# Presentation: 030191

## LINAC PROTON SOURCE MODULATORS

- FERMILAB

- Dan Wolff/Howie Pfeffer

## MODULATOR SPECS

-  Output Voltage:              120kV
-  Output Current:               140 amps
-  Output Pulse Length:        4.5 ms
-  Pulse Rate:                       3 Hz
-  Input Voltage:                  480 VAC
-  Spark Energy Limit:           20 joules
-  Regulation (incl. slope):     1 % (?)
-  Design should minimize cost for upgrade
-   to 10 Hz pulse rate at 1.5 ms pulse width.

- Dan Wolff/Howie Pfeffer

## POTENTIAL MODULATOR TECHNOLOGIES

**SNS **– High Frequency Switcher
-  +   Small Size
-  +  Being commercially produced
-  -   As yet, unproven operational reliability
-  -   Passive circuit on secondary to control spark energy
-      deserves further investigation
-  -   HV/HF Transformer is tricky.  Is it reliable?
-  -   Pulse flattening yet to be demonstrated

-    **Miss-Matched PFN** – Russian Idea, not demonstrated
- 	+   No Bouncer Needed
- 	+   Interesting, might be more reliable
- 	-   Need to build one

-    **FNAL (Bouncer-type) with Updated Technology**
- 	*  Higher  Voltage IGBTs,  New Caps, New Controls

- Dan Wolff/Howie Pfeffer

## FNAL Bouncer-type 4.5 ms Modulator “Simplified” Schematic

- Dan Wolff/Howie Pfeffer

## Bouncer-type Modulator with Updated Technology

- IGBT Switch:
- Using New Higher Voltage Devices:
-      50% reduction in cost and physical size

-    Main Capacitor Bank:
- Using New “HAZY” Self-Healing Polypropylene Capacitors
- 50% Reduction in Cap Cost and Physical Size

-    Modulator Controls:
- Using Lab G type – SM Components, fewer cable interconnects
- 25% reduction in parts, 50% reduction in labor

- Dan Wolff/Howie Pfeffer

## Bouncer-type Modulator - New Features

-   Boost Converter Regulation
-     - Goal is to achieve +/- 5% control/regulation
-     - Allows for multiple modulators fed from one charging power supply.

-   Smoothing Choke
-     - Series choke of sufficient size to limit AC line fluctuations to +/- 1%
-       (present Linac area AC lines 15Hz voltage distortion).
-     - If new Linac fed from dedicated 345kV transformer, above
-       requirement could be relaxed.

-   Redundant IGBT Switch Design
-     - Eliminating the Backup Switch:  20% reduction in cost
-     - BUT Requires redundancy in number of switch devices and gate controls
-     - Replaces Ignitrons with less expensive SCRs in crowbar circuit
-     - Eliminates very high current crowbars and associated noise
-     - Maybe a zero gains feature but better reliability

- Dan Wolff/Howie Pfeffer

## 4.5 ms Modulator Design Features thatminimize 1.5ms upgrade costs

- 2 parallel IGBT Switches
- Main Cap Bank designed to separated into 3.
- 	RMS current based on 10 Hz 1.5 ms operation
- Bouncer Caps and Inductors designed to be separated into 3.
- 	 RMS current based on 10 Hz 1.5 ms operation

- Charging Power Supply
- 	Assuming boost converter regulation works, the same charging PS could be used to power 3 of the 1.5 ms modulators.

- Dan Wolff/Howie Pfeffer

## Original FERMI TESLA MODULATOR – Parts Cost

- Pulse Transformer:    $108k
- Pwr Transformer:       $ 50k
- Main Cap Bank:         $ 31k
- Cabinet:                      $ 15k
- Other:                        $126k
-                Subtotal:     $330k
- IGBT Switch             Subtotal:  $ 50k
- Modulator Controls   Subtotal:  $ 40k

-   Pulser Parts Cost

-    TOTAL:   $420K

- Dan Wolff/Howie Pfeffer

**Notes:**
In your opening, establish the relevancy of the topic to the audience.  Give a brief preview of the presentation and establish value for the listeners.  Take into account your audience’s interest and expertise in the topic when choosing your vocabulary, examples, and illustrations.  Focus on the importance of the topic to your audience, and  you will have more attentive listeners.

## Original FERMI TESLA MODULATOR – Total Cost

- LABOR ESTIMATE:
- (Total parts cost) – (Pulse Transformer)
- $422k   -   $108k   =  $314k

-    PULSER PARTS ESTIMATE:         $420k

-    TOTAL (1996 $’s):   $735k

-    RF MODULES (Spark Detection):      $12k    (AWAG)

-    TOTAL:
- 	Inflation Since 1996 (8 yrs at 2.5%/yr) = 22%
- 	1.22 x $735k = $900k

- Dan Wolff/Howie Pfeffer

## Original Fermi TESLA Modulator Updated Technology cost savings

- Using New Higher Voltage Devices and eliminating the backup switch:
- $60k savings in labor and parts

-    Main Capacitor Bank:
- 	Using New “HAZY” Self-Healing Polypropylene Capacitors
-   $30k savings in labor and parts
-   $5k savings in Cabinet,  Reduced Service Building Size!

- Controls Upgrade:
-  $30k Savings in parts and labor

- Original Fermi TESLA Modulator Updated Technology cost savings

-    TOTAL:
- 	Inflation Since 1996 (8 yrs at 2.5%/yr) = 22%
- 	1.22 x ($735k-$125k) = $745k

-  Total updated technology savings:         $125k

- Dan Wolff/Howie Pfeffer

**Notes:**
Determine the best close for your audience and your presentation.  Close with a summary; offer options; recommend a strategy; suggest a plan; set a goal.  Keep your focus throughout your presentation, and you will more likely achieve your purpose.

## 4.5 ms Modulator Cost Estimate

- Pulse Transformer:    $108k       [ x sqrt(3) ]		$190k
- Pwr Transformer:       $ 50k       [same]			$50k
- Main Cap Bank:         $ 31k       [ x1/2  x3]		$50k
- Cabinet:                      $ 15k       [ x8/5 ]			$25k
- Other:                        $126k        [see notes]		$270k
-                                                                                  Subtotal:     $585k
- IGBT Switch             Subtotal:  $ 50k  [ x 4/10  x2]	$40k
- Modulator Controls   Subtotal:  $ 40k  [x 5/8]                       $25k

-    TOTAL parts:   $650K

- Dan Wolff/Howie Pfeffer

**Notes:**
                   		Original Modulator Costs	Scaled to 4.5ms Modulator
SCR Controller:   		$  7k        				7
     Machine shop:   	$  7k        				21
     Bouncer Choke:    	$  6k        				18
     Bouncer Caps:     	$  6k        				18
     Power Resistors: 	$  6k        				18
     Klystron Fil. PS   	$  5k         				5
     Solenoid PS:       	$  4k         				4
     480VAC Contactor: 	$  4k         				4
     HV Diodes:         	$  4k         				12
     Ignitron Tubes:    	$  4k         				12
     Other:             	$ 72k         				150
                                             			Total: 269k

## 4.5 ms Modulator Cost Estimate – Total Cost

- LABOR ESTIMATE:
- (Total parts cost) – (Pulse Transformer)
- $650k   -   $190k   =  $460k

-    PULSER PARTS ESTIMATE:         $650k

-    TOTAL parts and labor (1996 $’s):   $1122k

-    RF MODULES (Spark Detection):      $12k    (AWAG)

-    TOTAL:
- 	Inflation Since 1996 (8 yrs at 2.5%/yr) = 22%
- 	1.22 x $1122k = $1370k

- Dan Wolff/Howie Pfeffer

## ESTIMATED SIZE !Simple scaling, no attempt to optimize 

- Dan Wolff/Howie Pfeffer

## 4.5 ms ModulatorProject Organization

- Project Leader:			Howie Pfeffer
- Magnetics:				Chris Jensen
- Controls:				Jim Biggs (& P. Prieto)
- Switch, Cap Bank, Bouncer, Misc.,	Leon Bartelson
- 	and construction:
- Computer Simulations:			Dan Wolff

-  Estimated project time
-    Design, construction, and commissioning:   18 months
-    after $’s available.

- Dan Wolff/Howie Pfeffer