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SEU Test Facility Frequently Asked Questions

What does the User Test Board Mounting Frame look like?

The following drawings of the User Test Board Mounting Frame are available:
Test Board Mounting Frame Without Spacers (Metric Dimensions)
Test Board Mounting Frame Without Spacers (English Dimensions)
Test Board Mounting Frame With Spacers Attached (Metric Dimensions)
Test Board Mounting Frame With Spacers Attached (English Dimensions)

What does the SEUTF Positioning Stage look like?

A digital photograph of the SEUTF Positioning Stage

What type of vacuum feedthrough connectors are used to interface between the Test Board and my Tester?

Connectors are mounted on connector feedthrough plates. See a Drawing of a Blank Plate.
The connector feedthrough plates can be custom made and exchanged.
Suitable O-rings are available at the SEU Test Facility.
User built connector feedthrough plates should be vacuum tested prior to your scheduled experiment.

The following feedthrough plates are available at the SEU Test Facility:

  • Two plates, each having six male/male, 40-pin, insulation displacement, ribbon cable connectors (IDC)
    Each feedthru consists of two IDC male headers soldered back-to-back.
    See a Drawing of 40-pin IDC Connector Vacuum Feedthrough.
    The pin pattern in the plane of the connector is inverted.
    Adapters are available to invert the pins again resulting in a one-to-one pin pattern.
    Maximim current rating is 1 amp per pin.
  • Four male/male, 50-pin, insulation displacement, ribbon cable connectors (IDC)
    Each feedthru consists of two IDC male headers soldered back-to-back.
    The pin pattern in the plane of the connector is inverted.
    Adapters are available to invert the pins again resulting in a one-to-one pin pattern.
    Maximim current rating is 1 amp per pin.
  • Five 37-pin D subminiature connectors
    2 Males outside to 2 Females inside
    3 Females outside to 3 Males inside
    Pinout is 1-to-1
    Current rating is 5 amps per pin
  • Fifteen female/female BNC coax connectors
    Plate material is aluminum.
    Shield connections of all 15 coax connectors are grounded to the vacuum chamber.
  • Fifteen female/female BNC coax connectors plus two 0.25 inch (6.4 mm) diameter plastic tubing fittings for cooling water
    Plate material is aluminum.
    Shield connections of all 15 coax connectors are grounded to the vacuum chamber.
  • Fifteen female/female BNC coax connectors
    Plate material is plastic.
    Shield connections of all 15 coax connectors are isolated from each other and from the vacuum chamber.
  • One 37-pin, one 25-pin male/female D-subminiature connector and six female/female BNC coax connectors
    Use of this feedthrough is discouraged.
    Plate material is aluminum.
    Shield connections of all 6 coax connectors are grounded to the vacuum chamber.
    The male D-subminiature connectors are outside and the female connectors are inside the vacuum chamber.
    The pin pattern is one-to-one.
    Gender changers of both sexes for the 37-pin and 25-pin connector are available.

Note 1: Female/female BNC connectors on plates 3, 4, and 5 can be changed to the female/female SHV connectors.
Note 2: Two connector feedthrough plates can be used at the same time.

What are the cable lengths required to connect my Test Board to the vacuum feedthrough connectors?

2-3 feet (61-91 cm) minimum cable length outside the vacuum chamber, depending on your tester.
3 feet (91 cm) minimum cable length inside the vacuum chamber.
2 feet (61 cm) minimum cable length inside the vacuum chamber when disabling the roll angle rotation.

What is the operating vacuum in the Test Chamber?

Typical operating vacuum in the Test Chamber is ~ 6.0 x 10-4 Torr

What is the time required to pump the Test Chamber down to operating vacuum?

Typically, it takes about 5 minutes to pump the Test Chamber from atmosphere to ~ 6.0 x 10-4 Torr

What size should my Test Board be?

Normal dimensions are 10 x 10 inches (25.4 x 25.4 cm).
18 x 18 inches (45.72 x 45.72 cm) is possible if the test board is symmetrically mounted on the frame.
Any dimension greater than 10 x 10 inches requires disabling the roll angle rotation.
Working area is 6 x 10 inches (15.24 x 25.4 cm).

How many devices can be mounted on the Test Board?

There is no practical limit to the number of devices that the software can handle.

What flux and fluence are available at the SEUTF?

Normal Flux range is 102 to 107 ions/cm²/sec.
Normal Fluence range is 103 ions/cm² to 1010 ions/cm² with test run times of 10 to 103 sec.
Higher fluxes and fluences can be achieved with some ions using a special dosimitry system.

What is the beam diameter?

Beam diameter is continuously variable from 0.2 to 3.0 cm.

Which ion beams are available and how long does it take to change from one to another?

There are over 50 ion species available covering an LET range from 0.015 to 91. Effective LETs obtained by varying the angle of incidence can be as high as 150 MeV cm2/mg. It takes about 15 minutes to change the energy of a given beam and between 30 and 40 minutes to change to a different ion. Most of this time is spent verifying the beam species and purity.

How much does it cost to perform a test at the Brookhaven Tandem and how do I set up an account?

There are different hourly rates depending on the type of contract under which your work will be performed. Please call our business office, (631) 344-7957, to find out the rate that applies to your situation. They will also be happy to set up an account for you and to explain the payment options. For a more detailed breakdown of costs take a look at Section B: Other Services, Tandem Van de Graaff, Cost per hour in the BNL Standard Rates table.

How do I find out when the facility will be available and how do I schedule a test?

You can look at the calendar and submit a Time Request on-line. We will then confirm your reservation by E-mail, phone or fax. You may also contact us if you have additional questions or need further assistance.

How do I get more information?

Contact us if you have additional questions or need further assistance.

How do I get a copy of the TVDG Facility User Questionaire?

Users are required to complete and return a TVDG Facility User Questionaire (.pdf) at least 7 days prior to the start of a run. If you do not already have one, selecting the previous link will get a copy of this form to your browser. You can print it, fill it out and fax it to (631) 344-4583. Alternatively you can call (631) 344-4581 and request a copy by fax or mail.

Can I monitor and/or control the temperature of the board and/or device under test?

We have vacuum feedtrough plates which can be used to hook up thermocouple wires. We also have one plate with feedthroughs for liquid cooling lines that some people have used. We also have small refrigeration circulators that you can borrow.

Is there a requirement for the test board to have a hole to allow dosimetry measurements?

No, the dosimetry is done with detectors with precise collimators placed upstream from the board. There are four stationary detectors which surround the useful portion of the beam, and a fifth one which is periodically introduced in the center position to verify uniformity.

Is there access to basic lab facilities such as a workbench, tools (like soldering iron, hand tools, wire, etc.)?

Yes, there is access to common hand tools, soldering equipment and some test equipment such as oscilloscopes, multimeters, and supplies.

Is it possible to obtain mating connectors and do cable fab at the fascility, if necessary?

Yes, we do have blank mating connectors which match the connectors on the feedthrough plates for emergencies.

What is the radiation exposure risk at the facility - around the vacuum chamber?

Radiation is continuously monitored with redundant detectors placed in close proximity to the chamber, and the upper limit there is set at 5 mR/hr. At the location users spend most of their time, the levels are much lower. In the rare instances when levels may approach 5 mR/hr, the tests are run from another room. Since the SEUTF can be run via remote computer, you can run all your tests from outside the target room, if you prefer.

Is there a special handling procedure required of our test board, after it has been irradiated?

Yes, our operators must inspect the irradiated parts with sensitive radiation monitors, before they can be transported. There is rarely any measurable activation.

Do I need to be trained in radiation safety to use the facility?

Required training to use the facility includes basic radiation safety.

Who was Van de Graaff?

Here is a short biography of Robert Van de Graaff.

Can I calculate my own LET values?

Yes. You may use the on-line LET calculator or download a personal copy of the LET Calculator program.

Can I get a copy of the SEUTF Manual?

Yes. You can download the Manual.