S.E. International URSA II User manual

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S.E. Internaonal, Inc. P.O. Box 39, 436 Farm Rd. Summertown, TN 38483 USA
1.800.293.5759 | 1.931.964.3561 | Fax: [phone]
www.seintl.com | radia[email protected]om
INTERNATIONAL
®®
OPERATION MANUAL
®

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Contents
Introducon......................................................................................................................................................4
URSA-II MCA Minimum System Requirements.............................................................................................4
URSA-II Technical Specicaon ..................................................................................................................................4
Hardware Descripon and Controls ..............................................................................................................4
Front End Panel ...........................................................................................................................................................4
Back End Panel............................................................................................................................................................5
Baery Compartment ...................................................................................................................................................5
Powering the URSA-II......................................................................................................................................5
AC Power Supply .........................................................................................................................................................5
Charging the Internal NiMH Baeries ..........................................................................................................................5
Using Alkaline Baeries ...............................................................................................................................................5
Alternate External Power..............................................................................................................................................5
Starng URSA-II for the First Time ................................................................................................................6
Inial Startup Steps ......................................................................................................................................................6
Funcons, Controls and Displays..................................................................................................................7
Main URSA-II MCA Window.........................................................................................................................................7
Menu Bar .............................................................................................................................................................7
File Menu ................................................................................................................................................................... 7
Ulity Menu................................................................................................................................................................ 8
Alarms........................................................................................................................................................................ 9
Misc ........................................................................................................................................................................... 9
View Menu................................................................................................................................................................. 9
Sound ...................................................................................................................................................................... 10
Library...................................................................................................................................................................... 10
Transfer ................................................................................................................................................................... 10
Help ......................................................................................................................................................................... 10
Buon Bar..........................................................................................................................................................11
Hardware Status Bar .........................................................................................................................................12
New User Hints Bar ...........................................................................................................................................12
Spectrum Display...............................................................................................................................................12
Spectrum Status Bar..........................................................................................................................................12
Acquision Controls and Indicators ...................................................................................................................13
Spectrum Smoothing .........................................................................................................................................14
Buon Panel ......................................................................................................................................................14
Full........................................................................................................................................................................... 14
Hardware ................................................................................................................................................................. 14
ROI Panel ................................................................................................................................................................ 15
Eciency ................................................................................................................................................................. 16
Peak-Based ............................................................................................................................................................. 17
ROI-Based ............................................................................................................................................................... 18
Sample Info.............................................................................................................................................................. 18
The “Print Preview” or “Report” Screen......................................................................................................................19
Using the Library Editor................................................................................................................................19
Using MCS Mode ...........................................................................................................................................21
Menu Bar....................................................................................................................................................................21
File Menu ...........................................................................................................................................................21
Ulity Menu ........................................................................................................................................................21
View Menu .........................................................................................................................................................22
Help....................................................................................................................................................................22
MCS Acquision Controls and Indicators...................................................................................................................22
MCS Analog Panel .....................................................................................................................................................23
Procedures.....................................................................................................................................................24
Calibrang a Detector with URSA-II...........................................................................................................................24
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Adjust Hardware Sengs...........................................................................................................................................24
Radiaon Source and Detector .........................................................................................................................24
Input and Polarity...............................................................................................................................................24
High Voltage ......................................................................................................................................................25

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Threshold...........................................................................................................................................................25
Coarse Gain and Fine Gain...............................................................................................................................25
Shaping Time.....................................................................................................................................................25
Determining Inial Hardware Sengs........................................................................................................................25
Performing an Energy Calibraon ..............................................................................................................................26
Performing a Shape Calibraon .................................................................................................................................28
Creang a Regions of Interest (ROI) Set ...................................................................................................................29
Manually Creang or Eding an ROI Set (“Manual Method”)............................................................................30
Performing an Eciency Calibraon ..........................................................................................................................31
Fine Tuning Hardware Sengs..................................................................................................................................32
Service............................................................................................................................................................33
Soware License Agreement .....................................................................................................................................33
Hardware Warranty ....................................................................................................................................................34

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Introducon
Thank you for purchasing a URSA-II (Universal Radiaon Spectrum Analyzer-II). A lot of me and eort was
spent trying to make the URSA-II hardware, soware, and this manual as user-friendly and error-free as
possible, but we cannot guarantee that no mistakes or omissions are present. All soware (and manuals, for
that maer) are “works-inprogress,” and will be updated from me to me. These updates will be posted on
our website, hp://www.seintl.com, where the most recent versions can be downloaded. There is also a link
to the URSA-II support website under the Help menu.
If you nd any errors or omissions or would like addional features in the instrument, please let us know.
URSA-II MCA Minimum System Requirements
The required soware to use the URSA-II has been tested on 32 and 64 bit Windows Operang Systems.This
soware has been tested on Windows 98, ME, NT, 2000, and XP.
URSA-II Technical Specicaon
• Internal 4096 channel successive approximaon analog to digital converter.
• Internal posive high voltage supply, variable from 0 to 2000V. Negave high voltage supply is also available.
• URSA-II accepts posive, negave, or pre-shaped (posive) pulses. Pulse heights should not exceed
approximately 5 volts.
• Uses 110V or 220VAC to 12V DC adapter (1.25A), or runs on 6 internally recharged NiMH “AA” baeries.
Rechargeable baery life is approximately 4 hours, but will vary considerably based on the power
requirements of the specic detector used. Baery charging circuitry can be suppressed via a switch in the
baery compartment to allow the use of standard alkaline baeries.
• ± 12V DC power for preampliers is available through the 7-pin mini DIN connector. This connector can also
provide +5V DC as well as logical outputs controlled by the soware’s alarm funcons.
Hardware Descripon and Controls
Front End Panel
1. On/O Switch.
2. Power on, LED glows red when URSA is on
3. Red LED indicates URSA is connected to 12 Volts
via power supply
4. Indicates charging state. Flashing Green indicates
baeries are charging, solid green indicates the
charge is complete..
5. SHV High Voltage connector . This provides the
high voltage output only for INPUT2 (i.e., will not accept a coupled signal).
6. BNC connector. This provides the signal input only for INPUT2 (i.e., does not carry high voltage).
7. DB9 connector. Communicaon port for connecng the URSA-II with a controlling device (e.g., computer).
2345 6
1
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8. DIN connector. This provides plus and minus 12-volt power if needed for detector preampliers. Also
provides plus 5 volts as well as logical outputs coupled to ALARM0 and ALARM1 in the URSA-II MCA soware.
9. S9- High Voltage C connector his provides high voltage and accepts coupled signal for INPUT1.
Back End Panel
1. External Power input. Accepts 12VDC at 1.25A. Input voltage should never exceed 15V, as damage to the
URSA-II could result.
Baery Compartment
2. Baery Type Selecon switch.
Recharge posion: Allows NiMH baeries to be charged.
Standard posion: The baery charging circuitry is disabled so non-rechargeable alkaline baeries can be kept
inthe URSA-II while connected to external power.
Powering the URSA-II
AC Power Supply
A 110VAC or 220VAC to 12VDC power supply is provided with the URSA-II. If you need to replace this for some
reason, make sure the output is a regulated 12VDC capable of delivering at least 1.25A connuous current.
The center pin is posive. Under no circumstances allow greater than 15VDC (or any AC voltage) into this
connector or damage to the URSA-II will likely result.
Charging the Internal NiMH Baeries
The URSA-II uses six “AA” 1800 mAh nickel metal hydride (NiMH) baeries. These are charged at either a slow
or fast rate, determined baeries voltages.
The NiMH baeries should power the URSA-II for about four hours. Note however that this gure can change
dramacally based on the current draw of the detector, high voltage, other hardware sengs, ambient
temperature, and age and condion of the baeries.
The expected useful lifeme of NiMH baeries under the best of circumstances is about one year.
Do not aempt to charge NiCad or Lithium Ion baeries in the URSA-II. Doing so will damage the instrument.
There is no problem with using the URSA-II while charging the baeries.
Using Alkaline Baeries
It is not a problem using non-rechargeable baeries in the URSA-II. Remove the four screws on the back panel
and replace the NiMH baeries, with AA alkaline baeries. However, you must be absolutely sure to switch
the Charge Switch to the Standard posion to bypass the URSA-II’s internal charging circuitry. Failure to do this
may result in catastrophic damage to the URSA-II. Switch it back to the Recharge posion when NiMH baeries
are reinstalled.
Alternate External Power
The URSA-II can also be powered from a number of other external sources away from AC power for extended
periods(i.e., longer than the internal NiMH baeries can support). All that is required is that a DC voltage
in the range of 12 to15 volts is provided to the unit. DC power from most motor vehicles can meet these
specicaons, and the URSA-II can be powered directly by a motor vehicle cigaree lighter adapter.

66
The center pin of the External Power Input is posive. Incorrectly applying voltage to the URSA-II will likely
damage it.
Starng URSA-II for the First Time
The URSA-II hardware and MCA soware are designed to connect URSA-II to a computer as painless as
possible. The URSA-II must be connected to a serial port via a serial cable.
The computer can be using Windows 2000, Win 10 or 11. Connect the serial port of the URSA-II to a USB
adapter.
It is not strictly necessary to have the URSA-II connected to start the soware. If an URSA-II is not found, you
will be given the opon of starng in oine mode. Should you start by doing this, there won’t be much to see
or do with the soware other than load previously acquired spectra (a couple have been included with the
installaon package).
Inial Startup Steps
1. Load the URSA-II MCA soware.
2. Aach the URSA-II to the computer via the serial connector. Also connect the detector.
3. Plug in and power on URSA-II.
4. Start the soware. URSA-II MCA searches all COM ports for the URSA-II automacally.
5. A detector must be entered before URSA-II can be opened.
Many of URSA-II’s calibraon les are ed to a specic URSA-II /detector combinaons.
6. Click the OK buon.
7. The Add New Detector window will open and
contain some default “generic” data the rst
me it is used. If you are in a hurry to try URSA-II
out, you can accept these values by clicking the
“Add” buon. It is recommended, that you take
a few moments and ll in the informaon for
the detector you will be using. All elds
must contain informaon. If you click the
“Cancel” buon, URSA-II MCA will revert
to the “Select Detector” window, which
will be blank. Your only opons then will
be to either close the applicaon or go
back to the Add New Detector window.
Click the Add buon aer you have
completed entering the informaon for
your detector.
8. The “Select Detector” window is now
displayed, showing thedetector just
entered. Click “Use This Detector.”
9. A window showing the serial number
of the URSA-II and the number of the
COM port being used is displayed. Click

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“Yes” to enable the high voltage to the displayed value or “No” to start URSAII MCA with the high voltage
turned o. It is recommended that you enable the high voltage at this me unless you have some reason to
believe that enabling the high voltage to the value displayed might damage the detector (e.g., the HV is higher
than you think it should be or you don’t actually have the detector connected yet).
10. The Main URSA-II MCA window
will now be displayed.
At this point, whether the rst use
or not, URSA-II MCA may appear
to pause for a few moments
while URSA-II MCA loads various
associated les including the library
le, the last used ROI set, energy
and eciency calibraons, and adjusts URSA-II’s on-board hardware sengs.
Funcons, Controls and Displays
Main URSA-II MCA Window
This window is the starng point for all
URSA-II funcons. This secon describes in
general terms the controls and displays on
the main window. Virtually all funcons can
be performed using either the mouse or
combinaons of keystrokes.
Menu Bar
Essenally all URSA-II MCA funcons can be
accessed through the menu bar, including those
triggered by buons on the Main URSA-II MCA window.
File Menu
The rst menu item (“Save Spectrum as File…”) is for saving a displayed spectrum to an URSA-II spectrum le
(*.usf).
The next two (“Save Spectrum and Load as Background…” and “Save Spectrum and Load to Stac Display”)
also save the spectrum but addionally either load the spectrum as the background spectrum or load it to the
secondary spectrum display.
The next two menu items (“Capture Screen to Clipboard” and Save Spectrum as Graphic…”) relate to the
graphical representaon of the spectrum, referred to in this document as the Chart. These allow the chart to
be copied to the Clipboard (and subsequently pasted into a word processing or graphics program) or saved
as a graphics le. These relate only to the Chart exactly as displayed, and do not carry over any other poron
of the window. Note: If you want to capture an image of the enre window, use Alt + Print Screen to copy a
picture of the acve window to the clipboard, and then paste into another applicaon.
The next group of three menu items (“Load Spectrum to Live…”, “Load Spectrum as Background…” and “Load
Spectrum to Stac Display…”) concern the loading of stored spectra. Any previously saved spectrum captured
using the same URSA-II and detector can be reloaded as a “live” spectrum for re-analysis or addional
acquision me, or as the background spectrum. Warning screens may be displayed if the spectrum was
acquired using dierent hardware sengs than are currently being used. Any spectrum in the *.usf format can
be displayed in the secondary spectrum.

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Note: If a saved spectrum is loaded to “live,” any spectrum currently displayed will be lost without warning unless
you explicitly save it before loading the saved spectrum. Note: When a background is loaded, it will automacally be
subtracted from the visual spectrum display unl cleared or de-selected from the View menu. A loaded background
spectrum will be subtracted from all subsequent analyses unl the background spectrum is explicitly cleared, another
one is loaded, or URSA-II MCA is closed.
The “Clear Background” menu item completely removes any loaded background le, not just from the visual display
(e.g., the background data also will not be used in subsequent analysis of spectra).
The next three menu items relate to the prinng of spectra currently displayed. “Printer Setup…” accesses the
Windows™ printer sengs dialog to alter paper type and layout, quality of the prinng, etc. “Print Spectrum Preview
(color)…” allows the user to view the printer output prior to prinng, adjust margins, etc. before prinng the chart.
“Print Spectrum Preview (B+W)…” does the same, but alters the displayed colors to a black spectrum on a white
background in order to save printer ink. This is the recommended method of prinng charts.
The nal menu item, “Exit,” closes URSA-II MCA. Warnings will occur if the currently displayed spectrum has not been
saved, and the user must conrm that the program should close.
Ulity Menu
The rst four menu items (“Start (or Restart) Acquision,” “Stop Acquision,” “Clear Spectrum,” and “Clear Spectrum
and Start New Acquision”) are for beginning, connuing, and stopping spectrum acquision as well as clearing
the currently displayed live spectrum. These items are idencal in funcon to the four buons along the top of the
Acquision Controls and Indicators poron of the screen. Note: No warnings are given if the current spectrum has not
been saved!
“Detector Status…” displays a small window displaying current informaon about the detector being used, loaded ROI
and library les, and the state of energy and eciency calibraons. The “Detector…” menu item opens a submenu
containing items that allow new detectors to be added, edited, or deleted,or for the detector being used by URSA-II to
be changed without closing URSA-II MCA. A menu item (“Disable High Voltage”) is also present for enabling/disabling
Buon Bar
Hardware Status Bar
New User Hints Bar
Spectrum Display
Spectrum Status Bar
Aquision
Controls and
Indicators
Spectrum
Smoothing
Buon
Panel
Menu Bar

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the high voltage to the detector (when HV is disabled, the menu item will read “Enable High Voltage).
“Detector…” opens a sub-menu containing various ulies for working with detectors.
“Add…” allows new detectors to be added in the same manner as during URSA-II MCA startup, without the
need to shut down and re-start URSA-II
MCA.
“Remove Detector…” allows deleon of
any detector entered except of the one
currently in use.
“Select/Change…” automacally disables
URSA-II’s HV supply to allow for safe
changing of detectors. A new detector is
selected from the list in a manner similar to
that performed on
URSA-II MCA startup. Once a new detector
has been selected, that detector’s sengs (hardware sengs, energy and eciency calibraons, and the last-
used ROI with that detector) are loaded and the HV enabled.
If “Disable High Voltage” is selected, URSA’s HV will be set to zero volts and the Hardware
Status Bar will display that the HV is o. This menu item will change to “Enable High
Voltage” and, if selected, will re-set the HV to the last-used hardware seng.
“Fine Tune…” opens a window to begin an automac ne gain adjustment roune.
“Energy Calibrate…” opens a window for performing an energy calibraon. See
instrucons on page 32.
The next seven [QQQ] menu items (“Full Screen” through “Sample Data Panel”) are
idencal in funcon to the seven buons in the Buon Panel on the lower right of the
Spectrum Display. Each of these opens a panel for a specic funcon along the boom
of the Spectrum Display, except for “Full Screen,” which closes any displayed panel and
restores the Spectrum Display to the largest possible. The funcons contained in these
panels are discussed in detail in the “Buon Panel” secon.
“Mul Channel Scaling Mode” disables and hides the Main URSA-II MCA window and
opens a new window for performing mul-channel scaling. This funcon is discussed in
detail in other secons of this Manual.
“Load ROI Set” is a redundant funcon (from the “ROI” panel) repeated here for
convenience.
“URSA-II COM Port…” displays which COM port URSA-II is currently connected through.
URSA-II can be used on COM 1 through COM 16.
Alarms
“Alarm Sengs…” opens a window where various alarms can be set. Alarms will only be acve if “Enable
Alarms” is checked. Alarms can be set for any ROI in the currently loaded ROI set or for the overall spectrum.
Alarms can be set for either a gross count rate or for an increase in gross count rate over a specied period
of me. Any two alarms can also be aached to the logical alarm outputs on the Mini DIN-7 connector. The
outputs go “high” (+5V) in an alarm condion.
Aquision
Controls and
Indicators
Spectrum
Smoothing

10
“Show Alarm Window…” opens the same window that is automacally opened when any alarm condion occurs.
Misc
This menu item is for special funcons
that do not easily t into other
categories. All of these item shave been
suggested or requested by users.
“Collect Mulple Sequenal Spectra”
opens a window where the URSA-II
can be told to collect a xed number of
spectra (or to sample connuously). At
the end of each acquision, the spectrum
le is saved with a sequenal le name.
Alternately (or, addionally), a brief ROI
report can be saved.
“Simple ROI Report” generates a minimal
ROI-based report containing primarily
count rate data for each ROI.
“View Spectrum as Spreadsheet” rst
prompts the user to save the spectrum
as a csv le (comma separated values),
then opens the spreadsheet using
your computers default applicaon for
opening csv les. In most cases, this
applicaon is a spreadsheet program such as Microso Excel.
“Save Spectrum on End of Acquision” will, when checked, save the spectrum to a le each me an acquision is
ended. This occurs when an acquision is ended by any method. The les are saved to the “Spectra” subdirectory
(o of whatever directory the URSA-II MCA soware is located) with the lename based on the date and me in the
format yyyy mm dd hh-nn-ss, where yyyy is the four digit year, mm is the two-digit month, dd is the two digit day of
the month, hh is the two-digit hour in 24-hour format, nn is the two-digit minutes past the hour, and ss is the two-
digit seconds past the minute.
“Disable ADC Correcons” will, when checked, disable the correcons made in the URSA-II’s microcontroller to
compensate for the analog-to-digital converter’s dierenal non-linearity.
View Menu
“Show New User Hints” enables/disables the New User Hints Bar, which displays a sentence or two briey describing
the funcon for any display or control the mouse cursor is currently over. Disabling (i.e., un-checking) this menu item
hides the New User Hints Bar, making the Spectrum Display slightly larger.
“Show Hints” enables/disables displays of small pop-up windows containing a very brief descripon of a control or
display when the cursor is over it for longer than one second.
When “Show Background Subtracted” is checked, the loaded background spectrum is visually removed from the live
spectrum. It does not aect display of a stac spectrum. Regardless of this visual seng, if a background has been
loaded it is subtracted in all analysis funcons. This menu item will be unavailable if no background spectrum has
loaded.
When “Show ROIs” is checked, regions of interest from the current ROI le are colored dierently than the rest of
the spectrum (unless color sengs are altered by the user). Addionally when this is checked, the ROI secon of the

11
Spectrum Status Bar will display the ROI name and number of total counts for the ROI currently under the
cursor.
If “Spectrum Quick Grow” is checked, the le axis of the spectrum display will be set to a minimal value when
the spectrum is cleared. This allows the fastest visual indicaon of peaks forming within the spectrum.
“Show Stac Spectrum” will show/hide the stac spectrum if one has been loaded. “Save Current Spectrum to
Stac Display” does just that, without removing or altering the current live spectrum. This funcon does not
save the stac spectrum in any way, and no analysis can be performed on a spectrum stacally displayed; it is
used for visual reference or comparison only.
In the next two menu items, the Primary and Stac spectra display mode can be changed between a line
display (default), a bar graph, or pixels.
“Grid Display Sengs” allows a grid to be overlaid (or not) on the spectrum display. Addionally, axis labels can
be displayed (or not).
“Show Isotope Data” and “Show Isotope Lines” are redundant funcons (from the Buon Bar) repeated here
for convenience.
“Linear Y Axis” and “Logarithmic Y Axis” change the display of the le axis.
The “Colors” menu item opens a sub-menu allowing most display colors to be altered. The “Reset to Default
Colors” menu item restores URSA-II MCA visual sengs to the “rst use” state. The default colors were
selected to reduce eye strain, especially on large monitors, but may not be ideal for all users or purposes (e.g.,
prinng). Use common sense in applying dierent colors. For example, if the Background color is set to be the
same as the Main Spectrum color, the display will appear blank.
“Undo Zoom” gives a method for restoring the zoomed state of the spectrum to “none” without requiring the
use of a mouse. The spectrum can only be zoomed by using the mouse to drag a rectangle (from upper le
down to lower right) on the Spectrum Display. Dragging any rectangle from lower right up to upper le will un-
zoom the spectrum.
Sound
Three opons exist for audible nocaon to the user that the acquision of a spectrum has been completed.
First is “No Sound,” i.e. the acquision just stops. In the second, “Ring Once on Acquision End,” a nocaon
sound (the
Windows “default” sound, usually a “ding”) is made once on compleon of an acquision. In the third
opon, the sound repeats approximately every second unl the userexplicitly acknowledges the fact that the
acquision has completed by clicking the “Acknowledged!” buon.
Library
“Load Library” allows the user to load one of the provided photon-eming isotope libraries or one created by
the user.
“Open Library Editor” opens an editor for modifying URSA-II library les. Using the library editor is discussed
elsewhere in the manual.
Transfer
These funcons allow easy copying of calibraon les from one computer to another or to a disk for transfer.
An example would be calibrang an URSA-II/detector combinaon on a desktop computer and transferring
that data to a laptop for eld use. Transfer of these calibraon les onto another computer should be
performed using the separate “URSA-II MCA Cal File Xfer” program provided, while URSA-II MCA is not

12
running. Funconally, this is idencal to copying all of the les contained in the “CalFiles” subdirectory onto a
oppy disk.
Help
The “Help…” menu item opens the URSA-II MCA Help le. (Note: The Help le has not yet been distributed as
of URSA-II MCA version 2.0.1)
The “URSA-II Support Website” is a hyperlink to (you guessed it!) the URSA-II support website.
The “About…” funcon opens a window containing informaon about URSA-II MCA and the URSA-II hardware.
“Version Informaon…” simply displays the version number of the URSA-II MCA soware.
Buon Bar
The le two buons (“Fine” and “MCS”) on this poron of the Main URSA-II MCA window provides quick
access to the Energy Calibraon window and the Mul Channel Scaling mode. These funcons are discussed in
detail elsewhere in this manual.
The dropdown menu contains a list of all isotopes in the currently loaded library that are enabled. Selecng
one of these isotopes allows data to be displayed as a table and/or as lines on the Spectrum Display.
Clicking the “Data” buon opens a window that shows the name and half life of the isotope, as well as the
specic data for all specic energies that are enabled in the library le. This window can be resized by moving
the mouse cursor on an edge unl the cursor becomes a double-headed arrow and dragging unl the desired
size is achieved.
The window can be moved to any convenient locaon by clicking the blue bar and dragging. When this window
is displayed, the buon capon becomes “Hide,” and clicking on it (or on the “x” in the upper right corner)
will close the window. The order of the display can be based on energy or yield, ascending or descending.
Change this by clicking on the top of the relevant column. Note:
The informaon in this display can be altered by using the Library
Editor, detailed elsewhere in this manual.
The “Show” buon will only be enabled if an energy calibraon has
been performed. Clicking the “Show” buon displays marker lines
at the energies where enabled library peaks for the current isotope
should reside. When the marker lines are displayed, the buon
capon becomes “Hide.” If “Yield” is also selected, the heights
of these lines are proporonal to the yield for each energy. If an
eciency calibraon has been performed, “E x” may be selected, which displays the line heights proporonal
to the yield for each energy mes the eciency at that energy mes the value in the box to the immediate
right. Selecng “Full” displays each energy line at the full height of the spectrum, regardless of yield.
Checking “Log” scales the heights of the energy lines against a logarithmic axis. Checking “Labels” displays a
small box over each energy line displaying the energy of that line in keV.
Hardware Status Bar
This secon along the top of the spectrum display shows informaon about the hardware currently being used
by URSA-II MCA. This includes the serial number of the URSA-II, the status of the high voltage supply (currently
on or o), and the serial number and descripon of the current detector.
The “Power” secon displays the voltage being supplied to the URSA-II power supply. This value is updated

13
on opening of URSA-II MCA, at the start of each acquision, and about every second or two during an
acquision. This value is not updated at any other me, i.e. when the URSA-II is sing idle. If the voltage
drops below 10 V a warning will be displayed, and at 9.5 V a message will be shown that the baery condion
is now crical and baeries should be replaced immediately.
New User Hints Bar
If “Show New User Hints” has been enabled in the View menu, a sentence or two appears here that briey
describes the funcon for any display or control the mouse cursor is currently over. Spectrum Display
Spectrum Display
This area graphically displays the spectrum data collected. This area can be zoomed by using and clicking the
mouse and “dragging a box” around the area of interest, from upper le down to lower right. This will not
work if the starng or ending points of the box are outside the Spectrum Display area. Once a spectrum is
zoomed, it can be panned by rightclicking the mouse on the spectrum display and dragging it. Un-zoom by
dragging a box (any size) anywhere on the spectrum display from lower right up towards the upper le.
Spectrum Status Bar
This secon along the boom of the main URSA-II MCA window displays informaon about the displayed
spectrum, whether currently acquiring or not, and whether or not the spectrum has been loaded to a le.
This display reects no informaon about any secondary spectrum that is displayed.
The rst group of three boxes (towards the le) reect data for the individual channel over which the mouse
cursor is located. These are the channel number, the energy associated with that channel (only if an energy
calibraon has been performed), and the number of counts in that parcular channel. If a background
spectrum has been loaded, the count displayed will reect the background-subtracted counts if “Show
Background Subtracted” has been selected under the “View” menu.
The second group of two boxes (in the center) shows data for whatever ROI the cursor is over, if an ROI set

14
is loaded and “Show ROIs” is checked under the “View” menu. If no ROI set is loaded, “Show ROIs” is not
checked, or the cursoris not over an ROI, these boxes will be blank. The rst of these two displays the name
given to the ROI, and the second shows the total (integrated) number of counts in that ROI. If a background
spectrum has been loaded, the count displayed will reect the background-subtracted counts if “Show
Background Subtracted” has been selected under the “View” menu.
The nal two boxes (towards the right) display overall data for the spectrum. The rst of these two displays
the total number of counts for the spectrum and the second displays an approximaon of the overall count
rate based on an average of the last 20 seconds of spectrum data. The overall count data will not reect
background subtracon. The overall count rate box may display misleading data for approximately the rst 20
seconds following the start of an acquision.
Acquision Controls and Indicators
The four buons along the top of this secon control the acquision of spectra. From le toright, these are
“Start,” “Stop,” “Clear,” and “Clear and Restart.”
The Start buon begins an acquision. If a spectrum is currently displayed but is not currentlyaccumulang
the acquision will re-start, adding data to the exisng spectrum. If a spectrum iscurrently accumulang, this
buon will have no eect.
The Stop buon ceases spectrum acquision. No data is destroyed, and the acquision can berestarted if
desired. This buon has no eect if the acquision has previously been stopped.
The Clear buon erases all data from the spectrum, and resets the elapsed me to zero. If
a spectrum is currently acquiring, acquision will stop. No warning is given before data is
deleted.
The Clear and Restart buon is equivalent to pressing the Clear buon followed by the Start
buon, and is provided for convenience. Again, no warning is given before data is deleted.
Immediately below these buons are two status displays. The top one of these will always be
visible, and gives some informaon about the status of URSA-II. The text of this display may be:
“Spectrum Clear” (red background). Indicates that the spectrum display contains no data, and URSA-II is not
acquiring data.
“Acquiring” (light green background). Indicates that a spectrum is currently accumulang.
“Acquision Stopped” (yellow background). Indicates that URSA-II is not currently acquiring data, but the
spectrum display contains data.
“Spectrum Loaded” (yellow background). Indicates that URSA-II is not currently acquiring data, but the
spectrum display contains data that has been loaded to Live from a le.
The second (and lower) of these displays gives informaon about the background spectrum, and will only be
visible if a background spectrum has been loaded. The text of this display may be:
“Bkgd Subtracted” (green background). Indicates that a background spectrum has been loaded and is currently
being subtracted from the visual spectrum display. It will also be subtracted from any spectral analysis
performed, including peak searches.
“Bkgd Loaded” (green background). Indicates that a background spectrum has been loaded but is not being
subtracted from the visual spectrum display. The background spectrum will sll be subtracted from any

15
spectral analysis performed.
Moving downward, the next object is the white “Time (sec)” input box, with a checkbox immediately to its
le. If thecheckbox is checked, URSA-II will stop acquiring a spectrum when the total counng me equals
this value. Time units are in seconds. An acquision cannot be started or connued if the checkbox is checked
and the acquision me equals or exceeds the amount of me in the input box. Typing in the Time box will
immediately un-check it; pressing Enter on the keyboard aer changing the Time value will re-check it.
Directly underneath the “Time (sec)” input box is the white “Total Counts” input box, with a checkbox
immediately to its le. If the checkbox is checked, URSA-II will stop acquiring a spectrum when the total
number of accumulated counts equals this value. An acquision cannot be started or connued if the checkbox
is checked and the total accumulated overall counts equals or exceeds the number of counts in the input box.
Typing in the Total Counts box will immediately un-check it; pressing Enter on the keyboard aer changing the
Total Counts value will re-check it.
The nal item in this area is the gray “Time (sec)” box. This displays the total counng me, in seconds, for
the spectrum currently displayed. If a spectrum has been loaded to Live from a le, this display will reect the
amount of me for which that spectrum was counted.
Spectrum Smoothing
The photomulplier tubes used NaI(Tl) gamma detectors (as well as many others) do not supply a smooth
connuum of energies. This fact is not apparent when the spectrum is displayed in 256 or so channels. URSA-II
MCA’s 4096 channels of data can be ltered to give a smoother representaon of the energy connuum. Try
using dierent values of smoothing to get the “best looking” spectrum display. Smoothing is applied only to
the visual display and has no eect whatsoever in performing peak searches and analysis.
Buon Panel
The buon panel provides access to the primary “workhorse” funcons of URSA-II
MCA. Each of these is described fully below.
Full
This hides all panels and makes the spectrum display as large as possible within the connes of the window
borders.
Hardware
This displays the Hardware Panel for adjusng the URSA-II hardware controls. To adjust
otherHardware sengs, the “Allow Edit” checkbox must be checked.
High Voltage can be adjusted by either directly entering a number in the High Voltage
input box or by using the up/down buons immediately to its right. When entering the
value directly, you can use any value between 0 and 2000 V, including decimal values.
When using the up/down buons, HV is increased/decreased in 1 V increments. Aer
changing the displayed HV value, the “Set HV” buon will become enabled. Pressing this
buon will apply the seng to the URSAII.
If an acquision is currently underway, it will automacally pause while the new seng is
applied then resume using the new seng.
If Ramp HV is not checked, the high voltage will change as instantaneously as possible. This
is usually ne for most detectors. If needed, Ramp HV can be checked and the high voltage
will always be changed at the rate displayed. This can range from 6 to 219 seconds per 100 volts.
The detector Input and Polarity can be selected from the dropdown menu. Input 1 is the series “C” connector

16
where signal and high voltage are carried on the same line. Input 2 is the separate connectors for signal and
high voltage, BNC and SHV respecvely. If “Shaped Input, Posive Polarity” is used, either of the inputs can be
used. Note: If a shaped input is used, Coarse and Fine Gain controls will have no eect on the spectrum input.
Also, take care to ensure that shaped pulses are kept in the 0 to 5V range; an aenuator may be required.
Coarse Gain is adjusted using the “Coarse Gain” dropdown menu. The coarse gain ranges are x2, x4, x15, x35,
x125, and x250. Coarse gain mes ne gain equals overall gain. Aer changing the coarse gain value, the “Set
Gain” buon will become enabled. Pressing this buon will apply the seng to the URSA-II. If an acquision
is currently underway, it will automacally pause while the new seng is applied then resume using the new
seng.
Fine Gain can be adjusted either by clicking on the slider bar or by clicking the arrow keys to the right and
le of the control. The ne gain can be adjusted in 255 steps from (approximately) x0.004 to (approximately)
x1, and the approximate gain value is displayed immediately above and to the le. Overall gain (coarse gain
mes ne gain) is isplayed immediately above and to the right. Aer changing the Fine Gain value, the “Set
Fine” buon will become enabled. Pressing this buon will apply the seng to the URSA-II. If an acquision
is currently underway, it will automacally pause while the new seng is applied then resume using the new
seng.
Use the Fine Gain control to perform small “nudges” to compensate for spectrum dri caused by temperature
changes in the detector. If an even smaller shi in gain is needed, try adjusng the high voltage by ny
increments (including decimal values).
Threshold can be adjusted by either directly entering a number in the Threshold input box or by using
the up/down buons immediately to its right. When entering the value directly, you can use any whole
number between 0 and 2498mV. When using the up/down buons, Threshold is increased/decreased in 1
mV increments. Aer changing the displayed Threshold value, the “Set Thsh” buon will become enabled.
Pressing this buon will apply the seng to the URSA-II. If an acquision is currently underway, it will
automacally pause while the new seng is applied then resume using the new seng. Note: High values of
gain will likely necessitate increasing the threshold.
Shaping Time can be adjusted using the dropdown menu. Possible values are 0.25, 0.5, 1, 2, 4, 6, 8, and 10
μseconds.
For the vast majority of cases, a shaping of 1 μSec is appropriate. Aer changing the shaping me value,
the “Set S.T.” buon will become enabled. Pressing this buon will apply the seng to the URSA-II. If an
acquision is currently underway, it will automacally pause while the new seng is applied then resume
using the new seng.
ROI Panel
This displays the ROI Panel, for creang or adjusng ROIs (Regions of Interest). You will not be able to open
this panelunl an energy calibraon has been performed. The intricacies of this panel are discussed in detail
below.
“Current ROI Set Name:” displays the lename of the currently loaded ROI set. If no le is displayed, no ROI set
is currently loaded. Note: A small display will appear below “Current ROI Set Name:” (not shown in the display

17
above) that ags the fact that the current ROI set has been altered but not yet been saved.
The small panel (“Drag cursor to”) immediately below this normally has “Zoom (normal)” checked. This means
that clicking and dragging on the spectrum will have the normal eect of zooming and un-zooming the display.
If “Set ROI” is checked instead, clicking and dragging in the spectrum will dene an ROI. Aer seng an ROI
this way, the panel will revert to “Zoom (normal).”
Moving down and to the le is a small gray box displaying the current “ROI #” with “le” and “right” arrow
buons. This box displays which specic ROI is being edited within the greater ROI set. Click the arrow buons
to change the current ROI. The currently selected ROI is shown in fuchsia on the spectrum display. To create a
new specic ROI, advance the ROI number to one that contains no data. Up to 50 ROIs may be dened within
an ROI set.
Immediately below the “ROI #” is the “ROI Name” input box. Use this secon to provide a descripve name for
each individual ROI within the greater ROI set. This name becomes the one displayed in the spectrum status
bar, and is also used to idenfy individual ROIs in analysis reports.
Approximately in the middle of the ROI panel are two radio buon controls, “Dbl Click to Set Starng Energy
(keV)” and “Dbl Click to Set Ending Energy (keV).” When the ROI Panel is visible, double clicking on the
spectrum will set either the lower or upper bound of an ROI (depending on which control is selected).
The controls immediately below provide a display of the lower and upper bounds of a specic ROI. Using the
buons with the single arrow will advance the boundary of the specic ROI up or down one channel; the
buons with the double arrow will advance the boundary up or down 10 channels. The energy associated with
this channel will be updated in the input box.
The “Kill ROI” buon will completely delete the currently selected specic ROI, without giving any addional
warning. “Load ROI Set” opens a dialog box to select an ROI set. If the current ROI set has not been saved since
it was last altered, a warning will be displayed and you will be given an opportunity to save the current ROI set
before connuing. If the ROI set is not explicitly saved, all changes will be lost when a new ROI set is loaded.

18
The “Cancel” buon will only be enabled when the current ROI set has been altered or edited in any way since
it was last saved. Using this funcon will re-load the current ROI set as it was last saved.
The “New ROI Set” buon clears the current ROI set from URSA-II MCA (if it has not been saved, you will be
given the opportunity to do this rst) so that a new ROI set can be created. You will be prompted to rst name
the ROI set, which you must do in order to connue.
Eciency
This displays the Eciency Calibraon Panel. This eciency calibraon is based on an ROI set, but the same
calibraon is also used when performing peak- or library-based spectrum analyses. An ROI set, therefore, must
be created and/or loaded before this panel is available. Eciency calibraons are unique to specic URSA-II/
ROI le/Detector combinaons.
“Current ROI Set Name:” displays the lename of the currently loaded ROI set. Note: A small display will
appear below “Current ROI Set Name:” (not shown in the display above) that ags the fact that the current ROI
set has been altered using the ROI Panel but not yet saved. It is not recommended that an eciency calibraon
be performed using an unsaved ROI set.
If the “Allow Edit” box is checked, the controls on this panel will be unlocked for eding. If this box is not
checked, the data for the last calibraon can be viewed but not altered.
The arrow buons will change the currently selected specic ROI within the greater ROI set and the data
on this panel will reect only that specic ROI, as will any modicaons. The currently selected ROI will be
displayed in fuchsia.
The gray boxes display specic ROI data, including the eciency (as a percentage of counts detected per
disintegraon) if a calibraon has been previously performed.
The “Assign ROI as Unknown” checkbox allows a specic ROI within an ROI set to be designated as one that is
not contained in the eciency calibraon source being used.
The “Associated Nuclide” control contains a dropdown list of all enabled nuclides in the current library. Prior
to performing an eciency calibraon, a nuclide must be assigned to each ROI within the ROI set by clicking
on one of the items in the list. If the needed nuclide is not in this list, the library must be edited to enable this
nuclide.
The “Associated Peak” control contains a dropdown list of all enabled peaks (for the nuclide selected as the
associated nuclide) in the current library. Prior to performing an eciency calibraon, one of these peaks
must be assigned to each ROI within the ROI set by clicking on one of the items in the list. If a needed peak or
mulplet is not on the list, the library must be edited to enable or add this peak or mulplet.

19
Enter the acvity of the specic isotope in the “Acvity” input box. This must be performed for all ROIs within
the ROI set prior to performing an eciency calibraon. Use the “Units” dropdown list to assign units to the
acvity. Note: The acvity units must be the same for all acvies entered. Changing the units for one specic
ROI will change the units assigned to all other ROIs within the ROI set.
The “ROI E. Cal!” buon performs an eciency calibraon by applying the data entered on the Eciency
Calibraon
Panel against the currently displayed spectrum. If no data is contained in the spectrum, or if all the elds are
not lled in, rated and the eciency calibraon will be aborted.
The “Cancel” buon will make any alteraons made on the Eciency Calibraon Panel revert back to the ones
used in the most recent eciency calibraon.
Every me an eciency calibraon is performed, a report is generated and stored in the URSA-II Cal Files
directory.
This report can be viewed, printed, or saved by clicking the “Report…” buon. Note: The contents of the report
and use of the report window are discussed in detail in other porons of this manual.
Peak-Based
This displays the Peak-Based Panel for performing peak searches, and for performing isotopic idencaon and
peakbased quantave analysis.
Clicking the “Find Peaks” buon causes URSA-II MCA to search the currently displayed spectrum for denable
peaks.
These will be displayed on the spectrum in green, with a line indicang the peak centroid. The collecon of
found peaks acts a bit like a temporary ROI set, and the currently selected peak (which will be the lemost one
immediately following a peak search) will be displayed in fuchsia.
Clicking the “Report…” buon makes URSA-II MCA perform a qualitave analysis. If an eciency calibraon
has been performed, a quantave analysis will also be preformed. This will then be displayed on a “report”
screen, where it can be viewed, printed, or saved. Note: The contents of this report and use of the report
screen are discussed in detail in other porons of this manual.
The “Clear Peaks” buon will erase all found peaks.The “Make ROI” buon allows the user to take a group of

20
found peaks and convert them to an ROI set.
The “Peak Search Sensivity” control aects how “disnct” a peak needs to be before it is agged as “found.” If
it appears that to many peaks have been idened in a peak search, try lowering this value. And vice-versa…
The four radio buons determine what which method is used in idenfying the nuclide associated with a peak.
The top item will associate a peak with a nuclide if the library energy is within the stated energy range of the
centroid and is the
default idencaon method, using +/- 3 keV. The next item, if selected, will associate a peak with a nuclide
if the library energy is within the stated percentage of the library energy. The third item, if selected, will
associate a peak with a
nuclide if the library energy is anywhere within the area of the found peak. The fourth item, if selected, will
associate a peak with a nuclide if the library energy is anywhere within the FWHM (full width at half maximum)
calculated for the found peak.
There has been no computer program ever wrien that surpasses an experienced human eye at discriminang
whether a given poron of a spectrum represents a peak or not. Therefore, URSA-II MCA allows the user wide
latude in eding (or ignoring) the results of the computerized peak search.
If the “Allow Edit” box is selected, the controls for eding the found peaks are enabled.
When “Double Click Adds Peak” is selected, double clicking on a poron of the spectrum will add a “found
peak.” This new peak is treated as the others found by the computerized search, and this method of adding
“found peaks” may beused instead of or as a supplement to the computerized search.
When “Show FWHM” is checked, the FWHM (full width at half maximum) calculated for each found peak will
be displayed on the spectrum.
The arrow buons below “Selected Peak” change the currently selected found peak, which is indicated by the
displayed number and highlighted in fuchsia in the spectrum display. Data displayed and edits made will apply
only to the currently selected found peak.
Values for the Centroid, Le Edge, and Right Edge can be altered by using the single and double arrow buons.
The single arrow buons will move the relevant value up or down the spectrum by one channel, and the
double arrow buons will move the relevant value up or down the spectrum by 10 channels. The current value
will be displayed (in keV) in the associated gray box.
Finally, the “Kill Peak” buon will permanently delete the currently selected found peak (whether found by the
computer search or manually assigned).
ROI-Based
This displays the ROI-based Quantave Analysis Panel.
Clicking the “ROI Analysis” buon performs an ROI by ROI analysis of the currently displayed spectrum,
calculang acvies for each ROI. A summary of this data is displayed for each ROI. Change the currently
selected ROI (indicated by fuchsia on the spectrum display) by clicking the arrow buons.
Clicking the “Report…” buon displays the detailed results of the ROI-based quantave analysis. From the
“report” screen, this data can be viewed, printed, or saved. Note: The contents of this report and use of the
report screen are discussed in detail in other porons of this manual.
Sample Info
This displays the Sample Data Panel for entering sample descripons and quanes.