Hours on the Linac 7835 Power Amplifiers

Last data update: Mon Mar 16 11:30:10 CST 2009

Station Tube S/N Gradient Filament A Hours Days Fraction of
median* life
1 BA1 1 6610 5155 214 0.32
2 BA2 0.98 6740 6067 252 0.56
3 AZ4R1 0.98 6703 2922 121 0.27
4 BA3 0.96 6823 5220 217 0.48
5 BA4R1 0.99 6820 3240 135 0.3
7 BA6 0 0 317 13 0.02

*Median lifetime for tubes is about 10750 hours (15750 for tank 1). This is 447 days (656 for tank 1).

Spare 7835 Inventory

  • N27R8, 62 hours
  • A20R8, 219 hours
  • A1R9, 388 hours
  • C2R7, 0 hours
  • A30R7, 0 hours
  • BK1, 214 hours
  • N49R7, 474 hours
  • BA11, 0 hours
  • BV7R1, 0 hours
  • BK3R2, 0 hours
  • BV6R1, 0 hours
  • BV8R1, 0 hours

    • 7835 Delivery Schedule

    Regular Deliveries
    TubeDeliveryStatusOwner
    BK1 Unknown Returned to Burle 12/05 FNAL
    New 12/06 FNAL
    		Bulk Order of New Tubes (Feb, 2005)
    Order completed on April 4, 2006
    All delivery dates are estimates
    Last modified: Tue Sep 20 09:00:55 CDT 2006

    The following tubes are getter-less:

    Klystron Hours

    ModuleMnf*S/NHoursDaysYearsInternal
    Vacuum
    uA
    0 V L122 126994 5291 14.4 0.17
    V V L113 130706 5446 14.9 0.00
    1 L 0005R1 41605 1733 4.7 0.00
    2 L 0004 129710 5404 14.7 0.00
    3 L 0006 114094 4753 13 0.05
    4 L 0016 44447 1851 5 0.06
    5 L 0007 132907 5537 15.1 0.01
    6 L 0013R1 70384 2932 8 0.21
    7 L 0015 115064 4794 13.1 0.44
    D V A21 112872 4703 12.8 0.00

    *Mnf = "Manufacturer", V is Varian VKP-7955 and L is L3 (Litton) L-5859

    Spare Klystron Inventory

  • V_K107, 0 hours
  • V_L026Z, 8086 hours
  • L_0003, 2194 hours
  • L_0010, 72076 hours
  • L_0011, 37163 hours
  • L_0017, 0 hours
  • L_0018, 0 hours
  • L_0019, 0 hours
  • L_0020, 0 hours
  • L_0021, 0 hours

    • The last two klystron to fail were in KRF4, S/N 0009, at 83278 hours on November 14, 2003 and in KRF1, S/N 0002R1, at 29345 hours, on December 23, 2003. These klystrons failed due to severe vacuum problems. We have replaced two other klystrons since 1993 (at KRF1 and at KRF6).

    Of all the tube that have failed, 5 have failed offline with essentially no hours on them (due to vacuum problems). Of the failed tubes with significant hours, they had 83278 (S/N 0009), 64000, 43800, 37000, 29345 (S/N 0002R1) and 27000 hours when they failed..

    The delivery schedule for the klystrons being rebuilt is as follows:

    TubeDeliveryComments
    0014 September 2005
    0008 October 2005
    Schedule Last modified: Fri Aug 26 13:48:44 CDT 2005

    Last data update: Mon Mar 16 11:30:10 CST 2009