. We occasionally hold user training seminars at various locations (universities, trade shows, distribution centers, etc.) - if you are interested in hosting a seminar, please let us know. We can also arrange for on-site training for your group, especially in the case of systems with several custom options. This training is provided free of charge with the purchase of an installation. 

Yes, we encourage you to visit us! It is a great training opportunity for both your system and for general cryogenic knowledge. You are responsible for coordinating your travel, but there is no cost for a facility tour or on-site training. If you are planning a trip to the area, we also recommend you take advantage of some of the many recreational opportunities Bozeman, MT has to offer! 

Mechanical Setup

One of the main advantages of the system is its mobility and flexibility - the tabletop mounting architecture allows it to be placed only almost any optical table and into existing experimental setups. The user can use either a floated or non-floated optical table. Montana Instruments builds and tests the systems on 3’x5’x4” optical tables, although most users mount the system to a large, vibrationally isolated optical table.

For vibrational considerations, it is important that the system is secured to the optical table. The cryostat structure is bolted to the optical table at 45° or 90° (90° not available on all configurations) to the holes in the table (inch or metric). It is bolted in three places around the sample chamber, two places in the middle, and two at the back. The system can be easily moved or adjusted based on the setup requirements. 

The sample chamber is secured firmly to your optical table, so your sample is treated like an optical element. The cryocooler, however, is suspended within the housing frame. This unique design feature is the key to the success of the low vibration design.

The size of the sample space depends on the base platform configuration (see Cryostation Specifications for details). There are also several standard housing and castle options available to expand the working volume. 

To access the sample area and electrical connections, remove the lid and vacuum housing (simply lift off when not under vacuum) and remove the radiation shield (loosen four screws). The lower part of the housing contains the vibration isolation, temperature stabilization, and rigid sample mounting architecture which allows for near-zero drift over the entire temperature range. There is a lot of technology sitting below the sample area!

Sample Mounting

Standard systems include a versatile thermally damped sample mount, which provides an easily configurable way to position samples at various distances and angles with respect to the side and top optical ports. Please see Various Sample Mounting Configurations for Optical Access for details on standard mount configurations. Alternative sample mounts, such as stock designs for special configurations or custom designs for unique experimental requirements, are also available (see Sample Mounting Options for details). Please discuss your sample mounting requirements with your sales engineer.

Piezos

Open loop stages do not have feedback, so they are usually used for experiments where you want to "find" an area of interest, perform your measurements there, then move onto the next site. They allow very precise location. Closed loop stages allow the user to find features of interest, then go back to them later. They have less resolution in this mode - about 1-2um for positioning accuracy. Systems with closed loop stages can be easily switched to open loop operation, but open loop stages CANNOT be converted to closed loop. 

There are limits to this. Contact your sales representative if this feature is important. 

Interfacing Considerations

Wiring

All systems supply electrical feedthroughs for user connections into the sample space. These are most commonly used for piezo positioners, thermometers, and heaters. The number of feedthroughs is dependent on the base platform (see Cryostation Specifications for details). See Wiring Options for more information. 

See our How to Article on Wiring & Thermal Lagging or check out the more comprehensive Wiring Guide: A Complete Introduction.

We have a series of videos to show how to install your nanopositioners, see here.

Yes, to a degree. See our Performance Estimator for approximate temperature impacts of various wiring configurations. To minimize the impacts of wiring on temperature, be sure to follow Wiring Best Practices.

Yes, having a wire bond above your sample will raise the effective sample surface level. This is important for very low working distance setups. A typical bond height may be approximately 200um, plus the wire path above the surface.

Fiber Optics

This radius depends on your fiber. We can provide drawings of the sample chamber to you for this determination. 

We offer a series of standard fiber mounts (see Fiber Optics Options) or can design custom mounts for your requirements.

Fiber tapering is not a trivial task, and we do not have this expertise in-house. We recommend you consult with someone who has extensive experience doing so.

RF Coax

The quad RF side panel has the shields isolated, but internal wiring may ground the shield at the thermal lagging point. Contact your sales representative if this is important to your work, and we can discuss ways to workaround the isolation issues.

Optical Options

Windows

Both the vacuum windows and radiation shield windows can be replaced with any material or coating. See How to Remove and Replace Windows for details. If you have specific wavelength needs, we will work with you to get the proper material installed or provide the specifications for the system if the user chooses to install their own windows.

If you have specific requirements, please let your sales representative know during window selection. Our standard windows are fused silica, AR coated 400-1000nm, but many other options are available.

This is a common problem with Sapphire windows. We haven't heard of this issue on our other window options, but if this is a concern, please let your sales representative know during window selection.

Some windows have special effects. If this is important, please let your sales representative know during window selection.

We provide external window covers that you may use or remove.

Magnets

The available sample area depends on the pole spacing. See Configuration & Pole Tip Options for details. Also see Adjustable Radiation Shield for information on how to resize the sample chamber size.

Our sample mounts and thermal links have high copper content, and this may have eddy currents in the presence of changing fields. These currents may raise the temperature of the mount and your sample. The amount depends on the frequency and the field strength.

Yes. The user can go through true zero script to average it out. If you approach the field from the same direction this effect may be minimized.

There are two ways to ramp the magnetic field, either via analog input or via software script. You can attach a ramping voltage to the BNC analog input from an external power supply or signal generator. Alternatively, you can provide discrete steps to the field by sending text commands to the system via the Ethernet remote scripting language. Please consult your user manual for more information. 

Yes, we have various configuration options available to accomplish this. Please discuss your requirements with your sales representative.

Option Integrations

Options above the base of the chamber, such as low working distance windows, optical windows, housings and castles, and most sample mounts, are easy to add to a system. For the Cryostation s50 model, the Magneto-Optic module and Cryo-Optic module can be added at any time. For 100 (Fusion) & 200 (Nanoscale) classes, the Cryo-Optic must be added when the system is originally configured. Depending on your configuration (especially if your base platform included any custom modifications or several option integrations), some options may become more difficult to add without trade-offs (i.e. incurring a higher base temperature). 

It is difficult to install modifications to the base of the chamber, which include the recessed pocket for nanopositioners, the extended sample chamber option, and non-standard side panels. Each of these modifications will require a technician, and most cannot be modified in the field.

If you anticipate adding something later, please discuss this plan with your sales representative. Many options, aside from basic accessories, can become complex to install after delivery, especially if the system already includes a number of options. If this functionality or modification is important, we can arrange for you to send the cryostat back to our factory for the upgrades.

In theory, we can change any part of the systems we build, but some of these modifications may require a factory rebuild which can cause significant downtime and costs. We recommend the system is ordered in the configuration desired for current and future applications.

System Certifications

Yes, our products conform to the following CE directives: 2014/30/EU - Electromagnetic Compatibility Directive and 2014/35/EU - Low Voltage Directive. More information on these directives can be found by following the hyperlinks to the European Commission website. A copy of our Declaration of Conformity is also available upon request.